CSII Cardiovascular Systems Inc

You are cordially invited to attend a special meeting (including any adjournments or postponements thereof, the “Special Meeting”) of stockholders of Cardiovascular Systems, Inc. (“CSI”) to be held virtually on April 27, 2023, at 12:00 p.m., Central Time. The Special Meeting will be a virtual meeting that will be conducted live via webcast. You will be able to attend the Special Meeting online by visiting www.virtualshareholdermeeting.com/CSII2023SM. You will also be able to vote your Shares (as defined below) electronically at the Special Meeting.

At the Special Meeting, you will be asked to consider and vote on (i) a proposal to adopt the Agreement and Plan of Merger, dated February 8, 2023 (such agreement, as it may be amended, modified or supplemented from time to time, the “Merger Agreement”), by and among CSI, Abbott Laboratories, an Illinois corporation (“Abbott”), and Cobra Acquisition Co., a Delaware corporation and a wholly-owned subsidiary of Abbott (“Merger Sub”), providing for the acquisition of CSI by Abbott, (ii) a proposal to approve, on an advisory (non-binding) basis, the compensation that may be paid or become payable to CSI’s named executive officers that is based on or otherwise relates to the Merger Agreement, the Merger, and the other transactions contemplated by the Merger Agreement (the “Compensation Proposal”), and (iii) a proposal to approve the adjournment of the Special Meeting to a later date or dates, if necessary or appropriate, including to solicit additional proxies to approve the proposal to adopt the Merger Agreement if there are insufficient votes to adopt the Merger Agreement at the time of the Special Meeting (the “Adjournment Proposal”). Upon the terms and subject to the conditions of the Merger Agreement, Abbott will acquire CSI via the merger of Merger Sub with and into CSI, with the separate corporate existence of Merger Sub thereupon ceasing and CSI continuing as the surviving corporation and a wholly-owned subsidiary of Abbott (the “Merger”).

If the Merger is completed, you will be entitled to receive $20.00 in cash, without interest, for each share of CSI common stock, par value $0.001 per share (each, a “Share” and collectively, the “Shares”), that you own immediately prior to the time at which the Merger will become effective (unless you are entitled to and have properly exercised and not waived, withdrawn, failed to perfect or otherwise lost your appraisal rights), which represents a premium of approximately 50% to the closing price of the Shares on February 8, 2023, the last full trading day prior to the time at which the Merger Agreement, the Merger, and the other transactions contemplated by the Merger Agreement were approved by CSI’s Board of Directors (the “Board of Directors”), the Merger Agreement was executed by the parties and entry into the Merger Agreement was publicly announced.

The Board of Directors, after considering the factors more fully described in the enclosed proxy statement, has unanimously: (i) determined that the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement are fair to, advisable and in the best interests of CSI and its stockholders, (ii) authorized and approved the execution, delivery and performance of the Merger Agreement by and on behalf of CSI, (iii) resolved to recommend the adoption of the Merger Agreement and the transactions contemplated by the Merger Agreement by the stockholders of CSI, and (iv) directed that the Merger Agreement be submitted to the stockholders of CSI for adoption.

The Board of Directors unanimously recommends that you vote: (1) “FOR” the adoption of the Merger Agreement; (2) “FOR” the approval, on an advisory (non-binding) basis, of the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

The accompanying proxy statement provides detailed information about the Merger Agreement, the Merger, the other transactions contemplated by the Merger Agreement, and the Special Meeting. A copy of the Merger Agreement is attached as Annex A to the proxy statement. We urge you to read both the proxy statement and Merger Agreement carefully in their entirety.

The proxy statement also describes the actions and determinations of the Board of Directors in connection with its evaluation of the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement. You should carefully read and consider the entire proxy statement and its annexes, including, but not limited to, the Merger Agreement, as they contain important information about, among other things, the Merger and the other transactions contemplated by the Merger Agreement, and how they affect you.

Whether or not you plan to attend the Special Meeting virtually, please sign, date and return, as promptly as possible, the enclosed proxy card in the accompanying prepaid reply envelope or grant your proxy electronically over the Internet or by telephone (using the instructions provided in the enclosed proxy card). If you attend, and vote at, the Special Meeting, then your vote at the Special Meeting will revoke any proxy that you have previously submitted.

If you hold your Shares in “street name,” you should instruct your bank, broker or other nominee how to vote your Shares in accordance with the voting instruction form that you will receive from your bank, broker or other nominee. Your bank, broker or other nominee cannot vote on any of the proposals, including the proposal to adopt the Merger Agreement, without your instructions.

Your vote is very important, regardless of the number of Shares that you own. We cannot complete the Merger unless the proposal to adopt the Merger Agreement is approved by the affirmative vote of the holders of a majority of all outstanding Shares as of the close of business on March 14, 2023, which is the record date for the Special Meeting.

Stockholders who do not vote in favor of the proposal to adopt the Merger Agreement, and who object in writing to the Merger prior to the vote on the proposal to adopt the Merger Agreement at the Special Meeting and comply with all of the applicable requirements of Delaware law, which are summarized in the section titled “The Merger—Appraisal Rights” in the accompanying proxy statement and reproduced in their entirety in Annex C to the accompanying proxy statement, will be entitled to appraisal rights to obtain the “fair value” of their Shares.

If you have any questions concerning the Merger Agreement, the Merger, the other transactions contemplated by the Merger Agreement, the Special Meeting or the proxy statement, would like additional copies of the proxy statement or need help voting your Shares, please contact our proxy solicitor:

Neither the Securities and Exchange Commission nor any state securities regulatory agency has approved or disapproved the Merger, passed upon the merits or fairness of the Merger, the Merger Agreement or the other transactions contemplated by the Merger Agreement or passed upon the adequacy or accuracy of the disclosure in this document and any documents incorporated by reference. Any representation to the contrary is a criminal offense.

This proxy statement is dated March 23, 2023 and is first being mailed to stockholders on or about March 23, 2023.

The following questions and answers address some commonly asked questions regarding the Merger, the Merger Agreement and the Special Meeting. These questions and answers may not address all questions that are important to you. You should carefully read and consider the more detailed information contained elsewhere in this proxy statement and the annexes to this proxy statement, including the Merger Agreement, along with all of the documents we refer to in this proxy statement, as they contain important information about, among other things, the Merger and the other transactions contemplated by the Merger Agreement and how they affect you. You may obtain the information incorporated by reference in this proxy statement without charge by following the instructions in the section of this proxy statement titled “Where You Can Find More Information.”

This proxy statement contains certain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including statements with respect to Merger and the financial condition, results of operations and businesses of CSI. Some of these statements can be identified by terms and phrases such as “believes,” “expects,” “potential,” “continues,” “may,” “will,” “should,” “could,” “seeks,” “predicts,” “intends,” “trends,” “plans,” “estimates,” “anticipates” or the negative version of these words or other comparable words. CSI cautions readers of this proxy statement that such “forward looking statements,” wherever they occur in this proxy statement or in other statements attributable to CSI, are necessarily estimates reflecting the judgment of CSI’s senior management and involve a number of risks and uncertainties that could cause actual results to differ materially from those suggested by the “forward looking statements.”

Factors that could cause CSI’s actual results to differ materially from those expressed or implied in such forward-looking statements include, but are not limited to, the risks detailed in CSI’s filings with the SEC, including in its most recent filings on Forms 10-K and 10-Q, factors and matters described or incorporated by reference in this proxy statement, and the following factors:

Additional factors that could cause CSI’s actual outcomes or results to differ materially from those described in the forward-looking statements can be found in the “Risk Factors” sections of CSI’s Annual Report on Form 10-K for the period ended June 30, 2022 and Quarterly Reports on Form 10-Q for the periods ended September 30, 2022 and December 31, 2022, as such factors may be further updated from time to time in CSI’s other filings with the SEC. These reports are or will be accessible on the SEC’s website at www.sec.gov. These factors should not be construed as exhaustive and should be read in conjunction with the other cautionary statements that are included in CSI’s filings with the SEC.

Except as required by applicable law, we undertake no obligation to publicly update forward-looking statements, whether as a result of new information, future events or otherwise. Our stockholders are advised, however, to consult any future disclosures we make on related subjects as may be detailed in our other filings made from time to time with the SEC.

We will hold the Special Meeting virtually on April 27, 2023, at 12:00 p.m., Central Time, via live webcast on the Internet and, if applicable, at any adjournment or postponement thereof. You will be able to attend and vote your Shares during the Special Meeting via a live webcast available at www.virtualshareholdermeeting.com/CSII2023SM.

At the Special Meeting, we will ask the stockholders to vote on proposals to: (i) adopt the Merger Agreement; (ii) approve, on an advisory (non-binding) basis, the Compensation Proposal; and (iii) approve the Adjournment Proposal.

We do not expect that any matters other than the proposals set forth above will be brought before the Special Meeting and only matters specified in the notice of the Special Meeting may be acted upon at the Special Meeting.

Our stockholders must approve the proposal to adopt the Merger Agreement in order for the Merger to be consummated. If our stockholders fail to approve the proposal to adopt the Merger Agreement, the Merger will not be consummated. A copy of the Merger Agreement is attached as Annex A to this proxy statement, which we urge you to read carefully in its entirety.

Only stockholders of record as of the Record Date are entitled to notice of the Special Meeting and to vote at the Special Meeting. A list of stockholders entitled to vote at the Special Meeting will be available at our principal executive offices located at 1225 Old Highway 8 NW, St. Paul, Minnesota 55112, during regular business hours for a period of no less than 10 days before the Special Meeting.

The presence, in person or by proxy duly authorized, of the holders of record of a majority of the outstanding Shares entitled to vote shall constitute a quorum for the transaction of business at the Special Meeting. Assuming the Special Meeting is held solely by means of remote communication, as it is currently scheduled to be, only Shares present virtually or represented by proxy at the Special Meeting will be counted in determining whether a quorum is present. As of the Record Date, there were 42,198,048 Shares outstanding and entitled to vote at the Special Meeting, meaning that 21,099,025 Shares must be represented virtually or by proxy at the Special Meeting to have a quorum. In the event that a quorum is not present at the Special Meeting, it is expected that the Special Meeting will be adjourned to solicit additional proxies to approve the proposal to adopt the Merger Agreement.

The affirmative vote of the holders of a majority of all outstanding Shares on the Record Date is required to adopt the Merger Agreement. As of the Record Date, 21,099,025 Shares constitute a majority of the outstanding Shares. Adoption of the Merger Agreement by the stockholders is a condition to the closing of the Merger.

The affirmative vote of the majority of the Shares present in person or represented by proxy duly authorized at the Special Meeting and entitled to vote generally on the subject matter is required to approve the Compensation Proposal, on an advisory (non-binding) basis, provided a quorum is present. Assuming the Special Meeting is held solely by means of remote communication, as it is currently scheduled to be, only Shares present virtually or represented by proxy at the Special Meeting will be able to be voted.

Approval of the Adjournment Proposal requires either (i) if a quorum is present, the affirmative vote of the majority of the Shares present in person or represented by proxy duly authorized at the Special Meeting and entitled to vote generally on the subject matter or (ii) if a quorum is not present, the vote of the holders of a majority of the Shares represented at the Special Meeting.

An abstention represents a stockholder’s affirmative choice to decline to vote on a proposal. However, abstentions are counted as Shares present or represented by proxy at the Special Meeting for the purposes of determining whether a quorum is present at the Special Meeting. As a result, an abstention of any of the

aforementioned proposals will be counted for purposes of determining the presence or absence of a quorum, but will have the same effect and be counted as a vote “AGAINST” each of the proposal to adopt the Merger Agreement, the Compensation Proposal and the Adjournment Proposal.

Failure to vote your Shares (including a failure of your broker, bank or other nominee to votes Shares held on your behalf) will count as a vote “AGAINST” the proposal to adopt the Merger Agreement. If your Shares are not deemed present or represented by proxy at the Special Meeting, then a failure to vote will not have any effect on the Adjournment Proposal or the Compensation Proposal. If your Shares are deemed present or represented by proxy, then a failure to vote your Shares will have the same effect as a vote “AGAINST” the Adjournment Proposal only if a quorum is not present, and will have no effect on the Compensation Proposal or, if a quorum is present, on the Adjournment Proposal.

Because brokers, banks and other nominees do not have discretionary voting authority with respect to the proposal to adopt the Merger Agreement, the Compensation Proposal or the Adjournment Proposal, if a beneficial owner of Shares held in “street name” does not give voting instructions to the broker, bank or other nominee with respect to any of the proposals, then those Shares may not be voted on your behalf for any proposal, will not be deemed present or represented by proxy at the Special Meeting and will not be counted for purposes of determining whether a quorum is present at the Special Meeting. However, if a beneficial owner of Shares held in “street name” gives voting instructions to the broker, bank or other nominee with respect to at least one of the proposals, but gives no instruction as to one or more of the other proposals, then those Shares will be deemed present at the Special Meeting for purposes of establishing a quorum at the Special Meeting, will be voted as instructed with respect to any proposal as to which instructions were given and will not be voted with respect to any other proposal.

As of the Record Date, our directors and executive officers beneficially owned and were entitled to vote, in the aggregate, 1,387,360 Shares, representing approximately 3.3% of the Shares outstanding on the Record Date (and approximately 3.9% of the Shares outstanding when taking into account CSI RSUs beneficially owned, in the aggregate, by our directors and executive officers).

Our directors and executive officers have informed us that they currently intend to vote all of their respective Shares (i) “FOR” the adoption of the Merger Agreement, (ii) “FOR” the approval, on an advisory (non-binding) basis, of the Compensation Proposal, and (iii) “FOR” the Adjournment Proposal.

If, on the Record Date, your Shares are registered directly in your name with our transfer agent, Broadridge Corporate Issuer Solutions, Inc., then you are a stockholder of record. As a stockholder of record, you may vote at the Special Meeting, vote by proxy using the enclosed proxy card (if you received paper copies of the proxy materials), vote by proxy over the telephone, or vote by proxy over the Internet. Whether or not you plan to attend the Special Meeting, we urge you to submit your proxy to ensure your vote is counted. You may still attend the Special Meeting and vote at that time even if you have already submitted your proxy.

We are providing Internet proxy voting to allow you to vote your Shares via proxy online, with procedures designed to ensure the authenticity and correctness of your proxy vote instructions. However, please be aware that you must bear any costs associated with your Internet access, such as usage charges from Internet access providers and telephone companies. These costs will also apply to virtual attendance at the Special Meeting.

the Merger Agreement, the Merger, and the other transactions contemplated by the Merger Agreement are fair to, advisable, and in the best interests of CSI and its stockholders, (ii) authorized and approved the execution, delivery and performance of the Merger Agreement by and on behalf of CSI, (iii) resolved to recommend the adoption of the Merger Agreement and the transactions contemplated by the Merger Agreement to the stockholders of CSI and (iv) directed that the Merger Agreement be submitted to the stockholders of CSI for adoption.

Accordingly, the Board of Directors unanimously recommends that you vote: (i) “FOR” the adoption of the Merger Agreement; (ii) “FOR” the approval, on an advisory (non-binding) basis, of the Compensation Proposal; and (iii) “FOR” the Adjournment Proposal.

The expense of soliciting proxies will be borne by CSI. CSI has retained D.F. King & Co., Inc., a proxy solicitation firm, to solicit proxies in connection with the Special Meeting at a cost of approximately $15,000, plus expenses. CSI will also indemnify D.F. King & Co., Inc. against certain losses arising out of its provisions of these services on our behalf. In addition, CSI may reimburse banks, brokers and other nominees representing beneficial owners of Shares for their expenses in forwarding soliciting materials to such beneficial owners. Proxies may also be solicited by our directors, officers and employees, personally or by telephone, email, fax, over the Internet or other means of communication. No additional compensation will be paid for such services.

The proxy statement is available on the investor relations page of our website at investors.csi360.com.

If you have any questions concerning the Merger Agreement, the Merger, the other transactions contemplated by the Merger Agreement, the Special Meeting or this proxy statement, would like additional copies of this proxy statement or need help voting your Shares, please contact our proxy solicitor:

The discussion of the Merger in this proxy statement is qualified by reference to the Merger Agreement, which is attached to this proxy statement as Annex A and incorporated into this proxy statement by reference. This summary does not purport to be complete and may not contain all of the information about the Merger that is important to you. You should read the Merger Agreement carefully in its entirety.

Cardiovascular Systems, Inc. is a medical technology company leading the way in the effort to successfully treat patients suffering from peripheral and coronary artery diseases, including those with arterial calcium, the most difficult form of arterial disease to treat. CSI is committed to clinical rigor, constant innovation and a defining drive to set the industry standard to deliver safe and effective medical devices that improve the lives of patients facing this difficult disease state. CSI has developed a patented orbital atherectomy systems (“OAS”) for both peripheral and coronary clinical applications. The primary base of CSI’s business is catheter-based platforms capable of treating a broad range of vessel sizes and plaque types, including calcified plaque, which address many of the limitations associated with other treatment alternatives. To date, more than 670,000 patients have been treated with our OAS devices and CSI continues to expand our business to serve more patients with cardiovascular disease.

The common stock of Cardiovascular Systems, Inc. is traded on Nasdaq under the ticker symbol “CSII.”

Cardiovascular Systems, Inc. was incorporated in Delaware in 2000. CSI’s principal executive office is located at 1225 Old Highway 8 Northwest, St. Paul, Minnesota 55112. CSI’s telephone number is (877) 274-0360 and CSI’s website is www.csi360.com. The information contained in or accessible through CSI’s website is not incorporated by reference into, and should not be considered part of, this proxy statement.

Additional information about CSI is contained in its public filings with the SEC, which filings are incorporated by reference herein. See the section of this proxy statement titled “Where You Can Find More Information.”

Abbott Laboratories, an Illinois corporation, is a global healthcare leader that helps people live more fully at all stages of life. Abbott’s portfolio of life-changing technologies spans the spectrum of healthcare, with leading businesses and products in diagnostics, medical devices, nutritionals and branded generic medicines. Abbott’s 115,000 colleagues serve people in more than 160 countries. Abbott shares are listed on the NYSE under the symbol “ABT.” Abbott shares are also listed on the Chicago Stock Exchange and traded on various regional and electronic exchanges. Outside of the U.S., Abbott shares are listed on the SIX Swiss Exchange. Abbott’s principal executive office is located at 100 Abbott Park Road, Abbott Park, Illinois 60064-6400. Abbott’s telephone number is (224) 667-6100.

Cobra Acquisition Co. is a Delaware corporation and wholly-owned subsidiary of Abbott that was formed solely for the purpose of entering into the Merger Agreement and consummating the transactions contemplated by the Merger Agreement, including the Merger. Merger Sub has not carried on any activities on or prior to the date of this proxy statement except for activities incidental to its formation and activities in connection with facilitating Abbott’s acquisition of CSI. Upon completion of the Merger, Merger Sub will merge with and into CSI and will cease to exist.

Merger Sub’s principal executive office is located at c/o Abbott Laboratories, 100 Abbott Park Road, Abbott Park, Illinois 60064-6400. Merger Sub’s telephone number is (224) 667-6100.

Upon the terms and subject to the conditions of the Merger Agreement, Merger Sub will merge with and into CSI, with the separate corporate existence of Merger Sub thereupon ceasing and CSI continuing as the surviving corporation and a wholly-owned subsidiary of Abbott. As a result of the Merger, the Shares will no

longer be publicly traded and will be delisted from Nasdaq. In addition, the Shares will be deregistered under the Exchange Act and CSI will no longer file periodic reports under the Exchange Act with the SEC. If the Merger is completed, as a result of the Merger, you will not own any shares of the capital stock of the surviving corporation or any additional capital stock of Abbott.

The Effective Time will occur upon the filing of a certificate of merger with the Secretary of State of the State of Delaware (or at such later time as CSI and Abbott may agree in writing and specify in the certificate of merger).

If the Merger Agreement is not adopted by the stockholders, or if the Merger is not completed for any other reason:

For more information, please see the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Termination Fees and Expenses.”

At the Effective Time, each Share issued and outstanding immediately prior to the Effective Time, other than Excluded Shares and Dissenting Shares, will be converted automatically into the right to receive the Merger Consideration.

At or before the closing of the Merger, Abbott will deposit or, cause to be deposited, with a paying agent, for the benefit of the holders of Shares (other than Excluded Shares and Dissenting Shares), cash in an amount sufficient to pay the aggregate Merger Consideration required to be paid under the Merger Agreement. For more information, please see the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Exchange and Payment Procedures.”

After the Merger is completed, you will have the right to receive the Merger Consideration in respect of each Share that you own, but you will no longer have any rights as a stockholder of CSI. Stockholders who properly exercise their appraisal rights have the right to receive payment for the “fair value” of their Shares determined pursuant to an appraisal proceeding, as contemplated by Delaware law. For more information, please see the section of this proxy statement titled “The Merger—Appraisal Rights.”

We are working toward completing the Merger as promptly as possible. In order to complete the Merger, CSI must obtain the Stockholder Approval described in this proxy statement, and the other closing conditions under the Merger Agreement must be satisfied or waived. The closing conditions include the expiration or termination of any waiting period under the HSR Act applicable to the Merger and the other transactions contemplated by the Merger Agreement (or any extension thereof including the expiration or termination of any timing agreement entered into with any governmental authority) and the receipt of all consents, approvals or authorizations of, declarations or filings with or notices to any governmental authority pursuant to any other applicable competition law or foreign investment law in connection with the consummation of the Merger and the transactions contemplated by the Merger Agreement, as reasonably determined by Abbott to be applicable to the Merger and the other transactions contemplated by the Merger Agreement, in each case, without the imposition of any Burdensome Condition (as defined in the section of this proxy statement titled “Proposal 1:

Adoption of the Merger Agreement—Regulatory Filings”). CSI and Abbott filed notification and report forms under the HSR Act with the DOJ and the FTC on March 13, 2023. Since the Merger is subject to a number of conditions, the exact timing of the Merger cannot be determined at this time. For more information, please see the section of this proxy statement titled “The Merger—Required Regulatory Approvals,” “Proposal 1: Adoption of the Merger Agreement—Regulatory Filings” and “Proposal 1: Adoption of the Merger Agreement—Conditions to the Closing of the Merger.”

The Board of Directors frequently reviews, with our senior management and with the assistance of our outside advisors, our strategic and financial alternatives in light of developments in our business, the markets in which we operate and compete, new technologies and therapeutic options for the patient population that we serve, healthcare coverage and reimbursement, the global economy, financial markets, and other geopolitical factors. Since March 2020, these assessments have been significantly informed by the impact of the COVID-19 pandemic on our business and prospects.

The COVID-19 pandemic caused us to experience ongoing disruptions in the interventional procedures that are performed using our products. Over time, procedures have been postponed as a result of reduced availability of physicians or catheter laboratory (cath lab) space to treat patients, the lack of vaccines, personal protective equipment and active virus test kits, patient care prioritization based upon the severity of the condition being treated, increased cost pressures and burdens on the overall healthcare infrastructure that resulted in reallocation of resources, customer staffing shortages, and governmental guidelines and restrictions. In addition, patients elected to defer or avoid treatment for certain interventional procedures that use our products due to anxiety about the potential spread of COVID-19 in healthcare facilities. Further, our personnel and the personnel of our distribution partners and sales agents experienced restrictions on their ability to access many customers, hospitals, cath labs and other medical facilities for sales activities, training and case support due to lower procedure volumes or they may have been deemed to be “non-essential” personnel by those facilities. While the COVID-19 pandemic has largely subsided, there remain several ongoing effects that have adversely affected and continue to adversely affect us, including labor shortages and turnover in the health care workforce, patient procedure deferrals and decreased access to sites of service for our representatives, all of which have continued into the current fiscal year. Since the start of the COVID-19 pandemic, we have also experienced an increase in employee turnover, including several positions at the senior-management level. Finally, in our fiscal 2022 and 2023 in particular, we have also experienced increased competition and reimbursement pressures, specifically in the office-based lab setting. As a result of these various factors, our results for fiscal 2022 were substantially below our initial expectations, and our results in fiscal 2023 through the first half have been similarly below our expectations.

Between October 2020 and May 2022, we were approached by five parties, either directly or through their representatives, who expressed an initial interest in learning more about CSI for the purpose of potentially considering an acquisition of CSI. Four of these parties were larger companies in the medical technology industry, and one was a private equity firm. None of these parties ultimately submitted any firm proposal to acquire us. In each case, we engaged in preliminary discussions with the party through a management presentation and, in the case of three of the parties, provision of certain confidential information pursuant to a confidentiality agreement. However, each of these five parties declined to pursue further discussions to acquire us following the initial meetings, and we did not at any point commence a sale process. The last of these declinations occurred in August 2022. In addition, during this period, Scott Ward, our Chairman, Chief Executive Officer and President was informed by an investment banking contact who he has known for several years that two other parties informed him that they were looking at CSI as a potential acquisition target, but neither of these parties engaged in any discussions with us, or, to our knowledge, this investment banking contact regarding an acquisition of CSI. Abbott was not one of these seven parties. In addition to these inquiries, Mr. Ward has periodically received inquiries from two similarly sized peer companies about a potential merger of equals at a future time. However, neither of those companies has made any proposal and no discussions commenced.

On November 3, 2022, we reported our financial results for the first quarter of fiscal 2023. On this day, our Shares closed on Nasdaq at $13.79 per Share, a decrease of 7.57% from the prior day’s closing price.

On November 7, 2022, Mr. Ward received a message from Robert Ford, the Chairman and Chief Executive Officer of Abbott, requesting a meeting that week. The message did not indicate the intended purpose of the

meeting. Mr. Ward returned the message and scheduled a meeting with Mr. Ford for November 9, 2022. On the same day, Mr. Ward received a message from a representative from a private equity firm, referred to in this proxy statement as “Party A.” Party A expressed an interest in potentially taking CSI private. Party A scheduled a meeting with Mr. Ward for November 23, 2022.

On November 8, 2022, the Board of Directors held a regularly scheduled meeting at its offices in St. Paul, Minnesota, at which Mr. Ward informed the Board of Directors of the inquiries from Abbott and Party A from the previous day. The agenda for the meeting included a review of strategic matters and, at the request of the Board of Directors, representatives of J.P. Morgan Securities LLC (“J.P. Morgan”) attended the meeting to present to the Board of Directors regarding the medical technology market and various strategic alternatives, as well as preliminary financial considerations regarding CSI, based on financial information and projections that we had presented publicly to analysts who cover CSI at a “Capital Markets Day” presentation held on August 3, 2022. For more information, please see the section of this proxy statement titled “The Merger—Financial Projections.” During the meeting, the Board of Directors reviewed and discussed with CSI management and the J.P. Morgan representatives the challenges facing us and the risks and opportunities for us and our business. The Board of Directors discussed that, while we were not cash-constrained, the longer-term investments required to finance our product development pipeline, along with risks to us, such as uncertainties in our markets, near-term operating performance challenges, financial market volatility, economic factors, supply chain interruptions and material shortages, the reimbursement environment and geopolitical factors, may make it prudent to consider seeking additional financing while also considering a variety of strategic options. The Board of Directors recognized that the headwinds in our business could make it difficult to reach our revenue goals, on which the product development pipeline funding plans are partially dependent, and a financing to provide additional support to the business and the product pipeline may be not only prudent, but necessary. Jeffrey Points, our Chief Financial Officer, provided information on our cash position, projections of continued near-term net losses, and projected uses of cash to fund the product development pipeline obligations and milestones. To fund our long-term goals, Mr. Points recommended that we would need to reduce our cash requirements, generate non-dilutive income from the current product portfolio, raise additional financing, or a combination of the foregoing. Mr. Points presented various options to achieve these goals, including restructuring the terms of current product development program agreements, selling geographic distribution rights, seeking financing (which could be in the form of bank debt, a private investment in public equity offering, common equity or convertible securities), and merger and sale options. The Board of Directors then returned to a discussion of the inquiries from Abbott and Party A from the previous day and discussed the potential of a sale of CSI, in the context of the strategic alternatives available to CSI. The Board of Directors agreed that CSI was not for sale at that time and that the Board of Directors would not commence a sale process in the absence of an acceptable proposal from a third party. The Board of Directors agreed that Mr. Ward should engage in discussions with both Abbott and Party A. The Board of Directors also agreed that CSI management should pursue a restructuring of our development project with Chansu Vascular Technologies, LLC for drug-coated balloons, which discussions were already underway. Finally, the Board of Directors asked CSI management to begin to explore potential financing options. CSI management agreed to keep the Board of Directors updated on these matters.

On November 9, 2022, Mr. Ward met in person with Mr. Ford in St. Paul, Minnesota. At this meeting, Mr. Ford expressed Abbott’s interest in a potential acquisition of CSI. Mr. Ward asked Mr. Ford for a non-binding proposal that could be reviewed by the Board of Directors. Mr. Ford informed Mr. Ward that Abbott would formulate a proposal. Following this meeting, Mr. Ward promptly informed the Board of Directors of this development.

On November 18, 2022, Mr. Ford called Mr. Ward and made a non-binding, verbal proposal to acquire CSI for a purchase price of $19.50 per Share in cash. Mr. Ford noted that Abbott’s offer reflected an approximately 40% premium to our recent Share prices and stated that Abbott’s rationale for the proposal was based upon a strong fit of our core orbital atherectomy business with Abbott’s complementary peripheral franchise, the strategic fit with Abbott’s business, and our proximity to Abbott operations in Minnesota, which would facilitate the integration process. Mr. Ford also communicated his view that the $19.50 per Share value also appropriately reflected the risks and uncertainties in our business, including our recent slower growth trajectory, the volatility in the macro environment (including the COVID-19 pandemic) and uncertainties regarding product pricing and reimbursement for our products in office-based labs. Mr. Ford informed Mr. Ward that Abbott did not intend to

engage an investment bank and that Abbott would not participate in a banker-led solicitation process if one were initiated by CSI. Mr. Ward acknowledged the proposal and informed Mr. Ford that he would meet with the Board of Directors about the proposal. On this day, our Shares closed on Nasdaq at $14.41 per Share.

Mr. Ward convened a meeting of the Board of Directors on that same day to discuss Abbott’s non-binding proposal. The meeting was also attended by Mr. Points and Alexander Rosenstein, our General Counsel and Corporate Secretary, along with representatives of J.P. Morgan. Mr. Rosenstein gave the Board of Directors an overview of its fiduciary duties and confidentiality considerations relating to strategic transactions. Representatives of J.P. Morgan joined the meeting to discuss the proposed per Share price of $19.50 from a financial perspective, including with respect to J.P. Morgan’s preliminary financial analysis that CSI reviewed at the November 8, 2022 Board of Directors meeting. The Board of Directors discussed the risks and substantial uncertainties in our business and the difficult environment in which we operate. While the Board of Directors reiterated that CSI was not for sale, the Board of Directors determined that Abbott’s proposal was worthy of further engagement to explore whether Abbott would submit a written proposal to acquire CSI at an increased offer price per Share for the Board of Directors to consider. Some members of the Board of Directors expressed a view that the proposed offer price of $19.50 per Share was within an acceptable range in order to engage in further discussions with Abbott regarding a potential acquisition of CSI. Following this discussion, the Board of Directors authorized and directed Mr. Ward to engage in additional discussions with Abbott and to seek a written proposal to acquire CSI at a higher proposed offer price. While seeking a potential increase in the price to be paid for CSI, the Board of Directors did not specify what an acceptable price would be and did not direct Mr. Ward to guide Abbott to a specific price. The Board of Directors also authorized Mr. Ward to engage J.P. Morgan as financial advisor for the discussions with Abbott and approved Dorsey & Whitney LLP (“Dorsey”), our primary outside counsel on strategic transaction matters, as our legal counsel for this matter.

Following this meeting, Mr. Ward called Mr. Ford to inform him that the Board of Directors appreciated Abbott’s interest in an acquisition, but believed the per Share price offered by Abbott was not sufficient for the Board of Directors to engage in negotiations with Abbott. Mr. Ward did not provide Mr. Ford with a specific price target that Abbott would need to meet in order for the Board of Directors to approve moving forward with a potential transaction. Mr. Ward expressed his opinion that a per Share price in the mid-$20s would be more attractive to the Board of Directors. Mr. Ford informed Mr. Ward that he thought $19.50 per Share was their best offer but he would consider this response and come back to Mr. Ward after discussing internally. The same day, J.P. Morgan sent a proposed engagement letter to us for review.

On November 23, 2022, Mr. Ward held a telephone conference with representatives of Party A. Party A expressed an interest in potentially acquiring CSI and building a privately held medical technology franchise. Mr. Ward provided an overview of CSI based on non-confidential information and engaged in discussion with Party A about our business and prospects. Mr. Ward suggested a follow-up meeting for early December, and a meeting was later scheduled for December 16, 2022.

On November 30, 2022, Mr. Ford called Mr. Ward and informed him that Abbott would send a written, non-binding proposal with an updated offer, which Mr. Ford characterized would be Abbott’s “best offer.” Mr. Ford reiterated that Abbott would not participate in a banker-led solicitation process if CSI were to initiate one.

On December 2, 2022, Abbott sent Mr. Ward a letter containing Abbott’s non-binding indication of interest to acquire CSI for a purchase price of $20.00 per Share in cash, using Abbott’s available funds or existing borrowing capacity. Abbott’s letter did not provide detailed information regarding proposed timing or due diligence process. On this day, our Shares closed on Nasdaq at $13.93 per Share. Mr. Ward called a meeting of the Board of Directors for December 5, 2022 to discuss the new proposal.

On December 5, 2022, the Board of Directors held a meeting by video conference. J.P. Morgan presented a preliminary financial analysis based on financial projections reviewed with the Board of Directors at the November 8, 2022 meeting and analyzed Abbott’s offer in the context of this preliminary analysis. The Board of Directors considered the benefits and risks of reaching out to other potential acquirers, taking into account Mr. Ford’s statements to Mr. Ward on multiple occasions that Abbott would not participate in a banker-led solicitation process, as well as the lack of substantive negotiations resulting from prior approaches from potential acquirers of CSI. The Board of Directors also discussed the relative benefits and risks around pursuing additional financing, as discussed at the November 8, 2022 Board of Directors meeting, which could be substantially

dilutive to our current stockholders. During this discussion, some members of the Board of Directors again expressed a view that the initial proposed offer price of $19.50 per Share was within an acceptable range in order to engage in further discussions with Abbott regarding a potential acquisition of CSI. After this discussion, the Board of Directors agreed that Mr. Ward should communicate to Mr. Ford that, were Abbott to propose an acquisition in the range of $22-23 per Share, which was closer to the highest closing price of our stock in the prior 52 weeks of $23.34 per Share, the Board of Directors would be prepared to consider a transaction with Abbott. The Board of Directors also concluded that CSI should not reach out to other potentially interested parties at this time, given the risk that doing so could cause Abbott to withdraw from discussions and deny CSI the opportunity to create stockholder value through a transaction with Abbott. The Board of Directors also approved the engagement letter with J.P. Morgan, the terms of which had been negotiated prior to this meeting. At this meeting, Mr. Rosenstein gave another overview of the Board of Directors’ fiduciary duties relating to strategic transactions. The Board of Directors formed a Transaction Committee of the Board of Directors that could more efficiently consider, discuss and approve matters relating to Abbott’s proposal and any transaction that may arise as part of the process (the “Transaction Committee”). The Transaction Committee was authorized to take all actions necessary to review, evaluate and consider potential strategic acquisitions and merger transactions that CSI could pursue and any potential unsolicited proposals regarding acquisition or merger transactions involving CSI, to negotiate the terms of any such transaction, to authorize appropriate officers of CSI to take actions relating to any such transactions, to make recommendations to the Board of Directors relating to any such transactions (including the ability to reject any transaction), and any other matter relating to transactions that the Transaction Committee believed to be necessary or advisable. The Transaction Committee was comprised of the following Board of Directors members: Augustine Lawlor, as Chair, and Martha Goldberg Aronson and Stephen Stenbeck, each of whom are independent directors and were chosen based on their experience with strategic transactions, existing roles on the Board of Directors and willingness to serve on the Transaction Committee. The Transaction Committee was not formed as a result of any actual or perceived conflicts of interest.

On December 6, 2022, Mr. Ward called Mr. Ford and conveyed the Board of Directors’ views that a valuation at a stock price closer to our 52-week high, or approximately $23.50 per Share, was within a range in which the Board of Directors would be prepared to consider a transaction with Abbott, and also indicated that we were seeking more information regarding important details such as transaction timing, contract terms and deal certainty. Mr. Ford challenged the Board of Directors’ views as to the appropriate valuation of CSI and suggested that Abbott would, instead, rescind its current proposal and continue to monitor our performance. In the course of the discussion, Messrs. Ward and Ford discussed how to bridge the gap between respective views of the parties on valuation. Mr. Ford asked whether the Board of Directors would view $22.00 per Share as an acceptable basis for proceeding with discussions. Mr. Ward replied that, while he was not authorized to speak on behalf of the Board of Directors, he believed that such a price would likely be in a range that the Board of Directors would find to be an acceptable basis for proceeding with discussions. Mr. Ford communicated that he would consider the higher price with his team. On this day, our Shares closed on Nasdaq at $13.48 per Share.

On December 7, 2022, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward, Points and Rosenstein, and representatives of J.P. Morgan and Dorsey. The Dorsey representatives provided the Transaction Committee with an overview of fiduciary duties under Delaware law and process considerations relating to strategic transactions. Mr. Ward informed the Transaction Committee of his conversation with Mr. Ford the previous day. The Transaction Committee discussed risks and potential benefits to CSI’s stockholders relating to pursuing a transaction with Abbott, and agreed that in addition to price, speed to and certainty of closing were extremely important factors in considering whether to pursue such a transaction given the significant potential for negotiations over, or the pendency of, an acquisition transaction causing material disruptions to CSI’s ability to manage its business. While neither the Board of Directors nor the Transaction Committee had determined that CSI was then for sale, the Transaction Committee believed that it would be contrary to CSI’s interests to lose the opportunity to evaluate the value to our stockholders that was presented by Abbott’s proposal, if an acceptable agreement could be reached.

On December 7, 2022, in preparation for a potential due diligence process, we executed an agreement for a virtual data room. We began adding documents to the data room shortly thereafter and continued to do so throughout the transaction process.

On December 14, 2022, an executive from one of the similarly sized peer companies referenced above requested a meeting with Mr. Ward at an upcoming conference to discuss further a potential future combination of the two companies. Mr. Ward replied that we would not be attending this conference, but that we were willing to continue our earlier discussions and would await their proposal. This party did not respond prior to the announcement of the Merger Agreement.

On December 15, 2022, we executed the engagement letter with J.P. Morgan.

On December 16, 2022, Mr. Ward held a meeting at Party A’s offices with Party A, which appeared to still be in the very early stages of its business analysis. At the conclusion of the meeting, Party A communicated that it would require additional time to evaluate the opportunity. In the course of the meeting with Party A, it appeared to Mr. Ward that Party A’s expectations for the cash flow our business could generate to support our ongoing business while continuing to invest in our future pipeline were not achievable.

On December 20, 2022, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward, Points and Rosenstein, and representatives of J.P. Morgan and Dorsey. Mr. Ward reported that there had been no further communications from Abbott since December 6, 2022. The Transaction Committee discussed whether to reach out to Abbott for an update and whether to reach out to other parties who may be interested in an acquisition of CSI, given the pending proposal from Abbott and recent lack of communications from Abbott. Given that several parties had approached us in the last few years with potential interest in acquiring CSI, but none had followed with a firm proposal or even additional discussions following the initial meetings, with some expressly withdrawing from discussions and others remaining silent following initial inquiries, the Transaction Committee did not believe that there were any parties likely to be interested in acquisition discussions with us at this time at a valuation that the Board of Directors would consider. The Transaction Committee also believed, based on Abbott’s previous statements, that approaches to other parties at this time might also jeopardize the discussions with Abbott, which the Transaction Committee determined would not be in the best interest of us or our stockholders. While the Transaction Committee affirmed that CSI continued not to be for sale, it also believed that, even if Abbott would not increase its $20.00 offer, such offer was in a range sufficient for us to engage in negotiations with Abbott to potentially reach an agreement that would be advantageous to our stockholders; this belief was bolstered by our stock price performance and the business, operational and financing challenges we expected to face in the coming years. The Transaction Committee directed Mr. Ward to contact Mr. Ford for an update. On this day, our Shares closed on Nasdaq at $14.73 per Share.

On December 21, 2022, Mr. Ward called Mr. Ford. Mr. Ford informed Mr. Ward that Abbott spent more time analyzing the potential value for CSI. He concluded that the proposed purchase price of $20.00 per Share was Abbott’s best offer and that it could not justify paying a higher price. Mr. Ford noted the significant headwinds in our business, including the lack of growth in our core business and the uncertain reimbursement environment, which, in Abbott’s view, offset the potential value of our product development pipeline. Mr. Ford informed Mr. Ward that Abbott had stopped work internally on the proposed transaction, but confirmed that the $20.00 price per Share remained an open proposal. They discussed a potential transaction process, including the due diligence process, our need for closing certainty, and potential timing to reach an agreement if the Board of Directors agreed to proceed. Mr. Ward noted that the Board of Directors had a regular meeting scheduled for January 25, 2023. After discussion, they agreed that it would be unlikely that an acquisition agreement could be negotiated in time for consideration by the Board of Directors at that meeting. However, they believed that a signing date of February 3, 2023 could be possible. Mr. Ford said that he would meet with his staff and reconsider Abbott’s position based upon this conversation. Mr. Ward promptly informed the members of the Transaction Committee of Abbott’s position.

On December 24, 2022, Mr. Ford called Mr. Ward and informed him that Abbott would like to proceed with a transaction based upon the parameters discussed on December 21, 2022, and would attempt to work to reach an agreement by February 3, 2023.

On December 26, 2022, Abbott sent Mr. Ward an updated letter containing Abbott’s non-binding indication of interest to acquire CSI for a purchase price of $20.00 per Share in cash, using Abbott’s available funds or existing borrowing capacity. Abbott’s letter indicated areas of focus for Abbott’s due diligence process and indicated a target date to execute a definitive agreement and announce a transaction of February 3, 2023.

The same day, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward and Points and representatives of J.P. Morgan and Dorsey. The Transaction Committee discussed the communications between Messrs. Ward and Ford to date and Abbott’s new proposal letter. The Transaction Committee unanimously approved moving forward with negotiating and executing a confidentiality agreement with Abbott and, once the confidentiality agreement was signed by both parties, permitting Abbott to engage in due diligence for the purpose of investigating a potential acquisition by Abbott of CSI. The Transaction Committee noted that it was not, at this time, recommending to the Board of Directors any definitive action with respect to a sale of CSI. Following this meeting, Mr. Ward informed Mr. Ford that we agreed to proceed with due diligence and commence negotiations.

Also on that day, Messrs. Ward and Points held a meeting with representatives of Abbott to discuss the proposed due diligence process, and Abbott sent a draft of the proposed confidentiality agreement. Over the next two days, the parties negotiated the terms of the confidentiality agreement, and the parties executed the confidentiality agreement on December 28, 2022. Neither the confidentiality agreement nor the December 26, 2022 letter from Abbott included an exclusivity provision or other restrictions on our ability to engage in strategic discussions with other parties. Later that day, we provided access to representatives of Abbott to our virtual data room. Throughout the negotiation process, access to the virtual data room was provided to additional representatives of and advisors to Abbott, and Abbott submitted due diligence questions and document requests, which CSI addressed during the negotiation process.

On December 29, 2022, the Board of Directors held a meeting by video conference at which Mr. Ward and the members of the Transaction Committee informed the Board of Directors of the events since the last Board of Directors meeting. After discussion, the Board of Directors agreed with the course of action as approved by the Transaction Committee and commenced by CSI management.

On December 30, 2022, Mr. Ward received an unsolicited message from an executive at another company in the medical technology industry, referred to in this proxy statement as “Party B.” The executive informed Mr. Ward that he would be introducing Mr. Ward by email to the head of corporate development and strategy at Party B, which email arrived on January 2, 2023. Party B was one of the five parties referenced above that had previously expressed an interest in CSI and requested a meeting. That meeting was held on September 15, 2021. From that meeting until December 30, 2022, however, Party B had not followed up with any messages, requests for information or updates.

On January 3, 2023, Mr. Ward received an email from Party B’s head of corporate development and strategy, proposing a meeting to include the Chief Executive Officer of Party B. On that same day, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward and Rosenstein and a representative of Dorsey. The Transaction Committee agreed that Mr. Ward should meet with Party B to better understand its intentions. The Transaction Committee also determined that J.P. Morgan should separately contact Party B. On January 4, 2023, at the direction of the Transaction Committee, a representative of J.P. Morgan spoke with the head of corporate development and strategy at Party B, who confirmed that Party B had an interest in acquiring CSI but did not appear to be prepared to make an offer imminently. J.P. Morgan informed this executive that, if Party B had an interest in acquiring us, J.P. Morgan recommended that Party B act promptly.

On January 5, 2023, Mr. Ward held a video conference with the Chief Executive Officer and other executives of Party B. Mr. Ward presented non-confidential information regarding CSI and answered Party B’s questions. Party B confirmed its interest in a potential acquisition of CSI; Mr. Ward did not inform Party B of the discussions with Abbott, but noted that if Party B were interested in an acquisition, they would need to act promptly to submit a proposal in writing for the Board of Directors to consider.

On January 6, 2023, Mr. Ward held a meeting with Party A at Party A’s request. Party A informed Mr. Ward that it was withdrawing from further consideration of an acquisition of CSI. Party A further informed Mr. Ward that our planned investments in the product development pipeline would reduce Party A’s flexibility in improving our short-term profitability, which would limit Party A’s ability to finance and otherwise support an acquisition of CSI. Party A indicated that it might consider re-engaging in discussions with us in 12-to-18 months, when, in Party A’s view, our pipeline would have matured, with our pathway to profitability becoming more apparent.

On January 11, 2023, representatives of Abbott and CSI held a full day of multiple and concurrent management due diligence meetings by video conference, covering many aspects of our business. These meetings were followed by due diligence visits to our facilities in Minnesota and Texas by Abbott representatives on January 12, 16 and 17, 2023, which focused primarily on manufacturing, quality and research and development matters.

On January 13, 2023, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward, Points and Rosenstein, and representatives of Dorsey. Mr. Ward provided the Transaction Committee with updates on the process with Abbott and his meetings with Party A and Party B. The Transaction Committee discussed these developments, but took no action at such time.

On January 15, 2023, Baker & McKenzie LLP, Abbott’s outside legal counsel (“Baker”), sent an initial draft of the Merger Agreement to Dorsey. The initial draft of the Merger Agreement contained several terms relevant to the speed to and certainty of closing that were inconsistent with priorities established by the Transaction Committee for evaluation of a potential transaction. These terms included the definition of Material Adverse Effect (as defined in the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Representations and Warranties”), certain restrictions on the Board of Directors’ ability to consider alternative proposals, certain limitations imposed by operating covenants relating to the conduct of our business following signing of the Merger Agreement and prior to closing, provisions governing the regulatory approval process and the allocation of regulatory risk between the parties and the amount of a CSI Termination Fee. The parties revised and negotiated the Merger Agreement, including with respect to the terms described above, until the day the Merger Agreement was signed.

On January 19, 2023, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward, Points and Rosenstein, and representatives of Dorsey. Mr. Ward provided the Transaction Committee with updates on the due diligence process with Abbott and Dorsey provided a summary of key considerations relating to the Merger Agreement, including that it would expect to negotiate various terms, including the terms set forth in the preceding paragraph. The Transaction Committee discussed these developments, but took no action at such time.

On January 20, 2023, Party B contacted J.P. Morgan and indicated that it would not be in a position to proceed with a proposal to acquire CSI at such time, due to other strategic matters on which it was focusing.

On January 22, 2023, Dorsey sent comments on the Merger Agreement to Baker.

On January 24 and 25, 2023, the Board of Directors held a regularly scheduled meeting in Houston, Texas, portions of which were also attended by Messrs. Points and Rosenstein and representatives of J.P. Morgan and Dorsey. The primary purpose of the meeting was for the Board of Directors to review CSI management’s proposed five-year strategic plan, including the Strategic Plan Projections (as defined in the section of this proxy statement titled “The Merger—Financial Projections”). During this meeting, the Board of Directors also reviewed the current status of the negotiations with Abbott. It appeared that Abbott’s due diligence review was substantially complete and Abbott had not raised, and CSI management did not expect Abbott to raise, any significant due diligence concerns. Dorsey presented to the Board of Directors with respect to its fiduciary duties under Delaware law, and summarized the material open issues remaining with the Merger Agreement. The Board of Directors also reviewed our financial results for the second quarter of fiscal 2023, received presentations on our strategic plan from members of CSI management, reviewed various financing options that could be considered if the transaction with Abbott did not move forward, and reviewed the risks to the business and our prospects in the absence of a transaction with Abbott. The Board of Directors concluded that it was reasonable to expect our stock price would not appreciate meaningfully in the near term, given our performance (including CSI’s then-unreleased second quarter earnings results) and the continued headwinds and risks to our business. The Board of Directors therefore concluded that Abbott’s offer remained, in its judgment, an attractive potential option for maximizing value for our stockholders, compared to our prospects of continuing as an independent public company.

On January 26, 2023, Baker sent a revised draft of the Merger Agreement to Dorsey. The parties continued to negotiate the Merger Agreement.

On January 28, 2023, Dorsey sent Baker the initial draft of the disclosure letter to the Merger Agreement, which the parties continued to revise and negotiate until immediately prior to signing of the Merger Agreement.

On January 30, 2023, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward, Points and Rosenstein, and representatives of J.P. Morgan and Dorsey. Mr. Ward sought input from the Transaction Committee on key considerations relating to the Merger Agreement, including the definition of Material Adverse Effect, provisions relating to the Board of Directors’ fiduciary duties and ability to consider alternate proposals that may be received from third parties, the operating covenants relating to the conduct of our business following signing of the Merger Agreement and prior to closing, and regulatory-related provisions. Following input from J.P. Morgan, Dorsey and CSI management, the Transaction Committee agreed that we should engage on these issues and continue to negotiate for terms that improved the terms of the transaction for CSI and its stockholders. Following this meeting, CSI management and Dorsey continued to engage with Abbott and Baker on the open issues.

On January 30, 2023, Dorsey sent a revised draft of the Merger Agreement to Baker.

On February 2, 2023, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward, Points and Rosenstein. Mr. Ward provided an update on the negotiation process. The Transaction Committee discussed these developments, but took no action at this time.

On February 3, 2023, Mr. Ward called Mr. Ford to discuss the status of the negotiations. Mr. Ford affirmed Abbott’s continued interest in pursuing the transaction. They discussed a new target date of February 8, 2023 to sign and announce the transaction, assuming the parties could finalize negotiations and resolve the open issues on the Merger Agreement.

On February 4, 2023, Baker sent Dorsey a revised draft of the Merger Agreement.

Dorsey and Baker held a telephone conference on February 5, 2023 to discuss the open issues on the Merger Agreement.

Also on February 5, 2023, Mr. Ward held discussions with a representative of Abbott and conveyed to him that he would not recommend the transaction to the Transaction Committee or the Board of Directors unless Abbott made certain revisions to the Merger Agreement terms regarding the definition of Material Adverse Effect, regulatory matters and interim operating covenants.

On February 6, 2023, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward, Points and Rosenstein, and representatives of J.P. Morgan and Dorsey. After a briefing by CSI management and Dorsey, the Transaction Committee discussed the status of the negotiations and the material open issues remaining in the Merger Agreement. The Transaction Committee confirmed its support for the position taken by Mr. Ward with Abbott on February 5, 2023.

On February 7, 2023, Abbott informed Mr. Ward that it would be willing to make certain modifications. Following this discussion, Baker sent Dorsey a revised draft of the Merger Agreement. Abbott characterized this draft as the final version approved by Abbott. Later that day, the Transaction Committee held a meeting by video conference, which was also attended by Messrs. Ward, Points and Rosenstein, and representatives of J.P. Morgan and Dorsey. The Transaction Committee discussed the process to get to a final agreement. Following this meeting, Mr. Ward contacted a representative of Abbott and informed him that with one additional modification, the Merger Agreement would sufficiently address the concerns that he had raised in the February 5, 2023 discussions with Abbott.

On February 8, 2023, Baker sent Dorsey a revised draft of the Merger Agreement, which addressed CSI’s concern. Mr. Ward verbally informed Abbott that this version of the Merger Agreement was suitable to submit to the Board of Directors for consideration.

On the same day, the Transaction Committee, the Human Resources and Compensation Committee and the Board of Directors held meetings by video conference, which were attended by all Board of Directors members and were also attended by Messrs. Ward, Points and Rosenstein, and representatives of J.P. Morgan and Dorsey, to consider the Merger Agreement. The Dorsey representatives presented on the Board of Directors’ fiduciary duties and provided an overview of the Merger Agreement, including (i) key closing conditions, such as regulatory approval; (ii) restrictions on the conduct of our business between signing and closing; (iii) the treatment of equity awards; (iv) a “no-shop” restriction requiring CSI to cease all third-party negotiations or discussions and prohibiting CSI from further soliciting other acquisition proposals (subject to a “fiduciary out” for a superior proposal); (v) the definition of and conditions relating to a Material Adverse Effect; (vi) the

$26,500,000 CSI Termination Fee to be paid by CSI in connection with the termination of the Merger Agreement under certain specified circumstances related to a change in the recommendation of the Board of Directors, CSI’s entry into an agreement for a superior proposal or the breach of certain of CSI’s covenants under the Merger Agreement; and (vii) the $26,500,000 Abbott Termination Fee payable by Abbott in connection with the termination of the Merger Agreement under certain specified circumstances related to regulatory laws or due to the consummation of the Merger being permanently enjoined under regulatory laws. Representatives of Dorsey answered questions from members of the Board of Directors regarding the terms of the Merger Agreement. Representatives of J.P. Morgan delivered the February 8, 2023 oral opinion of J.P. Morgan to CSI’s Board of Directors, which was confirmed by delivery of a written opinion, dated as of February 8, 2023, to the effect that, as of such date and based upon and subject to the assumptions made, procedures followed, matters considered and limitations on the review undertaken by J.P. Morgan in preparing its opinion, the consideration to be paid to the holders of Shares in the Merger was fair, from a financial point of view, to the holders of Shares, as more fully described below in the section of this proxy statement titled “The Merger — Opinion of J.P. Morgan Securities LLC.” The full text of the written opinion of J.P. Morgan, dated as of February 8, 2023, which sets forth, among other things, the assumptions made, procedures followed, matters considered and limitations on the review undertaken by J.P. Morgan in preparing its opinion, is attached as Annex B to this proxy statement and is incorporated herein by reference. In addition, CSI management presented to the Board of Directors with respect to the negotiating history and reviewed with the Board of Directors a number of factors to consider with respect to whether to proceed with approving the transaction. During the Transaction Committee meeting that preceded the Board of Directors meeting, the Transaction Committee, after considering the foregoing presentations and matters, as well as its own prior considerations and deliberations with respect to, and participation in the oversight of negotiations regarding, the potential transaction with Abbott, unanimously recommended the approval by the full Board of Directors of the Merger Agreement and related transactions. After the presentations by Dorsey, J.P. Morgan and CSI management, and after receiving the recommendation of the Transaction Committee, the Board of Directors continued to discuss the potential transaction with Abbott, CSI’s various alternatives thereto and the reasons that the Board of Directors believed that the Merger, the Merger Agreement and the other transactions contemplated thereby were advisable and in the best interests of CSI and our stockholders. For more information concerning the recommendation of the Board of Directors, see the section of this proxy statement titled, “The Merger — Recommendation of CSI’s Board of Directors and Reasons for the Merger.” Following such discussion, and following the close of the U.S. stock markets, the Board of Directors unanimously (i) determined that the Merger Agreement, the Merger, and the other transactions contemplated by the Merger Agreement are fair to, advisable, and in the best interests of CSI and its stockholders, (ii) authorized and approved the execution, delivery and performance of the Merger Agreement by and on behalf of CSI, (iii) resolved to recommend the adoption of the Merger Agreement and the transactions contemplated by the Merger Agreement to the stockholders of CSI and (iv) directed that the Merger Agreement be submitted to the stockholders of CSI for adoption. The Board of Directors authorized our senior management to execute the final Merger Agreement with Abbott.

Following the Board of Directors meeting, CSI and Abbott executed the Merger Agreement. On this day, our Shares closed on Nasdaq at $13.31 per Share.

Later the same day, the parties issued a joint press release announcing the execution of the Merger Agreement, which we filed the next morning with a Current Report on Form 8-K.

After considering the various factors described below, the Board of Directors has unanimously: (i) determined that the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement are fair to, advisable and in the best interests of CSI and its stockholders; (ii) authorized and approved the execution, delivery and performance of the Merger Agreement by and on behalf of CSI; (iii) resolved to recommend the adoption of the Merger Agreement and the transactions contemplated by the Merger Agreement by the stockholders of CSI; and (iv) directed that the Merger Agreement be submitted to the stockholders of CSI for adoption.

The Board of Directors unanimously recommends that you vote: (1) “FOR” the adoption of the Merger Agreement; (2) “FOR” the approval, on an advisory (non-binding) basis, of the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

In evaluating the Merger Agreement and the transactions contemplated thereby, including the Merger, the Board of Directors consulted with our senior management and legal and financial advisors, and considered and analyzed a range of factors. In the course of reaching its determination to approve the terms of the Merger Agreement and the Merger and to recommend that our stockholders approve the terms of the Merger Agreement and the Merger, the Board of Directors considered numerous factors, including the following material factors and benefits, each of which the Board of Directors believed supported its unanimous determination and recommendation:

The Board of Directors also considered a variety of uncertainties, risks and other potentially negative factors in its deliberations concerning the Merger and the other transactions contemplated by the Merger Agreement, including the following:

The foregoing discussion of information and factors considered by the Board of Directors is not intended to be exhaustive. In light of the variety of factors considered in connection with its evaluation of the Merger, the Board of Directors did not find it practicable to, and did not, quantify or otherwise assign relative weights to the specific factors considered in reaching its determinations and recommendations. Moreover, each member of the Board of Directors applied his or her own personal business judgment to the process and may have given different weight to different factors.

The Board of Directors believed that, overall, the potential benefits of the Merger to the stockholders outweigh the risks of the Merger and provide more certain value to our stockholders.

While CSI has generally provided, on either a quarterly or annual basis, estimated ranges of certain expected financial results and operational metrics for the current or pending fiscal quarter or year in its regular earnings press releases and other investor materials, CSI does not, in the ordinary course, publicly disclose forecasts or internal projections as to future long-term performance or results of operations due to the inherent unpredictability of the underlying assumptions and projections. However, CSI management has, from time to time, prepared, and made public, high-level prospective financial information used in presentations to analysts and stockholders, most recently in connection with a “Capital Markets Day” event held on August 3, 2022. The prospective financial information used at the Capital Markets Day event was furnished on a Current Report on Form 8-K filed by CSI on August 3, 2022.

CSI management, at the direction of the Board of Directors, prepares non-public, unaudited, prospective financial information as part of an annual strategic planning process. In connection with the strategic planning process for the 2023 fiscal year, which occurred after the Capital Markets Day event held on August 3, 2022, CSI management prepared non-public, unaudited, prospective financial information for fiscal years 2023 through

2027 (the “Strategic Plan Projections”). CSI management presented the Strategic Plan Projections to the Board of Directors at meetings held on January 24-25, 2023. At these meetings, CSI management reviewed with the Board of Directors (a) the Strategic Plan Projections, (b) certain assumptions that were utilized to prepare the Strategic Plan Projections, including that such estimates had been reasonably prepared on bases reflecting the best currently available judgments of CSI management, and (c) the purpose for which such estimates were prepared by CSI management. Assumptions made by CSI management to prepare the Strategic Plan Projections include, among other things, innovative potential of new products, product development requirements, preclinical and clinical research requirements, regulatory requirements, commercial launch dates, market sizes, market penetration, market shares, competitive landscape, average selling prices, product costs, gross margins, regulatory approvals, timing of new geographic launches, and operating expense estimates.

The Strategic Plan Projections were also used by the Transaction Committee and Board of Directors in connection their evaluations of the Merger and strategic alternatives to the Merger, including at the meeting of the Board of Directors held on February 8, 2023. The Board of Directors directed J.P. Morgan to use and rely on the Strategic Plan Projections for purposes of providing financial analyses in connection with the Board of Directors’ evaluation of the Merger and strategic alternatives to the Merger. For more information, please see the section of this proxy statement titled “The Merger—Background of the Merger.”

The Strategic Plan Projections were not prepared with a view toward public disclosure or toward complying with U.S. generally accepted accounting principles (“GAAP”), nor were they prepared with a view toward compliance with the published guidelines of the SEC, or the guidelines established by the American Institute of Certified Public Accountants for preparation and presentation of projections of prospective financial information. The non-GAAP financial measures used in the Strategic Plan Projections were relied upon by the Transaction Committee and the Board of Directors in connection with their considerations of the Merger and the Merger Consideration. While CSI believes that such non-GAAP financial measures provide useful supplemental information in analyzing CSI’s financial results, there are limitations associated with the use of such financial measures. Such non-GAAP measures as used by CSI may not be directly comparable to similarly titled measures used by other companies and should not be considered in isolation from, or as a substitute for, financial information presented in accordance with GAAP. The SEC rules, which otherwise would require a reconciliation of a non-GAAP financial measure to a GAAP financial measure, do not apply to non-GAAP financial measures provided to a board of directors or financial advisors in connection with a proposed business combination transaction such as the Merger if the disclosure is included in a document such as this proxy statement. In addition, reconciliations of non-GAAP financial measures to a GAAP financial measure were not provided to or relied upon by the Transaction Committee, the Board of Directors or J.P. Morgan in connection with the Merger. Accordingly, CSI has not provided a reconciliation of the financial measures included in the Strategic Plan Projections to the relevant GAAP financial measures. The Strategic Plan Projections may differ from published analyst estimates and forecasts, and do not take into account any events or circumstances after the date they were prepared, including the announcement of the Merger and the other transactions contemplated by the Merger Agreement.

Adjusted EBITDA and unlevered free cash flow contained in the Strategic Plan Projections set forth below are each “non-GAAP financial measures,” which are financial performance measures that are not calculated in accordance with GAAP. These non-GAAP financial measures should not be viewed as a substitute for GAAP financial measures and may be different from non-GAAP financial measures used by other companies. Furthermore, there are limitations inherent in non-GAAP financial measures because they exclude charges and credits that are required to be included in a GAAP presentation. Accordingly, these non-GAAP financial measures should be considered together with, and not as an alternative to, financial measures prepared in accordance with GAAP.

The Strategic Plan Projections reflect estimates and assumptions made by CSI management with respect to general business, economic, competitive, and other market and financial conditions and other future events, all of which are difficult to predict and many of which are beyond CSI’s control. In particular, the Strategic Plan Projections, while presented with numerical specificity, necessarily were based on variables and assumptions that are inherently uncertain. Because the Strategic Plan Projections cover multiple years, by their nature, they become subject to greater uncertainty with each successive year and are unlikely to anticipate each circumstance that will have an effect on CSI’s business and its results of operations. None of CSI, Abbott or any of their respective affiliates, advisors or other representatives makes any representation to any stockholder regarding the

validity, reasonableness, accuracy or completeness of the Strategic Plan Projections or the ultimate performance of CSI relative to the Strategic Plan Projections. The inclusion of the Strategic Plan Projections in this proxy statement does not constitute an admission or representation of CSI that the Strategic Plan Projections or the information contained therein is material. Except as required by applicable law, neither CSI nor any of its affiliates intends to, and each of them disclaims any obligation to, update, correct or otherwise revise the Strategic Plan Projections if any or all of them have changed or change or otherwise have become, are or become inappropriate (even in the short term). These considerations should be taken into account if evaluating the Strategic Plan Projections, which were prepared as of an earlier date. The Strategic Plan Projections included in this document have been prepared by, and are the responsibility of, CSI management. PricewaterhouseCoopers LLP has not audited, reviewed, examined, compiled nor applied agreed-upon procedures with respect to the accompanying Strategic Plan Projections and, accordingly, PricewaterhouseCoopers LLP does not express an opinion or any other form of assurance with respect thereto. The PricewaterhouseCoopers LLP report incorporated by reference in this proxy statement relates to CSI’s previously issued financial statements. It does not extend to the Strategic Plan Projections and should not be read to do so.

The Strategic Plan Projections should be evaluated, if at all, in conjunction with the historical financial statements and other information regarding CSI in its public filings with the SEC. The Strategic Plan Projections were developed by CSI management on a standalone basis without giving effect to the Merger and the other transactions contemplated by the Merger Agreement, and, therefore, the Strategic Plan Projections do not give effect to the Merger or any changes to CSI’s operations or strategy that may be implemented after the consummation of the Merger, including any certain legal, advisory and other acquisition and integration-related costs incurred or expected to be incurred in connection with the Merger. Furthermore, the Strategic Plan Projections do not take into account the effect of any failure of the Merger and the other transactions contemplated by the Merger Agreement to be completed and should not be viewed as accurate or continuing in that context.

The Strategic Plan Projections further reflect in many respects the subjective judgment of CSI management and, therefore, are susceptible to multiple interpretations and periodic revisions based on actual experience and business developments. The inclusion of the Strategic Plan Projections should not be regarded as an indication that CSI or anyone who received the Strategic Plan Projections then considered, or now considers, the Strategic Plan Projections to be necessarily predictive of actual future events, and this information should not be relied upon as such. CSI’s management views the Strategic Plan Projections as being subject to inherent risks and uncertainties associated with such long-range projections.

The information and table set forth below are included solely to give the stockholders access to certain of the Strategic Plan Projections for the period from fiscal year 2023 through fiscal year 2027 that were made available to the Transaction Committee, the Board of Directors and J.P. Morgan and are not included in this proxy statement in order to influence any stockholder’s decision to vote with respect to the adoption of the Merger Agreement or for any other purpose:

Pursuant to an engagement letter, dated December 15, 2022, CSI retained J.P. Morgan as its financial advisor in connection with a possible acquisition of CSI by any third party, including the Merger.

At the meeting of the Board of Directors held on February 8, 2023, J.P. Morgan rendered its oral opinion to the Board of Directors that, as of such date and based upon and subject to the factors and assumptions set forth in its opinion, the consideration to be paid to the holders of Shares in the Merger was fair, from a financial point of view, to such stockholders. J.P. Morgan has confirmed its February 8, 2023 oral opinion by delivering its written opinion to the Board of Directors, dated February 8, 2023, that, as of such date, the consideration to be paid to the holders of Shares in the Merger was fair, from a financial point of view, to such stockholders.

The full text of the written opinion of J.P. Morgan dated February 8, 2023, which sets forth, among other things, the assumptions made, procedures followed, matters considered and limitations on the review undertaken by J.P. Morgan in preparing its opinion, is attached as Annex B to this proxy statement and is incorporated herein by reference. The summary of the opinion of J.P. Morgan set forth in this proxy statement is qualified in its entirety by reference to the full text of such opinion. CSI stockholders are urged to read the full text of the written opinion in its entirety. J.P. Morgan’s opinion was addressed to the Board of Directors (in its capacity as such) in connection with and for the purposes of its evaluation of the Merger, and was directed only to the consideration to be paid to the holders of Shares in the Merger and did not address any other aspect of the Merger. J.P. Morgan expressed no opinion as to the fairness of the consideration paid in connection with the Merger to the holders of any other class of securities, creditors or other constituencies of CSI or as to the underlying decision by CSI to engage in the Merger. The issuance of J.P. Morgan’s opinion was approved by a fairness committee of J.P. Morgan. The summary of the opinion of J.P. Morgan set forth in this proxy statement is qualified in its entirety by reference to the full text of such opinion. The opinion does not constitute a recommendation to any stockholder of CSI as to how such stockholder should vote with respect to the Merger or any other matter.

In arriving at its opinion, J.P. Morgan, among other things:

In addition, J.P. Morgan held discussions with certain members of CSI management with respect to certain aspects of the Merger, and the past and current business operations of CSI, the financial condition and future prospects and operations of CSI and certain other matters J.P. Morgan believed necessary or appropriate to its inquiry.

In giving its opinion, J.P. Morgan relied upon and assumed the accuracy and completeness of all information that was publicly available or was furnished to or discussed with J.P. Morgan by CSI or otherwise reviewed by or for J.P. Morgan, and J.P. Morgan did not independently verify any such information or its accuracy or completeness, and pursuant to its engagement letter with CSI, J.P. Morgan did not assume any obligation to undertake any such independent verification. J.P. Morgan did not conduct and was not provided with any valuation or appraisal of any assets or liabilities, nor did J.P. Morgan evaluate the solvency of CSI or Abbott under any state or federal laws relating to bankruptcy, insolvency or similar matters. In relying on financial analyses and forecasts provided to J.P. Morgan or derived therefrom, J.P. Morgan assumed that they were

reasonably prepared based on assumptions reflecting the best currently available estimates and judgments by CSI management as to the expected future results of operations and financial condition of CSI to which such analyses or forecasts relate. J.P. Morgan expressed no view as to such analyses or forecasts or the assumptions on which they were based. J.P. Morgan also assumed that the Merger and the other transactions contemplated by the Merger Agreement will be consummated as described in the Merger Agreement. J.P. Morgan also assumed that the representations and warranties made by CSI and Abbott in the Merger Agreement and the related agreements were and will be true and correct in all respects material to its analysis. J.P. Morgan is not a legal, regulatory or tax expert and relied on the assessments made by advisors to CSI with respect to such issues. J.P. Morgan further assumed that all material governmental, regulatory or other consents and approvals necessary for the consummation of the Merger will be obtained without any adverse effect on CSI or on the contemplated benefits of the Merger.

The projections furnished to J.P. Morgan were prepared by CSI management as discussed more fully in the section of this proxy statement titled “The Merger — Financial Projections.” CSI does not publicly disclose internal CSI management projections of the type provided to J.P. Morgan in connection with J.P. Morgan’s analysis of the Merger, and such projections were not prepared with a view toward public disclosure. These projections were based on numerous variables and assumptions that are inherently uncertain and may be beyond the control of CSI management, including, without limitation, factors related to general economic and competitive conditions and prevailing interest rates. Accordingly, actual results could vary significantly from those set forth in such projections. For more information regarding the use of projections and other forward-looking statements, please refer to the section of this proxy statement titled “Legal and Cautionary Disclosures— Forward-Looking Statements.”

J.P. Morgan’s opinion was necessarily based on economic, market and other conditions as in effect on, and the information made available to J.P. Morgan as of, the date of such opinion. J.P. Morgan’s opinion noted that subsequent developments may affect J.P. Morgan’s opinion, and that J.P. Morgan does not have any obligation to update, revise, or reaffirm such opinion. J.P. Morgan’s opinion is limited to the fairness, from a financial point of view, of the consideration to be paid to the holders of Shares in the Merger, and J.P. Morgan has expressed no opinion as to the fairness of any consideration paid in connection with the Merger to the holders of any other class of securities, creditors or other constituencies of CSI or as to the underlying decision by CSI to engage in the Merger. Furthermore, J.P. Morgan has expressed no opinion with respect to the amount or nature of any compensation to any officers, directors, or employees of any party to the Merger, or any class of such persons relative to the consideration to be paid to the holders of Shares in the Merger or with respect to the fairness of any such compensation.

We note that J.P. Morgan was not authorized to and did not solicit any expressions of interest from any other parties with respect to the sale of all or any part of CSI or any other alternative transaction.

The terms of the Merger Agreement, including the consideration to be paid to the holders of Shares, were determined through arm’s length negotiations between CSI and Abbott, and the decision to enter into the Merger Agreement was solely that of the Board of Directors. J.P. Morgan’s opinion and financial analyses were only one of the many factors considered by the Board of Directors in its evaluation of the Merger and should not be viewed as determinative of the views of the Board of Directors or CSI management with respect to the Merger or the consideration, including with respect to the consideration to be paid to the holders of Shares.

In accordance with customary investment banking practice, J.P. Morgan employed generally accepted valuation methodologies in rendering its opinion to the Board of Directors on February 8, 2023, and contained in the financial analyses presented to the Board of Directors on such date in connection with the rendering of such opinion. The following is a summary of the material financial analysis utilized by J.P. Morgan in connection with rendering its opinion to the Board of Directors and does not purport to be a complete description of the analyses or data presented by J.P. Morgan. Considering the data set forth below without considering the full narrative description of the financial analyses, including the methodologies and assumptions underlying the analyses, could create a misleading or incomplete view of J.P. Morgan’s analyses.

Public Trading Multiples. Using publicly available information, J.P. Morgan compared selected financial data of CSI with similar data for selected publicly traded companies engaged in businesses which J.P. Morgan judged to be sufficiently analogous to those engaged in by CSI. The companies selected by J.P. Morgan were as follows:

These companies were selected, among other reasons, because they are publicly traded companies with operations and businesses that, for the purposes of J.P. Morgan’s analysis, may be considered similar to those of CSI. However, certain of these companies may have characteristics that are materially different from those of CSI. The analyses necessarily involve complex considerations and judgments concerning differences in financial and operational characteristics of the companies involved and other factors that could affect the selected companies differently than they would affect CSI.

Using publicly available information, J.P. Morgan calculated the multiple of the firm value (the “FV”) for the selected companies (calculated as equity value, plus or minus, as applicable, net debt or net cash) to the analyst consensus estimates of calendar year 2023 revenues for the applicable company (the “FV/2023E Revenue Multiple”).

Based on the above analysis, J.P. Morgan selected a FV/2023E Revenue Multiple reference range for CSI of 1.7x to 3.4x. J.P. Morgan then applied such reference range to the projected revenue for calendar year 2023 provided in the Strategic Plan Projections. The analysis indicated a range of implied equity value per Share (rounded to the nearest $0.25) of approximately $13.75 to $24.75, which J.P. Morgan compared to the Merger Consideration of $20.00 per Share.

Selected Transaction Multiples Analysis. Using publicly available information, J.P. Morgan examined selected transactions involving businesses which J.P. Morgan judged to be analogous to the business (or aspects thereof) based on J.P. Morgan’s experience and familiarity with the industries in which CSI operates. The following transactions were selected by J.P. Morgan as relevant to the evaluation of the Merger:

None of the selected transactions reviewed was identical to the Merger. However, the selected transactions were chosen because certain aspects of the transactions, for purposes of J.P. Morgan’s analysis, may be considered sufficiently similar to the Merger. The analyses necessarily involve complex considerations and judgments concerning differences in financial and operational characteristic of the companies involved and other factors that could affect the transactions differently than they would affect the Merger.

Using publicly available information, J.P. Morgan calculated, for each selected transaction, the multiple of the target company’s FV implied in the relevant transaction to the target company’s revenue for the twelve-month period after the announcement (the “NTM”) of the applicable transaction (the “FV/NTM Revenue Multiple”).

Based on the above analysis, J.P. Morgan selected a FV/NTM Revenue Multiple reference range of 2.5x to 4.5x for CSI. J.P. Morgan then applied such reference range to the projected revenue for the twelve-month period ending December 31, 2023. The analysis indicated a range of implied equity values per Share (rounded to the nearest $0.25) of $19.00 to $31.75, which J.P. Morgan compared to the Merger Consideration of $20.00 per Share.

Discounted Cash Flow Analysis. J.P. Morgan conducted a discounted cash flow analysis for the purpose of determining an implied fully diluted equity value per Share. J.P. Morgan calculated the unlevered free cash flows that CSI is expected to generate during fiscal years 2023 through 2027 based upon the Strategic Plan Projections, which were discussed with and approved by CSI management for use by J.P. Morgan in connection with its financial analyses, which was then adjusted, at the direction of CSI management, for an assumed future financing by CSI of $100 million in gross proceeds in 2023 by adding the net proceeds of such assumed future financing to the unlevered free cash flows for 2023 and adjusting for the potential dilutive impact of such assumed future financing. J.P. Morgan also calculated a range of terminal values for CSI at the end of this period by applying perpetual growth rates ranging from 3.0% to 4.0%, based on guidance provided by CSI management, to estimates of the unlevered free cash flow of CSI during the fiscal year 2027, as provided in the Strategic Plan Projections. J.P. Morgan then discounted the unlevered free cash flow estimates and the range of terminal values to present value as of December 31, 2022 using discount rates from 10.5% to 12.5%, which were chosen by J.P. Morgan based upon an analysis of the weighted average cost of capital of CSI. The present value of the unlevered free cash flows and the range of terminal values were then adjusted by adding net cash and present value of net operating losses as of December 31, 2022. This analysis indicated a range of implied equity values for CSI, which J.P. Morgan divided by the number of outstanding Shares, calculated on a fully diluted basis and, at the direction of CSI management, adjusted for an assumed future financing by CSI of $100 million in gross proceeds in 2023, to derive a range of implied equity values per Share (rounded to the nearest $0.25) of $17.00 to $25.00, which J.P. Morgan compared to the Merger Consideration of $20.00 per Share.

Miscellaneous. The foregoing summary of certain material financial analyses does not purport to be a complete description of the analyses or data presented by J.P. Morgan. The preparation of a fairness opinion is a complex process and is not necessarily susceptible to partial analysis or summary description. J.P. Morgan believes that the foregoing summary and its analyses must be considered as a whole and that selecting portions of the foregoing summary and these analyses, without considering all of its analyses as a whole, could create an incomplete view of the processes underlying the analyses and its opinion. As a result, the ranges of valuations resulting from any particular analysis or combination of analyses described above were merely utilized to create points of reference for analytical purposes and should not be taken to be the view of J.P. Morgan with respect to the actual value of CSI. The order of analyses described does not represent the relative importance or weight given to those analyses by J.P. Morgan. In arriving at its opinion, J.P. Morgan did not attribute any particular weight to any analyses or factors considered by it and did not form an opinion as to whether any individual analysis or factor (positive or negative), considered in isolation, supported or failed to support its opinion. Rather, J.P. Morgan considered the totality of the factors and analyses performed in determining its opinion.

Analyses based upon forecasts of future results are inherently uncertain, as they are subject to numerous factors or events beyond the control of the parties and their advisors. Accordingly, forecasts and analyses used or made by J.P. Morgan are not necessarily indicative of actual future results, which may be significantly more or less favorable than suggested by those analyses. Moreover, J.P. Morgan’s analyses are not and do not purport to be appraisals or otherwise reflective of the prices at which businesses actually could be acquired or sold. None of the selected companies reviewed as described in the above summary is identical to CSI, and none of the selected transactions reviewed was identical to the Merger. However, the companies selected were chosen because they are publicly traded companies with operations and businesses that, for purposes of J.P. Morgan’s analysis, may be considered similar to those of CSI. The transactions selected were similarly chosen because their participants, size and other factors, for purposes of J.P. Morgan’s analysis, may be considered similar to the Merger. The analyses necessarily involve complex considerations and judgments concerning differences in financial and operational characteristics of the companies involved and other factors that could affect the companies compared to CSI and the transactions compared to the Merger.

As a part of its investment banking business, J.P. Morgan and its affiliates are continually engaged in the valuation of businesses and their securities in connection with mergers and acquisitions, investments for passive and control purposes, negotiated underwritings, secondary distributions of listed and unlisted securities, private placements, and valuations for corporate and other purposes. J.P. Morgan was selected to advise CSI with respect to the Merger and deliver an opinion to the Board of Directors with respect to the Merger on the basis of, among other things, such experience and its qualifications and reputation in connection with such matters and its familiarity with CSI and the industries in which it operates.

For financial advisory services rendered in connection with the Merger, CSI has agreed to pay J.P. Morgan an estimated fee of approximately $15.5 million, $2 million of which became payable to J.P. Morgan at the time J.P. Morgan delivered its opinion, and the remainder of which is contingent and payable upon the consummation of the Merger. In addition, CSI has agreed to reimburse J.P. Morgan for certain of its expenses incurred in connection with its services, including the fees and expenses of counsel, and will indemnify J.P. Morgan against certain liabilities arising out of J.P. Morgan’s engagement.

During the two years preceding the date of J.P. Morgan’s opinion, neither J.P. Morgan nor its affiliates have had any other material financial advisory or other material commercial or investment banking relationships with CSI. During the two years preceding the date of J.P. Morgan’s opinion, J.P. Morgan and its affiliates have had and continue to have commercial or investment banking relationships with Abbott for which J.P. Morgan and such affiliates have received customary compensation. J.P. Morgan’s commercial banking affiliate is an agent bank and a lender under outstanding credit facilities of Abbott, for which it receives customary compensation or other financial benefits. During the two-year period preceding delivery of its opinion ending on February 8, 2023, the aggregate fees recognized by J.P. Morgan from Abbott were approximately $2,460,000. In addition, J.P. Morgan and its affiliates hold, on a proprietary basis, less than 1% of the outstanding common stock of each of CSI and Abbott. In the ordinary course of their businesses, J.P. Morgan and its affiliates may actively trade the debt and equity securities or financial instruments (including derivatives, bank loans or other obligations) of CSI or Abbott for their own accounts or for the accounts of customers and, accordingly, they may at any time hold long or short positions in such securities or other financial instruments.

When considering the recommendation of the Board of Directors that you vote to approve the proposal to adopt the Merger Agreement, you should be aware that some of our directors and executive officers may have interests in the Merger that are different from, or in addition to, the interests of stockholders more generally, as more fully described below. The Board of Directors was aware of and considered these interests, among other matters, to the extent that they existed at the time, in reaching the determination that the Merger Agreement, the Merger, and the other transactions contemplated by the Merger Agreement were fair to, advisable, and in the best interests of CSI and its stockholders, in reaching its decision to authorize and approve the execution, delivery and performance of the Merger Agreement by and on behalf of CSI, in making its recommendation to adopt the Merger Agreement and the transactions contemplated by the Merger Agreement by the stockholders of CSI, and in directing that the Merger Agreement be submitted to the stockholders for adoption.

As of the date of this proxy statement, none of our directors or executive officers has entered into any agreement with Abbott regarding employment with, or compensation to be received from, Abbott or the surviving corporation on a going-forward basis following the consummation of the Merger, and there have been no discussions of any such arrangements between Abbott and any of our directors or executive officers. Prior to and following the Closing, however, certain of our executive officers may have discussions, and following the Closing, may enter into agreements with Abbott or the surviving corporation, or their respective affiliates regarding employment with, or the right to purchase or participate in the equity of, Abbott, the surviving corporation or one or more of their affiliates.

From and after the Effective Time, the surviving corporation will (1)(A) indemnify and hold harmless each Indemnified Person (as defined in the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Indemnification and Insurance”) against any costs and expenses (including reasonable attorneys’ fees), judgments, fines, losses, claims, damages, penalties, amounts, or liabilities incurred or paid in connection with any investigation, claim, action, inquiry, suit, proceeding, or judgment, based on, arising out of, relating to or in connection with the fact that such person is or was an Indemnified Person and arising out of or relating to acts or omissions occurring or existing (or alleged to have occurred or extend) at, prior to, or after the Effective Time (including in respect of acts or omissions in connection with the Merger Agreement and the transactions contemplated by the Merger Agreement), (B) exculpate and release from any lability such Indemnified Persons, and (C) provide the advancement of expenses to such Indemnified Persons, in each case to the same extent such Indemnified Persons are so indemnified and held harmless, exculpated and released, or have the right to the

advancement of expenses as of the Signing Date pursuant to CSI’s certificate of incorporation or bylaws or indemnification contracts between CSI and the Indemnified Persons in existence on January 1, 2023, and (2) maintain, for six years after the Effective Time, policies of directors’ and officers’ liability insurance and fiduciary liability insurance that cover each person covered by CSI’s current directors’ and officers’ liability insurance and fiduciary liability insurance policies as of January 1, 2023 and that provide for at least the same coverage and amounts as, and contain terms and conditions which are no less favorable to the insured as, the current policies with respect to claims arising from facts or events that occurred on or before the Effective Time. Abbott will not be required to expend more than the Maximum Annual Premium (as defined in the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Indemnification and Insurance”) for such insurance. In lieu of maintaining the insurance coverage described above, Abbott may direct CSI or the surviving corporation to purchase, at Abbott’s expense, “tail” insurance coverage, at a cost no greater than the Maximum Annual Premium, that provides insurance coverage no less favorable than the coverage described above.

For more information, please see the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Indemnification and Insurance.”

As of March 14, 2023, (i) 42,198,048 Shares were issued and outstanding, including 2,330,163 Restricted Shares, of which 1,223,849 were subject to time-based vesting and 1,106,314 were subject to performance-based vesting; and (ii) 345,089 Shares were reserved for issuance pursuant to outstanding CSI equity awards under CSI’s stock plans, consisting of (A) 65,432 Shares reserved for issuance pursuant to outstanding CSI Options, with a weighted average exercise price of $36.75 per Share, and (B) 279,657 Shares reserved for issuance pursuant to outstanding CSI RSUs. The CSI Options and Restricted Shares held by CSI’s executive officers and the CSI RSUs held by the directors, in each case, as of immediately prior to the Effective Time, will be treated as described below.

The Merger Agreement provides that at the Effective Time, each:

For more information, please see the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Merger Consideration—Treatment of CSI Options, Restricted Shares, and CSI RSUs.”

The following is a description of the potential contractual payments that CSI may have to pay to its executive officers in connection with the Merger, including the acceleration of benefits in the event of a qualifying termination of an executive officer as provided in an employment agreement with such executive officer or pursuant to a benefit plan offered by CSI.

Notwithstanding the treatment of CSI equity awards in connection with a change in control provided in any employment agreement or other benefit plan offered by CSI as described below, upon the occurrence of the Effective Time, all such CSI equity awards will be treated in accordance with the terms of the Merger Agreement. For more information, please see the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Merger Consideration—Treatment of CSI Options, Restricted Shares, and CSI RSUs.”

CSI maintains the Cardiovascular Systems, Inc. Executive Officer Severance Plan, as amended and restated on August 22, 2018 (the “Severance Plan”), which provides for a limited number of covered employees, including our executive officers, to receive the following benefits if their employment is terminated by CSI (or its successor) without “cause” or due to a “reduction in force” or by the executive officer for “good reason” (as such terms are defined in the Severance Plan), within 24 months following a change of control of CSI (which will occur upon the consummation of the Merger):

In addition, the Severance Plan provides that if an executive officer’s employment is terminated by CSI without cause or due to a reduction in force, in either such case, that does not occur within 24 months following a change of control of CSI, then the executive officer will receive the same benefits as described above, except that the severance pay will be limited to annual base salary payable over the Severance Period (and would not include the target bonus component).

The Severance Period applicable to each executive officer is based on such executive officer’s title, and is set forth in the table below.

The estimated aggregate amount of the cash benefits our executive officers would receive upon a qualifying termination of employment under the Severance Plan, assuming the Merger closes on May 31, 2023, and a qualifying termination of employment of such executive officer occurs immediately thereafter, is approximately $9.0 million, which amount does not include any amounts to be received by our executive officers in exchange for the CSI Options, Restricted Shares, or CSI RSUs held by them that are unvested and are being accelerated, cancelled and converted into the right to receive consideration in the Merger (as described in the section of this proxy statement titled “The Merger—Interests of CSI’s Directors and Executive Officers in the

Merger—Treatment of CSI Options, Restricted Shares and CSI RSUs”), as such acceleration, cancellation and conversion will occur pursuant to the terms of the Merger Agreement prior to any termination of employment, and not the Severance Plan. For estimates of the amounts of such cash severance that each of our named executive officers may be entitled to receive under the Severance Plan individually, please see the section of this proxy statement titled “The Merger—Interests of CSI’s Directors and Executive Officers in the Merger—Golden Parachute Compensation.”

In addition to the named executive officers, Stephen Rempe, our Chief Human Resources Officer, may be entitled to receive $961,223 of cash severance under the Severance Plan, which is comprised of $470,453 (equal to 1.5 times Mr. Rempe’s annual base salary), plus $282,272 (equal to 1.5 times the target annual bonus Mr. Rempe is eligible to earn under CSI’s cash bonus plan for fiscal year 2023), plus $172,498 (equal to a pro-rated payment of Mr. Rempe’s annual performance bonus for fiscal 2023), plus $36,000 (equal to the estimated cost of subsidized continued healthcare coverage under COBRA (“COBRA Coverage”) to which Mr. Rempe may become entitled to under the Severance Plan, which represents the CSI-paid portion of COBRA Coverage for the maximum possible period and assumes actual benefit elections made by Mr. Rempe for the 2023 calendar year, and premiums for such year, continue unchanged for the benefit period), in each case, based on the same assumptions set forth in the section of this proxy statement titled “The Merger—Interests of CSI’s Directors and Executive Officers in the Merger—Quantification of Potential Payments to Certain CSI Executive Officers in Connection with the Merger” and applicable to the table set forth in the section of this proxy statement titled “The Merger—Interests of CSI’s Directors and Executive Officers in the Merger—Golden Parachute Compensation.” The estimated amount of cash severance to be received by Mr. Rempe upon a qualifying termination under the Severance Plan does not include any amounts to be received by him in exchange for the Restricted Shares held by him that are unvested and being accelerated, cancelled and converted into the right to receive consideration in the Merger (as described under “The Merger—Interests of CSI’s Directors and Executive Officers in the Merger—Treatment of CSI Options, Restricted Shares and CSI RSUs”), as such acceleration, cancellation and conversion will occur pursuant to the terms of the Merger Agreement prior to a termination of employment, and not the Severance Plan.

As a condition to receipt of the severance payments and benefits described above, each executive officer is required to execute a release of claims agreement in favor of CSI and to continue to comply with certain post-termination covenants in favor of CSI.

The Severance Plan does not affect any other rights our executive officers may have to severance benefits in their employment agreements. However, an executive officer will be eligible for severance benefits under the Severance Plan only to the extent the severance is not duplicative of the benefits received by the executive officer under his or her employment agreement. The executive officer will receive benefits under his or her employment agreement first, and then will be eligible for severance benefits under the Severance Plan; provided, that the combined benefit will not exceed the maximum benefit available under the Severance Plan.

The Employment Agreement, effective August 16, 2016, by and between Scott Ward and CSI (the “Ward Employment Agreement”), provides that if Mr. Ward’s employment is terminated without “cause” or if he resigns for “good reason” (as such terms are defined in the Ward Employment Agreement) within 24 months following a change of control of CSI (which will occur upon the consummation of the Merger), he will be entitled to receive:

As a condition to receipt of the severance payments and benefits described above, Mr. Ward is required to execute a release of claims agreement in favor of CSI and to continue to comply with certain post-termination covenants in favor of CSI.

The Severance Plan provides that an executive officer participating in the Severance Plan is eligible to receive the greater of the severance benefits provided under the Severance Plan or a severance agreement between CSI and such officer, but that such executive officer may not receive duplicative severance benefits.

The Employment Agreement, effective February 7, 2018, by and between Jeffrey Points and CSI (the “Points Employment Agreement”), provides that if Mr. Points’ employment is terminated without “cause” or if he resigns for “good reason” (as such terms are defined in the Points Employment Agreement) within 24 months following a change of control of CSI (which will occur upon the consummation of the Merger), he will be entitled to receive:

As a condition to receipt of the severance payments and benefits described above, Mr. Points is required to execute a release of claims agreement in favor of CSI and to continue to comply with certain post-termination covenants in favor of CSI.

The Severance Plan provides that an executive officer participating in the Severance Plan is eligible to receive the greater of the severance benefits provided under the Severance Plan or a severance agreement between CSI and such officer, but that such executive officer may not receive duplicative severance benefits.

CSI entered into employment agreements with Alexander Rosenstein, Sandra Sedo, and Stephen Rempe on August 19, 2014, June 13, 2016, and March 20, 2019, respectively. The employment agreements were in CSI’s standard form for employees and are terminable by either party at any time for any reason. The employment agreements contain standard confidentiality, noncompetition and assignment of inventions provisions. The employment agreements do not provide the respective executive officer with any benefits, including bonuses or severance benefits, in connection with the Merger.

In recognition of the extraordinary performance of certain employees during the negotiation of the Merger Agreement, and in recognition of the need for such employee’s managerial skills in the operation of CSI between the Signing Date and the Closing Date, the Human Resources and Compensation Committee of the Board of Directors determined that it was in the best interests of CSI and its stockholders to pay a one-time cash bonus to such employees (each, a “Transaction Bonus”). The Transaction Bonuses will be paid to the recipients as soon as practicable following the Closing or on May 1, 2023, whichever occurs first; provided, however, that the payment of any Transaction Bonus is subject to such recipient’s continued employment with CSI through the date on which the Transaction Bonuses are actually paid.

The estimated aggregate amount of the Transaction Bonuses to be paid to our executive officers and other eligible employees is $750,000. For the amounts of the Transaction Bonus that each of our named executive

officers is eligible to receive individually, please see the section of this proxy statement titled “The Merger—Interests of CSI’s Directors and Executive Officers in the Merger—Golden Parachute Compensation.” In addition to the named executive officers, Mr. Rempe is eligible to receive a Transaction Bonus in the amount of $80,000.

In accordance with Item 402(t) of Regulation S-K, the table below sets forth the estimated compensation that is based on or otherwise relates to the Merger that will or may become payable to CSI’s named executive officers in connection with the Merger. For more information regarding certain elements of this compensation, please see the section of this proxy statement titled “The Merger—Interests of CSI’s Directors and Executive Officers in the Merger—Potential Contractual Payments to Executive Officers in Connection with the Merger”.

The table below assumes that:

The amounts shown in the table below do not include the value of payments or benefits that would have been earned, or any amounts associated with CSI equity awards that would vest pursuant to their terms, on or prior to Closing, or the value of payments or benefits that are not based on, or otherwise related to, the Merger.

In addition to the assumptions described in the preceding paragraph, the amounts set forth in the table below are based on certain other assumptions that are described in the footnotes accompanying the table below. These assumptions may or may not actually be correct. Accordingly, the ultimate amounts to be received by a named executive officer in connection with the Merger may differ from the amounts set forth below. For purposes of the footnotes to the table below, “double-trigger” refers to benefits that require two conditions, which are the occurrence of the Effective Time and a qualifying termination of the named executive officer.

Certain of the agreements for Restricted Shares provide that the total number of Shares issued to an executive officer pursuant to such agreements will be limited if, in the event of a change of control of CSI, the accelerated vesting of the underlying Shares would result in an “excess parachute payment” (as defined in Section 280G of the Code) to the executive officer for purposes of Section 280G of the Code (taking into account all other rights, payments and benefits to which the executive officer is entitled under any other plan or agreement). Furthermore, while CSI may be permitted to take certain actions to reduce the amount of any potential “excess parachute payments” for “disqualified individuals” (as defined in Section 280G of the Code), as of the date of this proxy statement, none of CSI, the Board of Directors, or the Human Resources and Compensation Committee has approved any specific actions to mitigate the anticipated impact of Section 280G of the Code on CSI or any disqualified individuals.

As discussed above in the section of this proxy statement titled “The Merger—Interests of CSI’s Directors and Officers in the Merger—Treatment of CSI Options, Restricted Shares, and CSI RSUs,” at the Effective Time, each CSI Option, Restricted Share, and CSI RSU will be accelerated (to the extent unvested) and (i) in the case of in-the-money CSI Options and CSI RSUs, will cancelled and automatically converted into the right to receive an amount in cash equal to the product of (A) the aggregate number of Shares subject to such CSI equity award, and (B) the Merger Consideration (less, with respect to each CSI Option, the per Share exercise price) and (ii) in the case of the Restricted Shares, will be treated as a Share in the Merger.

The following table sets forth the number of Shares and the number of Shares underlying outstanding CSI equity awards held by each of CSI’s executive officers, including our named executive officers and former executive officers who were employed by CSI during CSI’s fiscal year ended June 30, 2022, and non-employee directors, including a former director who sat on the Board of Directors during CSI’s fiscal year ended June 30, 2022 and the current fiscal year, as of March 14, 2023. The table also sets forth the values of these Shares and CSI equity awards, determined as the number of Shares (or Shares subject to the CSI equity awards) multiplied by the Merger Consideration. None of the executive officers, named executive officers, or non-employee directors hold any CSI Options, whether vested or unvested. Except for the interests described herein, no additional Shares or CSI equity awards have been or are expected to be issued or granted, as applicable, to any executive officer, named executive officer, or non-employee director in contemplation of the Merger.

If the Merger is consummated and certain conditions are met, stockholders (i) who continuously hold Shares through the Effective Time, (ii) who did not vote their Shares in favor of the adoption of the Merger Agreement, (iii) who are entitled to demand appraisal rights under Section 262 of the DGCL, (iv) who otherwise properly comply with the applicable requirements and procedures of Section 262 of the DGCL and (v) who do not thereafter withdraw their demand for appraisal of such Shares, fail to perfect or otherwise lose their appraisal rights, in each case in accordance with Section 262 of the DGCL, will be entitled to demand appraisal of their Shares and receive, if the Merger is successful and the Merger is consummated, in lieu of the Merger Consideration, an amount in cash equal to the “fair value” of their Shares (as of the Effective Time, exclusive of any element of value arising from the accomplishment or expectation of the Merger, together with interest, if any), as determined by the Delaware Court of Chancery, in accordance with Section 262 of the DGCL. Stockholders should be aware that the fair value of their Shares could be more than, the same as or less than the Merger Consideration and that an investment banking opinion as to the fairness, from a financial point of view, of the consideration payable in a sale transaction, such as the Merger, is not an opinion as to, and does not otherwise address, fair value under Section 262 of the DGCL. Any stockholder contemplating the exercise of such appraisal rights should review carefully the provisions of Section 262 of the DGCL, particularly the procedural steps required to properly demand and perfect such rights.

The following is a summary of the procedures to be followed by stockholders who wish to exercise their appraisal rights under Section 262 of the DGCL. A copy of the full text of the version of Section 262 of the DGCL applicable to the Merger Agreement is attached to this proxy as Annex C. This summary does not purport to be a complete statement of, and is qualified in its entirety by reference to, Section 262 of the DGCL. All references in Section 262 of the DGCL and in this summary to a “stockholder” are to the record holder of Shares as to which appraisal rights are asserted. A person holding a beneficial interest in Shares held of record in the name of another person, such as a broker or nominee, must act promptly

to cause the stockholder of record to follow the steps summarized below properly and in a timely manner to perfect appraisal rights. Failure to timely and fully comply with the procedures of Section 262 of the DGCL may result in the loss of appraisal rights under Section 262 of the DGCL. Stockholders should assume that CSI will take no action to perfect any appraisal rights of any stockholder.

Any stockholder who desires to exercise his, her or its appraisal rights should review carefully Section 262 of the DGCL and is urged to consult his, her or its legal advisor before electing or attempting to exercise such rights. The following summary does not constitute any legal or other advice nor does it constitute a recommendation that the stockholders exercise appraisal rights under Section 262 of the DGCL.

Under Section 262 of the DGCL, where a merger agreement is to be submitted for adoption at a meeting of the stockholders, the corporation, not less than 20 days prior to the meeting, shall notify each of the stockholders who was such on the record date for notice of such meeting with respect to shares for which appraisal rights are available under Section 262 of the DGCL that appraisal rights are available for any or all shares of such class or series of stock of such constituent corporation, and shall include in such notice a copy of Section 262 of the DGCL. This proxy statement constitutes the formal notice of appraisal rights under Section 262 of the DGCL, and the required copy of Section 262 of the DGCL is attached to this proxy statement as Annex C. Any stockholder who wishes to exercise such appraisal rights or who wishes to preserve his, her or its right to do so should review the following discussion and Annex C carefully because failure to timely and properly comply with the procedures specified may result in the loss of appraisal rights under the DGCL.

If a stockholder elects to exercise appraisal rights under Section 262 of the DGCL, such stockholder must do all of the following:

Within 10 days after the effective date of the Merger, the surviving corporation will provide notice of the effective date of the Merger to those stockholders who have properly made a written demand for appraisal pursuant to the first bullet above, as required by Section 262 of the DGCL, has not voted in favor of the adoption of the Merger Agreement and has not withdrawn or otherwise lost the right to appraisal. If the Merger is consummated, a failure to make a written demand for appraisal in accordance with the time periods specified in the first bullet above (or to take any of the other steps specified in the above bullets) will be deemed to be a waiver or a termination of your appraisal rights. At any time within 60 days after the effective date of the Merger, any stockholder who has demanded an appraisal, but who has not commenced an appraisal proceeding or joined that proceeding as a named party, has the right to withdraw the demand and to accept the Merger Consideration, specified by the Merger Agreement for his, her or its Shares. Any attempt to withdraw made more than 60 days after the effective date of the Merger will require the written approval of the surviving corporation and no appraisal proceeding before the Delaware Court of Chancery as to any stockholder will be dismissed without the approval of the Delaware Court of Chancery. Such approval may be conditioned upon any terms the Delaware Court of Chancery deems just; provided, however, that this provision will not affect the right of any

stockholder that has made an appraisal demand but who has not commenced an appraisal proceeding or joined such proceeding as a named party to withdraw such stockholder’s demand for appraisal and to accept the terms offered in the Merger within 60 days after the effective date of the Merger. If the surviving corporation does not approve a stockholder’s request to withdraw a demand for appraisal when the approval is required or if the Delaware Court of Chancery does not approve the dismissal of an appraisal proceeding, the stockholder would be entitled to receive only the appraised value determined in any such appraisal proceeding. This value could be higher or lower than, or the same as, the value of the Merger Consideration.

All written demands for appraisal should be addressed to Cardiovascular Systems, Inc., Attention: Secretary, 1225 Old Highway 8 NW, St. Paul, Minnesota 55112. The demand for appraisal must be executed by or for the stockholder of record, fully and correctly, as such stockholder’s name appears on the stockholder’s Shares (whether in book entry or on physical certificates). If the Shares are owned of record in a fiduciary capacity, such as by a trustee, guardian or custodian, the demand should be made in that capacity, and if the Shares are owned of record by more than one person, as in a joint tenancy or tenancy in common, the demand must be made by or for all owners of record. An authorized agent, including one or more joint owners, may execute the demand for appraisal for a stockholder of record, but such agent must identify the record owner or owners and expressly disclose in such demand that the agent is acting as agent for the record owner or owners of such Shares.

A beneficial owner of Shares held in “street name” who wishes to exercise appraisal rights should take such actions as may be necessary to ensure that a timely and proper demand for appraisal is made by the stockholder of record. If Shares are held through a broker, bank or other nominee who in turn holds the Shares through a central securities depository nominee, a demand for appraisal of such Shares must be made by or on behalf of the depository nominee, and must identify the depository nominee as the stockholder of record. Any beneficial owner who wishes to exercise appraisal rights and holds Shares through a nominee holder is responsible for ensuring that the demand for appraisal is timely made by the stockholder of record. The beneficial holder of the Shares should instruct the nominee holder that the demand for appraisal should be made by the stockholder of record of the Shares, which may be a central securities depository nominee if the Shares have been so deposited.

A record stockholder, such as a broker, bank, fiduciary, depository or other nominee, who holds Shares as a nominee for several beneficial owners may exercise appraisal rights with respect to the Shares held for one or more beneficial owners while not exercising such rights with respect to the Shares held for other beneficial owners. In such case, the written demand for appraisal must set forth the number of Shares covered by such demand. Unless a demand for appraisal specifies a number of Shares, such demand will be presumed to cover all Shares held in the name of such stockholder.

Within 120 days after the effective date of the Merger, the surviving corporation or any stockholder who has complied with Section 262 of the DGCL and is entitled to appraisal rights under Section 262 of the DGCL may commence an appraisal proceeding by filing a petition in the Delaware Court of Chancery demanding a determination of the fair value of the Shares held by all stockholders entitled to appraisal rights who did not vote their Shares in favor of the Merger and properly demanded appraisal of such Shares. If no such petition is filed within that 120-day period, appraisal rights will be lost for all stockholders who had previously demanded appraisal of their Shares. None of Abbott, Merger Sub or CSI, as the surviving corporation, has any obligation to or has any present intention to file a petition and stockholders should not assume that any of the foregoing parties will file a petition or will initiate any negotiations with respect to the fair value of the Shares.

Accordingly, it is the obligation of the stockholders to initiate all necessary action to perfect their appraisal rights in respect of the Shares within the period prescribed in Section 262 of the DGCL.

Within 120 days after the effective date of the Merger, any stockholder who has complied with Section 262 of the DGCL and the requirements for exercise of appraisal rights will be entitled, upon written request, to receive from the surviving corporation a statement setting forth the aggregate number of Shares not voted in favor of the adoption of the Merger Agreement and with respect to which CSI has received demands for appraisal, and the aggregate number of stockholders of such Shares. Such statement must be mailed within 10 days after a written request therefor has been received by the surviving corporation or within 10 days after

the expiration of the period for delivery of demands for appraisal, whichever is later. Notwithstanding the foregoing requirement that a demand for appraisal must be made by or on behalf of the record owner of the Shares, a person who is the beneficial owner of Shares held either in a voting trust or by a nominee on behalf of such person, and as to which demand has been properly made and not effectively withdrawn, may, in such person’s own name, file a petition for appraisal or request from the surviving corporation the statement described in this paragraph.

If a petition for appraisal is duly filed by any stockholder and a copy of the petition is delivered to the surviving corporation, the surviving corporation will then be obligated within 20 days after receiving service of a copy of the petition to file with the Delaware Register in Chancery a duly verified list (the “Verified List”) containing the names and addresses of all stockholders who have demanded an appraisal for their Shares (the “Dissenting Stockholders”) and with whom agreements as to the value of their Shares has not been reached. Upon the filing of a petition by a Dissenting Stockholder, the Delaware Court of Chancery may order a hearing and that notice of the time and place fixed for the hearing on the petition will be mailed to the surviving corporation and all the Dissenting Stockholders shown on the Verified List. Notice will also be published at least one week before the day of the hearing in a newspaper of general circulation published in the City of Wilmington, Delaware, or in another publication deemed advisable by the Delaware Court of Chancery. The costs relating to these notices will be borne by the surviving corporation.

If a hearing on the petition is held, the Delaware Court of Chancery is empowered to determine which Dissenting Stockholders have complied with the provisions of Section 262 of the DGCL and are entitled to an appraisal of their Shares. The Delaware Court of Chancery may require that Dissenting Stockholders submit their stock certificates, if any, to the Delaware Register in Chancery for notation thereon of the pendency of the appraisal proceedings. The Delaware Court of Chancery is empowered to dismiss the proceedings as to any Dissenting Stockholder who does not comply with such requirement. Accordingly, Dissenting Stockholders are cautioned to retain their stock certificates after the Effective Time and thereafter comply with all orders of the Delaware Court of Chancery in respect of such certificates. In addition, assuming the Shares remain listed on a national securities exchange immediately before the Effective Time, which we expect to be the case, the Delaware Court of Chancery is required to dismiss the appraisal proceedings as to all Dissenting Stockholders unless (i) the total number of Shares entitled to appraisal exceeds 1% of the outstanding Shares eligible for appraisal or (ii) the value of the consideration provided in the Merger for such total number of Shares exceeds $1 million.

After the Delaware Court of Chancery determines which stockholders are entitled to appraisal, the appraisal proceeding will be conducted in accordance with the rules of the Delaware Court of Chancery, including any rules specifically governing appraisal proceedings. Through the appraisal proceeding, the Delaware Court of Chancery will determine the fair value of the Shares exclusive of any element of value arising from the accomplishment or expectation of the Merger, together with interest, if any, to be paid upon the amount determined to be the fair value. Unless the Delaware Court of Chancery in its discretion determines otherwise for good cause shown, interest from the effective date of the Merger through the date of payment of the judgment will be compounded quarterly and will accrue at 5% over the Federal Reserve discount rate (including any surcharge) as established from time to time during the period between the effective date of the Merger and the date of payment of the judgment. However, at any time before the entry of judgment in the proceedings, the surviving corporation may pay to each stockholder entitled to appraisal an amount in cash, in which case interest will accrue thereafter only upon the sum of (i) the difference, if any, between the amount so paid by the surviving corporation and the fair value of the Shares as determined by the Delaware Court of Chancery, and (ii) interest accrued before such voluntary cash payment, unless paid at that time.

In determining fair value, the Delaware Court of Chancery is to take into account all relevant factors. In Weinberger v. UOP, Inc., the Supreme Court of Delaware discussed the factors that could be considered in determining fair value in an appraisal proceeding, stating that “proof of value by any techniques or methods that are generally considered acceptable in the financial community and otherwise admissible in court” should be considered, and that “fair price obviously requires consideration of all relevant factors involving the value of a company.” The Delaware Supreme Court stated that, in making this determination of fair value, the Delaware Court of Chancery must consider market value, asset value, dividends, earnings prospects, the nature of the enterprise and any other facts that could be ascertained as of the date of the merger that throw any light on

future prospects of the merged corporation. In Weinberger, the Supreme Court of Delaware also stated that “elements of future value, including the nature of the enterprise, which are known or susceptible of proof as of the date of the merger and not the product of speculation, may be considered.” Section 262 of the DGCL provides that fair value is to be “exclusive of any element of value arising from the accomplishment or expectation of the merger.” In Cede & Co. v. Technicolor, Inc., the Delaware Supreme Court stated that such exclusion is a “narrow exclusion that does not encompass known elements of value,” but which rather applies only to the speculative elements of value arising from such accomplishment or expectation. An opinion of an investment banking firm as to the fairness from a financial point of view of the consideration payable in a merger is not an opinion as to fair value under Section 262 of the DGCL. You should be aware that the fair value of your Shares as determined under Section 262 of the DGCL could be more than, the same as, or less than the Merger Consideration that you would otherwise be entitled to receive under the terms of the Merger Agreement.

Upon application by the surviving corporation or by any stockholder entitled to participate in the appraisal proceeding, the Delaware Court of Chancery may, in its discretion, proceed to trial upon the appraisal prior to the final determination of the stockholders entitled to an appraisal. Any stockholder whose name appears on the Verified List and who has submitted such stockholder’s stock certificates, if any, to the Delaware Register in Chancery, if such is required, may participate fully in all proceedings until it is finally determined that such stockholder is not entitled to appraisal rights. When the fair value of the Shares is determined, the Delaware Court of Chancery will direct the payment of such value, with interest thereon, if any, to the stockholders entitled thereto, forthwith in the case of holders of uncertificated stock or upon surrender to the corporation of the certificates representing such Shares in the case of certificated stock. The Delaware Court of Chancery’s decree may be enforced as other decrees in the Delaware Court of Chancery may be enforced. The Delaware Court of Chancery may also (i) determine the costs of the proceeding (which do not include attorneys’ fees or the fees and expenses of experts) and tax such costs upon the parties as the Delaware Court of Chancery deems equitable and (ii) upon application of a stockholder, order all or a portion of the expenses incurred by any Dissenting Stockholder in connection with the appraisal proceeding, including, without limitation, reasonable attorneys’ fees and fees and expenses of experts, to be charged pro rata against the value of all the Shares entitled to appraisal. In the absence of such an order, each party bears its own expenses. Determinations by the Delaware Court of Chancery are subject to appellate review by the Delaware Supreme Court.

Stockholders considering whether to seek appraisal should bear in mind that the fair value of their Shares determined under Section 262 of the DGCL could be more than, the same as, or less than the value of the Merger Consideration to be paid in the Merger. Although CSI believes that the Merger Consideration is fair, no representation is made as to the outcome of the appraisal of fair value as determined by the Delaware Court of Chancery. Neither Abbott nor CSI anticipates offering more than the Merger Consideration to any Dissenting Stockholder, and each of Abbott and CSI reserve the right to assert, in any appraisal proceeding, that for purposes of Section 262 of the DGCL, the “fair value” of the Shares is less than the Merger Consideration.

The process of exercising appraisal rights requires compliance with technical prerequisites. Stockholders wishing to exercise their appraisal rights should consult with their own legal counsel in connection with compliance with Section 262 of the DGCL.

Any stockholder who has duly demanded and perfected appraisal rights in compliance with Section 262 of the DGCL will not, after the effective date of the Merger, be entitled to vote his, her or its Shares for any purpose or be entitled to the payment of dividends or other distributions thereon, except dividends or other distributions payable to stockholders as of a date prior to the Effective Time.

If any stockholder who demands appraisal of Shares under Section 262 of the DGCL fails to perfect, successfully withdraws or loses such stockholder’s right to appraisal, such stockholder’s Shares will be deemed to have been converted at the Effective Time into the right to receive the Merger Consideration. A stockholder will fail to perfect, or effectively lose, the stockholder’s right to appraisal if no petition for appraisal is filed within 120 days after the effective date of the Merger. Inasmuch as CSI has no obligation to file such a petition and has no present intention to do so, any stockholder who desires such a petition is advised to file it on a timely basis. In addition, a stockholder who has not commenced an appraisal proceeding or joined that proceeding as a named party may withdraw his, her or its demand for appraisal in accordance with Section 262 of the DGCL and accept the Merger Consideration by delivering to CSI a written withdrawal of such stockholder’s demand for appraisal and acceptance of the terms of the Merger either within 60 days after the effective date of the Merger

or thereafter with the written approval of CSI. Notwithstanding the foregoing, no appraisal proceeding in the Delaware Court of Chancery will be dismissed as to any stockholder without the approval of the Delaware Court of Chancery, and such approval may be conditioned upon such terms as the Delaware Court of Chancery deems just; provided, however, that the limitation set forth in this sentence will not affect the right of any stockholder who has not commenced an appraisal proceeding or joined that proceeding as a named party to withdraw such stockholder’s demand for appraisal and to accept the Merger Consideration within 60 days after the effective date of the Merger.

STOCKHOLDERS WHO VOTE SHARES IN FAVOR OF THE ADOPTION OF THE MERGER AGREEMENT WILL NOT BE ENTITLED TO EXERCISE APPRAISAL RIGHTS WITH RESPECT THERETO BUT, RATHER, WILL RECEIVE THE MERGER CONSIDERATION.

The foregoing summary of the rights of the stockholders to seek appraisal rights under Delaware law does not purport to be a complete statement of the procedures to be followed by the stockholders desiring to exercise any appraisal rights available thereunder and is qualified in its entirety by reference to Section 262 of the DGCL. The proper exercise of appraisal rights requires strict adherence to the applicable provisions of the DGCL. A copy of the version of Section 262 of the DGCL applicable to the Merger Agreement is included as Annex C to this proxy statement.

The Merger will be accounted for as a “business combination” for financial accounting purposes.

The following discussion is a summary of certain material U.S. federal income tax consequences of the Merger that may be relevant to U.S. Holders and Non-U.S. Holders (each as defined below). This summary is general in nature and does not purport to be a complete analysis of all potential tax effects of the Merger. This discussion is based upon the Internal Revenue Code of 1986, as amended (the “Code”), Treasury Department regulations promulgated under the Code (the “Treasury Regulations”), published rulings and administrative pronouncements of the Internal Revenue Service (the “IRS”) and judicial decisions, all as in effect on the date of this proxy statement and all of which are subject to change or differing interpretations at any time, possibly with retroactive effect. This discussion is limited to stockholders who hold their Shares as “capital assets” within the meaning of Section 1221 of the Code (generally, property held for investment purposes).

This discussion is for general information only and does not address all of the U.S. federal income tax consequences that may be relevant to stockholders in light of their particular circumstances. For example, this discussion does not address the tax consequences that may be relevant to stockholders who may be subject to special treatment under U.S. federal income tax laws, such as:

If a partnership (including an entity or arrangement, domestic or non-U.S., treated as a partnership for U.S. federal income tax purposes) owns Shares, then the tax treatment of a partner in such partnership will generally depend upon the status of the partner and the activities of the partner and the partnership. Partnerships holding Shares and partners therein should consult their tax advisors regarding the consequences of the Merger.

In addition, this summary does not address (i) the tax consequences associated with the Merger under any U.S. federal non-income tax laws, including estate, gift and other tax laws, (ii) the tax considerations associated with the Merger under any state, local or non-U.S. tax laws, (iii) the impact of the alternative minimum tax, the Medicare contribution tax on net investment income, or the special tax accounting rules under Section 451(b) of the Code, (iv) the tax considerations associated with transactions effectuated before or subsequent to or concurrently with the Merger (whether or not any such transactions are consummated in connection with the Merger), including without limitation any transaction in which Shares are acquired, or (v) the tax consequences for holders of options, warrants or similar rights to acquire Shares.

We have not sought, and do not intend to seek, any ruling from the IRS with respect to the statements made and the conclusions reached in the following summary, and no assurance can be given that the IRS will agree with the views expressed herein, or that a court will not sustain any challenge by the IRS in the event of litigation.

IN VIEW OF THE FOREGOING AND BECAUSE THE FOLLOWING DISCUSSION IS INTENDED AS A GENERAL SUMMARY FOR INFORMATIONAL PURPOSES ONLY, WE URGE YOU TO CONSULT YOUR OWN TAX ADVISOR WITH RESPECT TO THE SPECIFIC TAX CONSEQUENCES TO YOU IN CONNECTION WITH THE MERGER IN LIGHT OF YOUR OWN PARTICULAR CIRCUMSTANCES, INCLUDING FEDERAL ESTATE, GIFT AND OTHER NON-INCOME TAX CONSEQUENCES, AND TAX CONSEQUENCES UNDER STATE, LOCAL OR NON-U.S. TAX LAWS, INCLUDING THE IMPACT OF ANY RECENT CHANGES IN U.S. TAX LAWS.

For purposes of this discussion, a “U.S. Holder” is a beneficial owner of Shares that is for U.S. federal income tax purposes:

For purposes of this discussion, a “Non-U.S. Holder” is a beneficial owner of Shares that is not a U.S. Holder nor an entity classified as a partnership for U.S. federal income tax purposes.

The receipt of cash by a U.S. Holder in exchange for Shares pursuant to the Merger will be a taxable transaction for U.S. federal income tax purposes. In general, such U.S. Holder’s gain or loss will be equal to the difference, if any, between the amount of cash received by such U.S. Holder and the U.S. Holder’s adjusted tax basis in the Shares surrendered pursuant to the Merger. Gain or loss must be determined separately for each block of Shares (that is, Shares acquired at the same cost in a single transaction). A U.S. Holder’s adjusted tax basis generally will equal the amount that such U.S. Holder paid for Shares. Such gain or loss will be capital gain or loss and will be long-term capital gain or loss if such U.S. Holder’s holding period in such Shares is more than one year at the time of the completion of the Merger. Long-term capital gains of non-corporate taxpayers, including individuals, are currently taxed at preferential U.S. federal income tax rates. The deductibility of capital losses is subject to limitations.

Subject to the discussions below regarding backup withholding and FATCA (as defined below), any gain realized by a Non-U.S. Holder pursuant to the Merger generally will not be subject to U.S. federal income tax unless:

Backup withholding (currently, at a rate of 24%) may apply to the proceeds received by a stockholder pursuant to the Merger. Backup withholding generally will not apply to (1) a U.S. Holder that furnishes a correct taxpayer identification number and certifies that the taxpayer identification number provided is correct and that such stockholder is not subject to backup withholding on IRS Form W-9 (or a substitute or successor form) or (2) a Non-U.S. Holder that (i) provides a certification of such stockholder’s foreign status on the appropriate series of IRS Form W-8 (or a substitute or successor form) or (ii) otherwise establishes an exemption from backup withholding. Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against the stockholder’s U.S. federal income tax liability, if any, provided that the required information is timely furnished to the IRS. If any amount is withheld under the backup withholding rules, stockholders should consult with their U.S. tax advisors regarding whether and how any refund, credit or other tax benefit might be received or recognized with respect to the amounts so withheld.

Sections 1471 through 1474 of the Code and the Treasury Regulations and administrative guidance promulgated thereunder (commonly known as “FATCA”), impose a U.S. federal withholding tax of thirty percent (30%) on certain payments made to a “foreign financial institution” (as specially defined under these rules) unless such institution enters into an agreement with the U.S. government to withhold on certain payments and to collect and provide to the U.S. tax authorities substantial information regarding certain U.S. account holders of such institution (which includes certain equity and debt holders of such institution, as well as certain account holders that are foreign entities with U.S. owners) or an exemption applies. FATCA also generally will impose a U.S. federal withholding tax of 30% on certain payments made to a non-financial foreign entity unless such entity provides the withholding agent with either a certification that it does not have any substantial direct or indirect U.S. owners or provides information regarding substantial direct and indirect U.S. owners of the entity. An applicable intergovernmental agreement between the U.S. and an applicable foreign country may modify these requirements. Under certain circumstances, a Non-U.S. Holder might be eligible for refunds or credits of such taxes. FATCA withholding currently applies to payments of dividends and other U.S. source income considered to be fixed or determinable annual or periodic income. The Treasury Department has released proposed regulations which, if finalized in their present form, would eliminate the federal withholding tax of 30% under FATCA applicable to the gross proceeds of a sale or other disposition of our common stock. In its preamble to such proposed regulations, the Treasury Department stated that taxpayers may generally rely on the proposed regulations until final regulations are issued.

Stockholders are encouraged to consult with their own tax advisors regarding the possible implications of FATCA on the disposition of common stock pursuant to the Merger.

The Merger is subject to the provisions of the HSR Act and cannot be completed until each of CSI and Abbott file a notification and report form with the DOJ and the FTC under the HSR Act and the waiting period under the HSR Act applicable to the Merger and the other transactions contemplated by the Merger Agreement (or any extension thereof including the expiration or termination of any timing agreement entered into with any governmental authority) has expired or been terminated. CSI and Abbott filed notification and report forms under the HSR Act with the DOJ and the FTC on March 13, 2023. Under the HSR Act, certain acquisitions may not be completed until information has been furnished to the DOJ and the FTC and the applicable HSR Act waiting period requirements have been satisfied. The waiting period under the HSR Act applicable to the Merger is 30 calendar days, unless the waiting period is terminated earlier (provided, however, that the FTC has temporarily suspended granting early termination other than in narrow circumstances that do not apply during the initial 30 day waiting period), extended by a request for additional information and documentary materials (which we refer to as a “Second Request”), or restarted if Abbott voluntarily withdraws and refiles, which commences a new 30 calendar day waiting period. If the DOJ or FTC issues a Second Request, the parties must observe a separate 30-day waiting period, which would begin to run only after both parties have substantially complied with such Second Request, unless the waiting period is terminated earlier or the parties agree to extend the waiting period (or commit not to consummate the transaction for a specified period of time).

At any time before or after consummation of the Merger, notwithstanding the termination or expiration of the waiting period under the HSR Act, the DOJ or the FTC could take such action under the antitrust laws as it deems necessary or desirable in the public interest, including seeking to enjoin the completion of the Merger, seeking divestiture of substantial assets of one or both of the parties, requiring the parties to license or hold separate assets or terminate existing relationships and contractual rights, or requiring the parties to agree to other remedies. At any time before or after the completion of the Merger, and notwithstanding the termination or expiration of the waiting period under the HSR Act, a governmental authority in any state or foreign jurisdiction could take such action under the antitrust laws or foreign investment laws as it deems necessary or desirable in the public interest. Such action may include seeking to enjoin the completion of the Merger, seeking divestiture of substantial assets of one or both of the parties, requiring the parties to license or hold separate assets or terminate existing relationships and contractual rights, or requiring the parties to agree to other remedies. Private parties may also seek to take legal action under the antitrust laws or foreign investment laws under certain circumstances, including by seeking to intervene in the regulatory process or litigate to enjoin or overturn regulatory approvals, any of which actions could significantly impede or even preclude obtaining required regulatory approvals. Any of the matters described in this paragraph could result in the imposition of a

Burdensome Condition (as defined in the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Regulatory Filings”), which may cause one or more of the conditions to the closing of the Merger not to be satisfied or give Abbott the right to terminate the Merger Agreement.

Although we expect that all required regulatory clearances and approvals will be obtained, we cannot assure you that these regulatory clearances and approvals will be timely obtained, obtained at all or that the granting of these regulatory clearances and approvals will not involve the imposition of additional conditions, restrictions, qualifications, requirements or limitations on the completion of the Merger, including the requirement to divest assets, license or hold separate assets or terminate existing relationships and contractual rights, or agree to other remedies, or require changes to the terms of the Merger Agreement, or that a challenge to the Merger on antitrust grounds or other regulatory grounds will not be made, or if such challenge is made, what the result will be. These conditions, changes or challenges could result in the imposition of a Burdensome Condition (as defined in the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Regulatory Filings”), the conditions to the Merger not being satisfied or Abbott terminating the Merger Agreement. There is currently no way to predict how long it will take to obtain all of the required regulatory approvals or whether such approvals will ultimately be obtained and there may be a substantial period of time between the approval of the proposal to adopt the Merger Agreement by the stockholders and the completion of the Merger.

CSI and Abbott have agreed to use reasonable best efforts to obtain all regulatory approvals required to consummate the Merger and the other transactions contemplated by the Merger Agreement, subject to certain limitations as set forth in the Merger Agreement, including the limitation that Abbott not be required to accept any Burdensome Condition (as defined in the section of this proxy statement titled “Proposal 1: Adoption of the Merger Agreement—Regulatory Filings”).

If the Merger is completed, the Shares will be delisted from Nasdaq and deregistered under the Exchange Act and Shares will no longer be publicly traded. As such, CSI will no longer file periodic reports under the Exchange Act with the SEC on account of CSI’s common stock.

As of March 23, 2023, a complaint has been filed in federal court by a purported stockholder related to the Merger. The complaint was filed on March 17, 2023, in the United States District Court for the Southern District of New York and is captioned O’Dell v. Cardiovascular Systems, Inc., et al., Case No. 1:23-cv-02293 (the “Complaint”). The Complaint names as defendants CSI and each member of the Board of Directors, which collectively with CSI, we refer to as the “CSI Defendants” in this proxy statement. The Complaint alleges violations of Section 14(a) of the Exchange Act against all CSI Defendants and alleges violations of Section 20(a) of the Exchange Act against the members of the Board of Directors in connection with the disclosures made by the CSI Defendants related to the Merger. The Complaint alleges that CSI’s preliminary proxy statement on Schedule 14A filed with the SEC on March 13, 2023 omitted or misrepresented material information therein. The Complaint seeks (i) injunctive relief preventing the consummation of the Merger, unless and until certain information, as requested in the Complaint, is disclosed, (ii) rescission of the Merger Agreement, to the extent already implemented, or rescissory damages, (iii) direction of the CSI Defendants to account to the plaintiff for all damages purportedly suffered by plaintiff as a result of the CSI Defendants’ alleged wrongdoing, (iv) an award of plaintiff’s costs and disbursements of the action, including reasonable attorneys’ and expert fees and expenses, and (v) such other and further equitable relief as the court may deem just and proper.

In addition, as of March 23, 2023, CSI has received four demand letters (the “Demand Letters”) from counsel to purported stockholders, which generally seek to have certain information allegedly omitted from the preliminary proxy statement on Schedule 14A filed with the SEC on March 13, 2023 be disclosed.

The CSI Defendants believe the allegations and claims asserted in the Complaint and the Demand Letters are without merit and that the disclosures in the preliminary proxy statement on Schedule 14A filed with the SEC on March 13, 2023, and this proxy statement comply fully with applicable law. We cannot predict the outcome of, or estimate the possible loss or range of loss from, these matters. It is possible that additional or similar complaints or demand letters may be filed against, or received by, CSI, the Board of Directors, or Abbott. If such additional complaints are filed or demand letters received, absent new or different allegations that are material, we will not necessarily announce such additional complaints or demand letters.

satisfaction or waiver (where permissible under the Merger Agreement or applicable law) of all of the conditions to Closing set forth in the Merger Agreement (other than those conditions that by their terms are to be satisfied at the Closing (subject to their satisfaction or waiver (where permissible))), unless another time, date or place is agreed to in writing by Abbott and CSI.

On the Closing Date, or on such other date as Abbott and CSI may agree to in writing, CSI will cause a certificate of merger to be executed and filed with the Secretary of State of the State of Delaware in such form as required by and in accordance with the DGCL. The Merger will become effective at the time the certificate of merger has been duly filed with the Secretary of State of the State of Delaware or such other later date and time as is agreed upon by Abbott and CSI and specified in the certificate of merger, such date and time are referred to as the “Effective Time.”

Each Share issued and outstanding immediately prior to the Effective Time, other than (i) Excluded Shares or (ii) Dissenting Shares, will be converted automatically into the right to receive the Merger Consideration, equal to $20.00 per Share, in cash, without interest.

The Merger Agreement provides that, at the Effective Time, subject to all applicable federal, state and local tax withholding requirements, each:

Any amounts payable to each employee holder of CSI Options, Restricted Shares or CSI RSUs will be paid pursuant to standard payroll procedures as soon as administratively practicable following the Effective Time. Any amounts payable to each non-employee holder of CSI Options, Restricted Shares or CSI RSUs will be paid by the paying agent upon surrender of the holder’s award documentation or certificate(s) previously representing Restricted Shares, as applicable.

Prior to the Effective Time, the Board of Directors (or the Human Resources and Compensation Committee) will adopt such resolutions as are necessary to give effect to the transactions described above.

The Board of Directors will adopt such resolutions and take any action reasonably necessary to terminate CSI’s stock plans, effective as of and contingent on the Effective Time. The Board of Directors will take any action necessary to ensure that after the Effective Time, Abbott and Merger Sub will not be required to issue any Shares or other stock pursuant to or in settlement of any CSI equity award.

As of the Signing Date, no new offering period will commence and no new employees are permitted to begin participating in the CSI Employee Stock Purchase Plan (“ESPP”). The Board of Directors will adopt such

resolutions and take any action reasonably necessary to terminate, no later than five business days prior to the Effective Time, any offering period under the ESPP and any amounts credited to the accounts of participants will be used to purchase Shares in accordance with the ESPP. Such Shares will be treated in the same way as all other Shares.

The Merger Agreement provides that at or prior to the Effective Time, Abbott will deposit with a bank or trust company reasonably acceptable to CSI, to act as paying agent for the benefit of the holders of the Shares and non-employee holders of CSI equity awards made under CSI’s stock plans, cash in an amount sufficient to pay the aggregate Merger Consideration required to be paid pursuant to the Merger Agreement. The fund established for the payment of the Merger Consideration will not be used for any other purpose.

Promptly after the Effective Time, the surviving corporation will instruct the paying agent to mail to each holder of record of Shares: (i) a letter of transmittal, which will specify that delivery will be effected, and risk of loss and title to the certificates previously representing certificated Shares (if any) (“Certificates”) will pass, only upon delivery of such Certificates (or effective affidavits of loss in lieu thereof) to the paying agent, and will otherwise be in customary form and have such other provisions as are reasonably acceptable to Abbott and CSI; and (ii) instructions for effecting the surrender of Certificates (or effective affidavits of loss in lieu thereof), or Shares in non-certificated book-entry form (“Book-Entry Shares”), in exchange for payment of the Merger Consideration. Promptly after the Effective Time, the surviving corporation will instruct the paying agent to mail to each non-employee holders of CSI equity awards made under CSI’s stock plans, instructions for use in effecting the surrender of such equity awards in exchange for payment. Upon surrender of Certificates (or effective affidavits of loss in lieu thereof) or Book-Entry Shares to the paying agent in accordance with the instructions in the letter of transmittal, as well as a duly completed and validly executed letter of transmittal the holder of such Certificates or Book-Entry Shares will be entitled to receive the Merger Consideration for each Share formerly represented by such Certificates or Book-Entry Shares. In addition, with respect to non-employee holders of CSI equity awards made under CSI’s stock plans, upon completion of the surrender of the applicable awards, the holders shall be entitled to receive Merger Consideration as set forth in the Merger Agreement. Any Certificates, Book-Entry Shares and awards surrendered will then be cancelled.

If payment of the Merger Consideration is to be made to a person other than the person in whose name any surrendered Certificate or Book-Entry Shares is registered, it will be a condition of such payment that the person requesting the payment will pay any transfer or other similar taxes requires by making cash payment to a person other than the registered holder of the surrendered Certificate or Book-Entry Shares or will establish to the satisfaction of the paying agent that such tax has been paid or is not applicable. If any portion of the Merger Consideration is to be registered in the name of a person other than the person whose name a surrendered Certificate or Book-Entry Share is registered, it is a condition to the registration that the surrendered Certificate and Book-Entry Share are properly endorsed or otherwise in proper form for transfer and that such person requesting the delivery of the Merger Consideration will pay the paying agent any transfer or similar taxes required as a result of such registration or establish to the satisfaction of the paying agent that such tax has been paid or is not applicable.

From and after the Effective Time, there will be no further registration of the transfer of Shares immediately outstanding prior to the Effective Time and the stock transfer books for those Shares shall be closed. From and after the Effective Time, until surrendered as contemplated by the Merger Agreement, each Certificate or Book-Entry Share represents only the right to receive the Merger Consideration as contemplated by the Merger Agreement. The surviving corporation will, however, be required to pay dividends or make any other distributions with a record date prior to the Effective Time and subject to the applicable holder’s surrender of Certificates or Book-Entry Shares. No interest will be paid or will accrue on any cash payable to holders of Certificates or Book-Entry Shares pursuant to the Merger Agreement. Abbott, Merger Sub, the surviving corporation and the paying agent are entitled to deduct and withhold from the Merger Consideration such amounts as they are required to deduct and withhold with respect to the Code or any provision of the tax law.

The Merger Agreement contains representations and warranties of CSI, Abbott, and Merger Sub.

Some of the representations and warranties in the Merger Agreement made by CSI are qualified as to “materiality” or a “Material Adverse Effect.” For purposes of the Merger Agreement, a “Material Adverse