EXHIBIT 2.1

                               AMENDMENT NO. 2 TO
                          AGREEMENT AND PLAN OF MERGER

     THIS AMENDMENT NO.  2 TO AGREEMENT AND PLAN OF MERGER (this "Amendment") is
entered into as of August 10, 2006, by and among ATS Medical, Inc., a Minnesota
corporation ("Parent"), Seabiscuit Acquisition Corp., a Delaware corporation and
a wholly-owned subsidiary of Parent ("Merger Subsidiary"), 3F Therapeutics,
Inc., a Delaware corporation (the "Company"), and Boyd D. Cox, as Stockholder
Representative (the "Stockholder Representative" and, together with Parent,
Merger Subsidiary and the Company, the "Parties").

                                    RECITALS

     WHEREAS, the Parties entered into that certain Agreement and Plan of Merger
dated January 23, 2006, which agreement was amended by the Parties on June 13,
2006 (the "Merger Agreement");

     WHEREAS, the Merger Agreement provides that, on or after August 31, 2006
(the "Termination Date"), and provided that certain conditions are met, any of
Parent, Merger Subsidiary or the Company may terminate the Merger Agreement and
abandon the transactions contemplated therein;

     WHEREAS, the Parties desire to amend the Merger Agreement in order to
extend the Termination Date as provided herein; and

     WHEREAS, the boards of directors of Parent, Merger Subsidiary and the
Company have approved this Amendment.

     NOW, THEREFORE, in consideration of the foregoing, and for other good and
valuable consideration, the receipt and adequacy of which are hereby
acknowledged, the Parties agree as follows:

                                   AGREEMENT

1.   DEFINITIONS.  Capitalized terms used herein and not otherwise defined
     herein shall have the meanings ascribed to such terms in the Merger
     Agreement.

2.   AMENDMENT.  Subsection (ddddddd) of Section 11.1 of the Merger Agreement is
     hereby amended and restated in its entirety as follows:

          "(ddddddd) "Termination Date" shall mean September 30, 2006."

3.   NO OTHER AMENDMENTS.  Except as specifically set forth in Section 2 of this
     Amendment, the Merger Agreement shall remain unchanged and shall continue
     in full force and effect.

4.   MISCELLANEOUS.

     (a) SUCCESSORS AND ASSIGNS.  The terms and conditions of this Amendment
         shall inure to the benefit of and be binding upon and be enforceable by
         the respective heirs, successors and assigns of the parties hereto.
         Nothing in this Amendment, express or implied, is intended to confer
         upon any party, other than the parties hereto or their respective
         successors and assigns, any rights, remedies, obligations or
         liabilities under or by reason of this Amendment, except as expressly
         provided in this Amendment.

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     (b) GOVERNING LAW.  This Amendment shall be governed by, construed and
         enforced in accordance with the internal laws of the State of Delaware
         (regardless of the laws that might otherwise govern under applicable
         principles of conflicts of law).

     (c) COUNTERPARTS.  This Amendment may be signed in any number of
         counterparts and the signatures delivered by facsimile, each of which
         shall be an original, with the same effect as if the signatures thereto
         and hereto were upon the same instrument. This Amendment shall become
         effective when each party hereto shall have received a counterpart
         hereof signed by the other parties hereto.

                  [Remainder of Page Intentionally Left Blank]

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     IN WITNESS WHEREOF, the Parties have caused this Amendment to be duly
executed by their respective authorized officers as of the day and year first
above written.

<Table>
                                            
PARENT:                                        ATS MEDICAL, INC.

                                               By: /s/ Michael D. Dale
                                               --------------------------------------------------------
                                                   Michael D. Dale
                                                   President and Chief Executive Officer

MERGER SUBSIDIARY:                             SEABISCUIT ACQUISITION CORP.

                                               By: /s/ Michael D. Dale
                                               --------------------------------------------------------
                                                   Michael D. Dale
                                                   Chief Executive Officer

COMPANY:                                       3F THERAPEUTICS, INC.

                                               By: /s/ Walter A. Cuevas
                                               --------------------------------------------------------
                                                   Walter A. Cuevas
                                                   President and Chief Executive Officer

STOCKHOLDER REPRESENTATIVE:                    /s/ Boyd D. Cox
                                               --------------------------------------------------------

                                               Boyd D. Cox
</Table>

                                 SIGNATURE PAGE
                AMENDMENT NO. 2 TO AGREEMENT AND PLAN OF MERGER

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