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                                                                 Exhibit 10.28.1



                     FIRST AMENDMENT TO EMPLOYMENT AGREEMENT


        This First Amendment to Employment Agreement (the "Amendment") is made
as of December 10, 1999, between Radiance Medical Systems, Inc., a Delaware
corporation (the "Company"), and Stephen R. Kroll, an individual ("Executive").

                                    RECITALS

        WHEREAS, the Company currently employs Executive pursuant to that
certain Employment Agreement dated February 1, 1999 (the "Employment
Agreement"); and

        WHEREAS, the Company and Executive desire to amend the Employment
Agreement to extend the automatic renewal terms set forth in the Employment
Agreement, as provided in greater detail below;

        NOW THEREFORE, in consideration of the mutual agreements and covenants
hereinafter set forth and for other valuable consideration, the Company and
Executive hereby agree as follows:

                                    AGREEMENT

        1.     DEFINITIONS.

        Unless otherwise defined herein, capitalized terms used herein shall
have the meanings assigned to them in the Employment Agreement.

        2.     AMENDMENT TO SECTION 2 OF THE EMPLOYMENT AGREEMENT.

        Section 2 of the Employment Agreement is hereby amended to read in its
entirety as follows:

               "2. TERM. The term of this Agreement will begin on February 1,
        1999 (the "Effective Date"), and shall continue thereafter for a two (2)
        year period, and commencing on the first anniversary of the Effective
        Date shall be extended on each day for one (1) day so that the remaining
        term hereof is always one (1) year unless either party elects to
        terminate this Agreement in accordance with its provisions. Executive's
        employment is subject to earlier termination as hereafter specified."

        3.     AMENDMENT TO SECTION 5.5.

        Section 5.5 of the Employment Agreement is hereby amended to read in its
entirety as follows:

               "5.5 PAYMENTS UPON REMOVAL OR TERMINATION. If during the term of
        this Agreement, the Executive resigns for one of the reasons stated in
        Section 5.3, or the Company terminates the Executive's service, except
        as provided in Sections 5.1 or 5.2 hereof, the Executive shall be
        entitled to the following compensation: (i) the portion of his then
        current Base Salary which has accrued through his date of termination,
        (ii) any payments for unused vacation and reimbursement expenses, which
        are due, accrued or payable at the date of Executive's termination,
        (iii) severance payment in an amount (the "Severance Amount") equal to
        Executive's


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        then-current Base Salary, payable for the remainder of the Term; and
        (iv) to the extent not already vested under Section 4.5 or otherwise all
        of Executive's options to purchase shares of the Company's common stock
        and restricted stock shall accelerate and automatically vest by one
        additional year, and such options shall otherwise be exercisable in
        accordance with their terms. In addition, in such event, Executive shall
        be entitled to (a) a prorated payment equal to the target bonus amount
        for which Executive would be eligible for the year in which such
        resignation or termination occurred, and (b) continuation of the
        insurance benefits set forth in Exhibit C and, to the extent
        permissible, participation in the Company's 401k plan, for the remainder
        of the Term."

        4.     MISCELLANEOUS.

               (a) Continuing Force and Effect. Except as herein expressly
amended, all terms, covenants and provisions of the Employment Agreement are and
shall remain in full force and effect and all references therein to such
Employment Agreement shall henceforth refer to the Employment Agreement as
amended by this Amendment. This Amendment shall be deemed incorporated into, and
a part of, the Employment Agreement.

               (b) Counterparts. This Amendment may be executed in any number of
counterparts, each of which shall be deemed an original, but all such
counterparts together shall constitute but one and the same instrument.

        IN WITNESS WHEREOF, we have set our hands hereto as of the date first
above written.

RADIANCE MEDICAL SYSTEMS, INC.


        /s/ Michael R. Henson
------------------------------------------
Michael R. Henson, Chief Executive Officer
   and Chairman of the Board



EXECUTIVE


        /s/ Stephen R. Kroll
------------------------------------------
Stephen R. Kroll



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