PATENT SECURITY AGREEMENT

EXHIBIT 10.4

PATENT SECURITY AGREEMENT

THIS PATENT SECURITY AGREEMENT (the “Agreement”) made as of this 20th day of March, 2006, by CARDIOVASCULAR BIOTHERAPEUTICS, INC., a Delaware corporation (“Grantor”) in favor of Promethean Asset Management L.L.C., on its own behalf and in its capacity as collateral agent (together with its successors and assigns in such capacity, the “Grantee”) for the benefit of the entities identified on the Schedule of Buyers attached to the Purchase Agreement defined below (together with their successors and assigns, the “Lenders”):

WITNESSETH

WHEREAS, on March 20, 2006, Lenders made loans and certain other financial accommodations (collectively, the “Loans”) to Grantor, as evidenced by those certain Senior Secured Notes, dated as of the date hereof, made by Grantor payable to Lenders in the original aggregate principal amount of $20,000,000 (such notes, together with any promissory notes or other securities issued in exchange or substitution therefor or replacement thereof, and as any of the same may be amended, restated, modified or supplemented and in effect from time to time, being herein referred to as the “Notes”).

WHEREAS, the Notes are being acquired by Lenders pursuant to a Securities Purchase Agreement with Borrower dated as of March 20, 2006 (as same may be amended, restated, modified or supplemented and in effect from time to time, the “Purchase Agreement”)

WHEREAS, pursuant to a Security Agreement dated as of March 20, 2006 (as same may be amended, restated, modified or supplemented and in effect from time to time, the “Security Agreement”) among Grantor, the other “Debtors” from time to time party thereto and Grantee, Grantor has granted to Grantee, for the benefit of Lenders, a security interest in substantially all of the assets of Grantor including all right, title and interest of Grantor in, to and under all now owned and hereafter acquired Patents (as defined in the Security Agreement), and all products and proceeds thereof;

NOW, THEREFORE, in consideration of the premises set forth herein and for other good and valuable consideration, receipt and sufficiency of which are hereby acknowledged, Grantor agrees as follows:

1. Incorporation of the Notes, Purchase Agreement and Security Agreement. The Notes, the Purchase Agreement and Security Agreement and the terms and provisions thereof are hereby incorporated herein in their entirety by this reference thereto. All terms capitalized but not otherwise defined herein shall have the same meanings herein as in the Security Agreement.

2. Grant and Reaffirmation of Grant of Security Interests. To secure the payment and performance of the Liabilities, Grantor hereby grants to Grantee, for its benefit and the benefit of Lenders, and hereby reaffirms its prior grant pursuant to the Security Agreement of, a continuing security interest in Grantor’s entire right, title and interest in and to the following (all of the following items or types of property being herein collectively referred to as the “Patent Collateral”), whether now owned or existing and hereafter created, acquired or arising:

(i) each Patent and application for Patent listed on Schedule 1 annexed hereto, together with any reissues, continuations or extensions thereof; and

(ii) all products and proceeds of the foregoing, including, without limitation, any claim by Grantor against third parties for past, present or future infringement of any Patent.

[Signature Pages Follow]

IN WITNESS WHEREOF, Grantor has duly executed this Agreement as of the date first written above.

Agreed and Accepted

As of the Date First Written Above

SCHEDULE 1

U.S. Patents

Page 1 of 7

Foreign Patents

Page 2 of 7

Page 3 of 7

U.S. Patent Applications

Foreign Patent Applications

Page 4 of 7

Page 5 of 7

Patent Licenses

Page 6 of 7

2443398

031506

2444654

031506

2460753

032006

Page 7 of 7