Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
BRISTOW MICHAEL R
  2. Issuer Name and Ticker or Trading Symbol
ARCA biopharma, Inc. [ABIO]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
President and CEO
(Last)
(First)
(Middle)
ARCA BIOPHARMA, INC., 11080 CIRCLEPOINT ROAD, SUITE 140
3. Date of Earliest Transaction (Month/Day/Year)
02/27/2014
(Street)

WESTMINSTER, CO 80020
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 02/27/2014   A   56,700 (1) A $ 1.95 306,478 (2) D  
Common Stock               139,082 I By Investocor Trust as sole Trustee
Common Stock               178,215 I By NFS Custodian for Michael Bristow's IRA

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Option (right to buy) $ 1.95 02/27/2014   A   51,500     (3) 02/27/2024 Common Stock 51,500 $ 0 51,500 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BRISTOW MICHAEL R
ARCA BIOPHARMA, INC.
11080 CIRCLEPOINT ROAD, SUITE 140
WESTMINSTER, CO 80020
  X     President and CEO  

Signatures

 /s/ Patrick M. Wheeler, Attorney-in-Fact   03/03/2014
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Represents shares issued as restricted stock units (an "RSU") under the Issuer's 2013 Equity Incentive Plan (the "Plan"). The RSUs vest in four equal annual installments from the date of grant, provided that the Reporting Person's continuous service to the Issuer has not been terminated as defined in or as determined under the Plan prior to such time.
(2) Includes 125,000 previously reported shares issued as restricted stock units under the Plan.
(3) (3) Grant to the Reporting Person of a stock option under the Plan, vesting in 48 equal monthly installments from the date of grant, provided that the Reporting Person's continuous service to the Issuer has not been terminated as defined in or as determined under the Plan prior to such time. In the event of a change in control of the Issuer, 50% of the unvested options shall become fully and immediately vested upon the closing date of such change in control, provided, however, that on the earlier of (i) the one-year anniversary of the closing date or (ii) involuntary termination, any options that remain unvested on such earlier date shall become fully and immediately vested.

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