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) See Remarks (Last) (First) (Middle) ARCA BIOPHARMA, INC., 11080 CIRCLEPOINT ROAD, SUITE 140 3. Date of Earliest Transaction (Month/Day/Year) 04/05/2016 (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 04/05/2016   S   724 (1) D $ 3.52 (3) 44,610 (2) D   Common Stock               19,986 I By Investocor Trust as sole Trustee Common Stock               25,459 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

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		See Remarks

Signatures

/s/ Brian L. Selby, Attorney-in-Fact		04/06/2016
**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 of common stock sold pursuant to a Rule 10b5-1 Plan adopted by the Reporting Person for satisfaction of their tax withholding obligation with respect to the vesting of previously reported Restricted Stock Units ("RSUs") granted to the Reporting Person under the Issuer's 2013 Equity Incentive Plan (the "Plan").
(2)	Includes (i) remaining 5,952 previously reported shares issued as RSUs under the Plan that vests on 9/17/16, (ii) remaining 4,050 previously reported shares issued as RSUs under the Plan that vest in two equal annual installments beginning on 2/27/17, and (iii) 4,581 previously reported shares issued as RSUs under the Plan that vest in two equal annual installments beginning 4/2/17, provided that the Reporting Person's continuous service to the Issuer has not been terminated as defined under the Plan; and 30,027 previously reported shares of common stock held directly.
(3)	The price represents the weighted average sale price for multiple transactions reported on this line. The prices of the transactions ranged from $3.52 to $3.524. Upon request of the SEC staff, ARCA biopharma, Inc. (the "Company") or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold at each separate price.
Remarks: President and Chief Executive Officer

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