FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF 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 *   Grais Linda S 2. Date of Event Requiring Statement (Month/Day/Year) 01/27/2009 3. Issuer Name and Ticker or Trading Symbol ARCA biopharma, Inc. [ABIO] (Last) (First) (Middle) C/O INTERWEST PARTNERS IX, LP, 2710 SAND HILL ROAD, SECOND FLOOR 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) MENLO PARK, CA 94025 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 Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 702,698 I See Footnote (1)

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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Warrant to Purchase Common Stock	  (2)	10/10/2013	Common Stock	30,015	$ 9.7406	I	See Footnote (3)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Grais Linda S C/O INTERWEST PARTNERS IX, LP 2710 SAND HILL ROAD, SECOND FLOOR MENLO PARK, CA 94025	  X	Â	Â	Â

Signatures

Patrick Wheeler, attorney in fact		02/05/2009
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(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)	These shares are owned directly by InterWest Partners IX, LP. Ms. Grais, one of ARCA's directors, is a venture member of InterWest Management Partners IX, LLC, the general partner of InterWest Partners IX, LP. Ms Grais has shared voting and dispositive powers over the shares held by InterWest Partners IX, LP. She disclaims beneficial ownership of these shares, except to the extent of her pro rata partnership interest therein.
(2)	This warrant is immediately exercisable.
(3)	This warrant is owned directly by InterWest Partners IX, LP. Ms. Grais, one of ARCA's directors, is a venture member of InterWest Management Partners IX, LLC, the general partner of InterWest Partners IX, LP. Ms Grais has shared voting and dispositive powers over the shares held by InterWest Partners IX, LP. She disclaims beneficial ownership of these shares, except to the extent of her pro rata partnership interest therein.

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