Exhibit 31.3

CERTIFICATION

I, Michael Bristow certify that:

1. I have reviewed this annual report on Form 10-K/A of ARCA biopharma, Inc.; and

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.

Date: April 18, 2013

/s/ MICHAEL R. BRISTOW

Michael R. Bristow

President and Chief Executive Officer