BROOMFIELD, Colo.--(BUSINESS WIRE)--ARCA biopharma, Inc. (Nasdaq: ABIO), a biopharmaceutical company developing genetically-targeted therapies for atrial fibrillation, heart failure and other cardiovascular diseases, today provided an update on a proposed, genetically-targeted clinical trial in atrial fibrillation (???AF???) of the Company???s lead developmental drug, Gencaro (bucindolol hydrochlo