<SEC-DOCUMENT>0001564590-21-017811-index.html : 20210406
<SEC-HEADER>0001564590-21-017811.hdr.sgml : 20210406
<ACCEPTANCE-DATETIME>20210406161304
ACCESSION NUMBER:		0001564590-21-017811
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		4
CONFORMED PERIOD OF REPORT:	20210402
ITEM INFORMATION:		Entry into a Material Definitive Agreement
ITEM INFORMATION:		Shareholder Nominations Pursuant to Exchange Act Rule 14a-11
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20210406
DATE AS OF CHANGE:		20210406

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ARCA biopharma, Inc.
		CENTRAL INDEX KEY:			0000907654
		STANDARD INDUSTRIAL CLASSIFICATION:	IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES [2835]
		IRS NUMBER:				363855489
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		8-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22873
		FILM NUMBER:		21809314

	BUSINESS ADDRESS:	
		STREET 1:		10170 CHURCH RANCH WAY
		STREET 2:		SUITE 100
		CITY:			WESTMINSTER
		STATE:			CO
		ZIP:			80021
		BUSINESS PHONE:		7209402200

	MAIL ADDRESS:	
		STREET 1:		10170 CHURCH RANCH WAY
		STREET 2:		SUITE 100
		CITY:			WESTMINSTER
		STATE:			CO
		ZIP:			80021

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NUVELO INC
		DATE OF NAME CHANGE:	20030203

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	HYSEQ INC
		DATE OF NAME CHANGE:	19970610
</SEC-HEADER>
<DOCUMENT>
<TYPE>8-K
<SEQUENCE>1
<FILENAME>abio-8k_20210402.htm
<DESCRIPTION>8-K
<TEXT>
Document 1 - file: abio-8k_20210402.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>2
<FILENAME>abio-ex51_7.htm
<DESCRIPTION>EX-5.1
<TEXT>
Document 2 - file: abio-ex51_7.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-10.1
<SEQUENCE>3
<FILENAME>abio-ex101_6.htm
<DESCRIPTION>EX-10.1
<TEXT>
Document 3 - file: abio-ex101_6.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>gaavqm1vj4rf000001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: gaavqm1vj4rf000001.jpg

</DOCUMENT>
</SEC-DOCUMENT>