    <SEC-DOCUMENT>0001564590-19-010923-index.html : 20190405
    <SEC-HEADER>0001564590-19-010923.hdr.sgml : 20190405
    <ACCEPTANCE-DATETIME>20190405161530
    ACCESSION NUMBER:		0001564590-19-010923
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		30
    CONFORMED PERIOD OF REPORT:	20190405
    ITEM INFORMATION:		Other Events
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20190405
    DATE AS OF CHANGE:		20190405

    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:		19735296

    	BUSINESS ADDRESS:
    		STREET 1:		11080 CIRCLEPOINT ROAD
    		STREET 2:		SUITE 140
    		CITY:			WESTMINSTER
    		STATE:			CO
    		ZIP:			80020
    		BUSINESS PHONE:		720-940-2200

    	MAIL ADDRESS:
    		STREET 1:		11080 CIRCLEPOINT ROAD
    		STREET 2:		SUITE 140
    		CITY:			WESTMINSTER
    		STATE:			CO
    		ZIP:			80020

    	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_20190405.htm
    <DESCRIPTION>8-K
    <TEXT>
    Document 1 - file: abio-8k_20190405.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>2
    <FILENAME>abio-ex991_6.htm
    <DESCRIPTION>EX-99.1
    <TEXT>
    Document 2 - file: abio-ex991_6.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>gry5gzesyvfz000001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 3 - file: gry5gzesyvfz000001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>gry5gzesyvfz000002.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 4 - file: gry5gzesyvfz000002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>gry5gzesyvfz000018.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 5 - file: gry5gzesyvfz000018.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>gry5gzesyvfz000025.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: gry5gzesyvfz000025.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>gry5gzesyvfz000010.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: gry5gzesyvfz000010.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>gry5gzesyvfz000026.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: gry5gzesyvfz000026.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>gry5gzesyvfz000014.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: gry5gzesyvfz000014.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>gry5gzesyvfz000003.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: gry5gzesyvfz000003.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>gry5gzesyvfz000004.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: gry5gzesyvfz000004.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>gry5gzesyvfz000011.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: gry5gzesyvfz000011.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>gry5gzesyvfz000023.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: gry5gzesyvfz000023.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>gry5gzesyvfz000013.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: gry5gzesyvfz000013.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>gry5gzesyvfz000015.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: gry5gzesyvfz000015.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>gry5gzesyvfz000007.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: gry5gzesyvfz000007.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>gry5gzesyvfz000008.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 17 - file: gry5gzesyvfz000008.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>gry5gzesyvfz000005.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 18 - file: gry5gzesyvfz000005.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>gry5gzesyvfz000009.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 19 - file: gry5gzesyvfz000009.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>gry5gzesyvfz000027.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 20 - file: gry5gzesyvfz000027.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>gry5gzesyvfz000017.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 21 - file: gry5gzesyvfz000017.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>22
    <FILENAME>gry5gzesyvfz000022.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 22 - file: gry5gzesyvfz000022.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>23
    <FILENAME>gry5gzesyvfz000028.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 23 - file: gry5gzesyvfz000028.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>24
    <FILENAME>gry5gzesyvfz000006.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 24 - file: gry5gzesyvfz000006.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>25
    <FILENAME>gry5gzesyvfz000024.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 25 - file: gry5gzesyvfz000024.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>26
    <FILENAME>gry5gzesyvfz000016.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 26 - file: gry5gzesyvfz000016.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>27
    <FILENAME>gry5gzesyvfz000021.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 27 - file: gry5gzesyvfz000021.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>28
    <FILENAME>gry5gzesyvfz000020.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 28 - file: gry5gzesyvfz000020.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>29
    <FILENAME>gry5gzesyvfz000019.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 29 - file: gry5gzesyvfz000019.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>30
    <FILENAME>gry5gzesyvfz000012.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 30 - file: gry5gzesyvfz000012.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>