-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0000908662-07-000340.txt : 20070928
<SEC-HEADER>0000908662-07-000340.hdr.sgml : 20070928
<ACCEPTANCE-DATETIME>20070928125642
ACCESSION NUMBER:		0000908662-07-000340
CONFORMED SUBMISSION TYPE:	3/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070806
FILED AS OF DATE:		20070928
DATE AS OF CHANGE:		20070928

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HEALTHCARE ACQUISITION CORP
		CENTRAL INDEX KEY:			0001326190
		STANDARD INDUSTRIAL CLASSIFICATION:	BLANK CHECKS [6770]
		IRS NUMBER:				202726770
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2116 FINANCIAL CENTER
		STREET 2:		666 WALNUT STREET
		CITY:			DES MOINES
		STATE:			IA
		ZIP:			50309
		BUSINESS PHONE:		515-244-5746

	MAIL ADDRESS:	
		STREET 1:		2116 FINANCIAL CENTER
		STREET 2:		666 WALNUT STREET
		CITY:			DES MOINES
		STATE:			IA
		ZIP:			50309

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CZEREPAK ELIZABETH
		CENTRAL INDEX KEY:			0001263500

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32587
		FILM NUMBER:		071141521

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		301 944 6600

	MAIL ADDRESS:	
		STREET 1:		20425 SENECA MEADOWS PARKWAY
		CITY:			GERMANTOWN
		STATE:			MD
		ZIP:			20876
</SEC-HEADER>
<DOCUMENT>
<TYPE>3/A
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2007-08-06</periodOfReport>

    <dateOfOriginalSubmission>2007-08-08</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001326190</issuerCik>
        <issuerName>HEALTHCARE ACQUISITION CORP</issuerName>
        <issuerTradingSymbol>PIP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001263500</rptOwnerCik>
            <rptOwnerName>CZEREPAK ELIZABETH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BEAR STEARNS HEALTH INNOVENTURES, LP</rptOwnerStreet1>
            <rptOwnerStreet2>237 PARK AVENUE, 7TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1320087</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held by Bear Stearns Health Innoventures Group</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>8% Convertible Notes</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2007-08-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-08-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>254106</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held by Bear Stearns Health Innoventures Group</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.22</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2007-08-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2016-01-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1104</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held by Bear Stearns Health Innoventures Group</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Received in connection with the merger of PharmAthene, Inc. with a wholly-owned subsidiary of Healthcare Acquisition Corp. (the &quot;Merger&quot;) on August 3, 2007, after which Healthcare Acquisition Corp. changed its name to PharmAthene, Inc.  Elizabeth Czerepak was appointed to the Board as of August 6, 2007.  This amendment reflects the final consideration received in the Merger, including adjustments.</footnote>
        <footnote id="F2">Elizabeth Czerepak is a managing partner of Bear Stearns Innoventures Management, LLC (&quot;Management&quot;).  Management is the sole general partner of Bear Stearns Health Innoventures, L.P. (&quot;BSHI&quot;), Bear Stearns Health Innoventures Offshore, L.P. (&quot;Offshore&quot;), BX, L.P. (&quot;BX&quot;), and Bear Stearns Health Innoventures Employee Fund, L.P. (&quot;Employee Fund&quot;), and BSHI Members, LLC (&quot;Members&quot;) co-invests with these funds.  The securities reported are directly owned by Members, BSHI, Offshore, BX, and Employee Fund.  The Reporting Person disclaims beneficial ownership of these securitries except to the extent of her proportionate pecuniary interest therein.</footnote>
        <footnote id="F3">Represents $2,541,079 principal amount of converitble notes received in connection with the Merger in exchange for existing convertible notes of PharmAthene, Inc., the acquired company.</footnote>
        <footnote id="F4">Represents existing stock options of PharmAthene, Inc., the acquired company, that were assumed in the Merger.  Options vest in 25% annual increments beginning January 18, 2007.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Elizabeth Czerepak</signatureName>
        <signatureDate>2007-09-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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