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<!-- Creation Date :2023-10-17T18:23:58.7814+00:00 -->
<!-- Copyright (c) 2023 Donnelly Financial Solutions, Inc. All Rights Reserved. -->
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  <xsd:element id="abio_LesseeOperatingSubleaseTermOfContract" name="LesseeOperatingSubleaseTermOfContract" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="abio_AccruedCompensationAndEmployeeBenefitsMember" name="AccruedCompensationAndEmployeeBenefitsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="abio_NewCapitalOnDemandSalesAgreementMember" name="NewCapitalOnDemandSalesAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="abio_DescriptionOfBusinessPolicyTextBlock" name="DescriptionOfBusinessPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="abio_CommonStockAuthorizedOfferingAmountUnderAgreementToSell" name="CommonStockAuthorizedOfferingAmountUnderAgreementToSell" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="abio_AreaOfRealEstatePropertySubleaseAdditionalOfficeFacilities" name="AreaOfRealEstatePropertySubleaseAdditionalOfficeFacilities" type="dtr-types:areaItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
</xsd:schema>
