P2RY12 and COVID-19: In the ACTIV-4a clinical trial, 562 non-critically ill patients hospitalized for COVID-19 were to a therapeutic dose of heparin plus a P2Y12 inhibitor with ticagrelor as a preferred P2Y12 inhibitor or a therapeutic dose of heparin only (usual care) for 14 days or until hospital discharge, whichever was sooner.