The standard antithrombotic therapy for treatment of patients with acute coronary syndrome (ACS) is dual antiplatelet therapy with aspirin and clopidogrel (Plavix) or another thienopyridine, plus a parenteral anticoagulant while the patient is hospitalized, followed by antiplatelet therapy alone after discharge. The addition of the oral anticoagulant warfarin (Coumadin, and others) to dual antiplatelet therapy is generally not recommended for this indication because of fluctuations in its anticoagulant effect and the risk of bleeding. A recently published trial found that addition of a low dose of the oral anticoagulant rivaroxaban (Xarelto) to antiplatelet therapy after discharge reduced the risk of major cardiovascular events without increasing the incidence of fatal bleeding.