Embolic stroke during apixaban therapy for left atrial appendage thrombus

Left atrial appendage (LAA) thrombus is associated with atrial fibrillation (AF) and is a powerful predictor of cardiogenic thromboembolism. Warfarin is an established anticoagulant therapy for patients with LAA thrombus to prevent thromboembolic complications. Apixaban is superior to warfarin in the prevention of thromboembolic complications in patients with AF, and there are case reports showing apixaban-associated resolution of LAA thrombus; however, the efficacy and safety of apixaban for the treatment of LAA thrombus remains unproven. Here we report a patient who experienced embolic stroke while taking apixaban for the treatment of LAA thrombus. Thrombolysis therapy was initiated at the onset of stroke and the patient recovered remarkably. Apixaban is known to make thrombi mobile and/ or fragile by shifting the coagulation/fibrinolysis balance to a relative predominance of fibrinolytic activity; therefore, it is necessary to monitor for thromboembolic complications after the initiation of apixaban for the treatment of pre-existing LAA thrombus.