Summary

An 86-year-old man had long-standing persistent atrial fibrillation, but had not received any anticoagulants. Transthoracic echocardiography revealed a large thrombus formation in the left atrium. We hesitated to use the conventional anticoagulant, warfarin, because he was very old and had dementia. We decided to resolve the thrombus at our outpatient clinic. He was started on the novel oral anticoagulant, apixaban, 2.5 mg twice daily, which is a direct factor Xa (FXa) inhibitor. After 11 weeks on that therapy, the thrombus formation had almost resolved. During oral anticoagulant therapy, no serious bleeding complications, systemic embolisms or strokes were noted. To the best of our knowledge, we are the first to report that apixaban (5 mg/day) can possibly resolve a thrombus formation in the left atrium.