In the open-label, phase IIIb ENSURE-AF trial, 2,199 patients undergoing electrical cardioversion of atrial fibrillation (AF) were randomly assigned to receive the oral direct factor Xa inhibitor edoxaban (60 mg daily), or enoxaparin and warfarin. The primary efficacy and safety end points occurred in only 1% of patients in each group. On the basis of the low rates of major bleeding and thromboembolism, the investigators conclude that “edoxaban is an effective and safe alternative to the best possible conventional treatment with enoxaparin and vitamin K antagonist strategy and might allow prompt cardioversion to be performed”.