ENSURE-AFA Prospective, Randomized, Open-Label Blinded Endpoint Evaluation (PROBE) Parallel Group Study Comparing Edoxaban (DU-176b) With Enoxaparin/Warfarin Followed by Warfarin Alone in Subjects Undergoing Planned Electrical Cardioversion of Nonvalvular Atrial Fibrillation

The purpose of this study is to compare edoxaban (investigational drug) with warfarin and enoxaparin, to see if it is safe and effective in preventing stroke and other blood clot complications in subjects with atrial fibrillation whose doctors plan to treat them with an electrical cardioversion. It is expected that 284 sites will recruit 2200 subjects from North America, EU, Russia, Ukraine and Israel. Participants will be randomly allocated to receive either treatment with edoxaban, or treatment with warfarin, plus enoxaparin if required. Participants will have an equal chance of receiving either treatment. Participants will be in the study for a maximum of 82 days. Study procedures will include physical examinations, vital signs (pulse and sitting blood pressure), ECG (electrocardiogram), finger prick blood clotting tests, blood samples and urine samples. The study is expected to show that edoxaban will provide comparable incidence rates to warfarin plus enoxaparin, the current standard treatment for both efficacy and bleeding.