Evaluation of the WATCHMAN Left Atrial Appendage (LAA) Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy

This was a prospective, randomized, multicenter study to provide additional information on the safety and efficacy of the WATCHMAN LAA Closure Technology. The purpose of the PREVAIL study was to confirm the efficacy endpoint as demonstrated in the PROTECT AF pivotal study and to further demonstrate that the WATCHMAN LAA Closure Technology is safe and effective in subjects with non-valvular atrial fibrillation who require anticoagulation therapy for potential thrombus formation.