Research Studies

1. The subject is of legal age to participate in the study per the laws of their respective geography. 2. The subject has documented paroxysmal, persistent, permanent or longterm/ longstanding persistent non-valvular atrial fibrillation (i.e., the subject has not been diagnosed with rheumatic mitral valvular heart disease). 3. The subject has a calculated CHA2DS2-VASc score of 2 or greater. 4. The subject is deemed by two study physicians to be unsuitable for oral anticoagulation. 5. The subject is deemed by a study physician to be suitable for the defined protocol pharmacologic regimen of aspirin and clopidogrel* therapy following WATCHMAN Closure Device implant. 6. The subject or legal representative is able to understand and willing to provide written informed consent to participate in the trial. 7. The subject is able and willing to return for required follow-up visits and examinations.