WATCHMAN FLX™ CT Study

Inclusion Criteria: * Subject is of legal age to participate in the study per the laws of their respective geography. * Subject has documented non-valvular atrial fibrillation (i.e., atrial fibrillation in the absence of moderate or greater mitral stenosis or a mechanical heart valve). * Subject is clinically indicated for a WATCHMAN FLX device. * Subject is deemed suitable for the protocol-defined pharmacologic regimen. * Subject or legal representative is able to understand and willing to provide written informed consent to participate in the study. * Subject is able and willing to return for required follow-up visits and examinations. Exclusion Criteria: * Subject is currently enrolled in another investigational study, except if the subject is participating in a mandatory governmental registry, or a purely observational registry with no associated treatment. * Subject has eGFR \<30 mL/min (chronic kidney disease stage IV or stage V). * Subject is contraindicated for TEE. * Subject requires long-term anticoagulation therapy for reasons other than AF-related stroke risk reduction (e.g., due to an underlying hypercoagulable state). * Subject had or is planning to have any cardiac or non-cardiac intervention or surgical procedure within 30 days prior to or 60 days after implant (including, but not limited to, cardioversion, percutaneous coronary intervention, cardiac ablation, cataract surgery, etc.). * Subject had a prior stroke (of any cause, whether ischemic or hemorrhagic) or transient ischemic attack (TIA) within the 30 days prior to enrollment. * Subject had a prior major bleeding event per ISTH definitions within the 30 days prior to enrollment. Lack of resolution of related clinical sequelae or planned and pending interventions to resolve bleeding/bleeding source are a further exclusion regardless of timing of the bleeding event. * Subject has an active bleed. * Subject has a reversible cause for AF or has transient AF. * Subject has no LAA or the LAA is surgically ligated. * Subject has had a myocardial infarction (MI) documented in the clinical record as either a non-ST elevation MI (NSTEMI) or as an ST-elevation MI (STEMI), with or without intervention, within 30 days prior to enrollment. * Subject has a history of atrial septal repair or has an atrial septal defect/patent foramen ovale (ASD/PFO) device. * Subject has a known contraindication to percutaneous catheterization procedure. * Subject has a cardiac tumor. * Subject has signs/symptoms of acute or chronic pericarditis. * Subject has an active infection. * There is evidence of tamponade physiology. * Subject has New York Heart Association Class IV congestive heart failure at the time of enrollment. * Subject is of childbearing potential and is, or plans to become, pregnant during the time of the study (method of assessment per study physician's discretion). * Subject has a documented life expectancy of less than 6 months.