WATCHMAN FLX Pro European Registry

Inclusion Criteria: 1. Subject is attempted to be treated with the WATCHMAN FLX™ Pro LAAC device. 2. Subject has non-valvular atrial fibrillation (i.e., atrial fibrillation in the absence of moderate or greater mitral stenosis or a mechanical heart valve) and is clinically indicated for a WATCHMAN FLX™ Pro LAAC device, per the Instructions for Use (IFU). 3. Subject or legal representative who are willing and capable of providing informed consent. 4. Subject is able and willing to return for required follow-up visits and examinations. 5. Subject whose age is 18 years or above, or who is of legal age to give informed consent specific to state and national law. Exclusion Criteria: 1. Subject has a documented life expectancy of less than 12 months. 2. Subject who is currently enrolled in another investigational study or registry except when the subject is participating in a mandatory governmental registry, or a purely observational registry with no associated treatments. 3. Intracardiac thrombus is present. 4. An atrial septal defect repair or closure device or a patent foramen ovale repair or closure device is present. 5. The LAA anatomy will not accommodate a Closure Device. 6. Subject has a known hypersensitivity or contraindications according to IFU. 7. Subject is of childbearing potential and is, or plans to become, pregnant during the time of the study.