Non-antithrombotic Versus. Single Antiplatelet Therapy Following Left Atrial Appendage Closure

Inclusion Criteria:

1. Patient has documented non-valvular atrial fibrillation (i.e, atrial fibrillationwithout severe mitral stenosis or mechanical valves)

2. Patient has CHA2DS2-VA score of 2 or greater

3. Patient meets the guidelines for proper use of the left atrial appendage closuresystem including patient who has an increased risk of bleeding.

4. Individual with nonvalvular atrial fibrillation who underwent successful LAAC (defined as no significant residual circumferential leak [>3 mm] or major morbidityby the time of procedure completion).

5. Patient suitable for pharmacotherapy as defined in this study protocol in both NAPTand SAPT arms

6. LAA anatomy is accommodate Boston Scientific WATCHMAN FLX Pro and LAAC procedure

7. The patient and the investigator and/or subinvestigator agree that the patient willreturn for all required VISITs after LAAC procedure

8. Patient has thoroughly understood the purpose of the study and has provided writteninformed consent to participate in the study

Exclusion Criteria:

1. Patients who are currently enrolled in other clinical trials, except when thepatient is participating in a mandatory governmental registries or purelyobservational registries with no associated treatment.

2. Individuals require long-term anticoagulation therapy for reasons other than atrialfibrillation (AF)-related stroke risk reduction (e.g.,thrombophilic conditions,previous pulmonary embolism, or deep venous thrombosis).

3. Patients requiring oral antiplatelet therapy for reasons other than LAAC (e.g.,history of myocardial infarction, history of endovascular treatment, historyof stroke/transient ischemic attack, significant coronary stenosis proven bymyocardial ischemia, severe carotid stenosis requiring invasivetreatment,hematologic disease such as antiphospholipid syndrome or if theinvestigator and/or subinvestigator judged the need for antiplatelet therapy).

4. Patients who meet one or more of the following criteria

• Patients who are contraindicated for DOAC or VKA

• Patients with a contraindication to aspirin

• Patients diagnosed with an allergy to aspirin

5. Those who have or are scheduled to undergo cardiac or noncardiac intervention orsurgery 45 days or 60 days before or after LAAC (e.g.,cardioversion, PCI, cardiacablation, cataract surgery, other structural heart interventions).

6. Patients with stroke (either ischemic or hemorrhagic) or transient ischemic attackwithin 30 days prior to enrollment

7. Patients with active bleeding

8. Individuals who lack LAA or whose LAA has been surgically ligated

9. Individuals who experienced a myocardial infarction (with or without intervention)recorded as a non-ST elevation myocardial infarction or ST elevation myocardialinfarction in the 30-day period prior to enrollment

10. Patients with previous atrial septal repair or with atrial septal defect/patentforamen ovale device

11. Patients with mechanical valve prostheses at any site

12. Persons with known contraindications to TEE

13. Patients with active infection

14. Individuals with NYHA class related IV congestive heart failure at enrollment

15. Patients who are pregnant, breastfeeding, or wishing to become pregnant

16. Patients with an expected life expectancy of less than 2 years

17. Patients requiring emergency surgery for any reason

18. Patients who, at the discretion of the investigator, have other medical, social, orpsychological conditions that preclude adherence to appropriate consent or thefollow-up tests required by the protocol

19. Other patients whose investigator or subinvestigator judges their participation inthe study to be inappropriate