Aspirin Discontinuation After Left Atrial Appendage Occlusion in Atrial Fibrillation

The ASPIRIN LAAO trial is a prospective, multi-center, randomized, double blinded, placebo-controlled study aiming at investigating the safety of terminating the use of aspirin after left atrial appendage occlusion (LAAO).

Patients diagnosed with atrial fibrillation and have undergone LAAO will be enrolled in this study. Randomization will be performed at 6 months post-implant. The randomization program electronically assigns the patient 1:1 to either the Aspirin group or the control group. Study patients assigned to Aspirin group will receive enteric coated aspirin (100 mg/day). The control group receives placebo. After the randomization, subjects of both groups will have follow-up visits at 6 and 12 months and then every 12 months until 24 months after the last patient recruitment. For each group, 560 patients will be included, with an estimated total number of 1120 participants in this clinical study. Patients will be followed up until 24 months after the last enrollment.

The primary endpoint is a composite consisting of stroke, systemic embolism, cardiovascular or unexplainable death, acute coronary syndrome, coronary artery disease or periphery vascular disease requiring revascularization and major bleeding. The secondary endpoints are all-cause death, device related thrombus, minor bleeding and rehospitalization due to heart failure.

The ASPIRIN LAAO trial is a prospective, multi-center, randomized, double blinded, placebo-controlled study aiming at investigating the safety of terminating the use of aspirin since the sixth month after LAAO.

Patients diagnosed with paroxysmal or persistent atrial fibrillation with an age between 18 and 90 years and have undergone LAAO will be enrolled in this study. Randomization will be performed at 6 months post-implant. The randomization program electronically assigns the patient 1:1 to either the Aspirin group or the control group. Study patients assigned to Aspirin group will receive enteric coated aspirin (100 mg/day). The control group receives placebo. After the randomization, subjects of both groups will have follow-up visits at 6 and 12 months and then every 12 months until 24 months after the last patient recruitment. For each group, 560 patients will be included, with an estimated total number of 1120 participants in this clinical study. Patients will be followed up until 24 months after the last enrollment.

The primary endpoint is a composite consisting of stroke, systemic embolism, cardiovascular or unexplainable death, acute coronary syndrome, coronary artery disease or periphery vascular disease requiring revascularization and major bleeding. The secondary endpoints are all-cause death, device related thrombus, minor bleeding and rehospitalization due to heart failure.

Eligibility Criteria:
Inclusion Criteria:

* Age between 18 and 90 years
* Paroxysmal, persistent, long-standing persistent or permanent nonvalvular AF
* Have already had a Watchman LAAO device implanted 6 months ago

Exclusion Criteria:

Clinical Exclusion Criteria

* Long-term aspirin therapy required
* Including coronary artery disease, symptomatic carotid disease, prior myocardial infarction, strokes or systemic embolism, etc
* Contraindicated for aspirin therapy
* Including active peptic ulcer, thrombocytopenia or anemia, etc.
* Uncontrolled malignant tumor
* Abnormal liver, renal or coagulation function
* Pregnant or pregnancy is planned during the course of the investigation
* Terminal illness with life expectancy \<1 year
* Enrolled in another IDE or IND investigation of a cardiovascular device or an investigational drug

TEE Exclusion Criteria\*

* Peri-device leak \>5mm
* Device-related thrombus
* Other intracardiac thrombus