Catheter Ablation Plus LAAO Versus Anticoagulation in Frail Elderly Patients With Atrial Fibrillation

Inclusion Criteria: (1) Age ≥ 75 years. (2) Confirmed diagnosis of non-valvular atrial fibrillation (paroxysmal or persistent). (3) CHA2DS2-VASc score ≥ 3 (high risk of stroke) . (4) Procedure-related criteria: Sequential Group: Participants who have received catheter ablation for non-valvular AF within 90 to 180 days prior to randomization. One-stop Group: Participants who are scheduled to undergo clinically indicated catheter ablation within 10 days after randomization. (5) Judged by the investigator to be able to tolerate the defined antithrombotic drug regimen. (6) Suitable to undergo Transesophageal Echocardiography (TEE) or Pulmonary Vein Computed Tomography (CT). (7) Able and willing to sign the written informed consent form. (8) Willing to return for all scheduled follow-up visits and examinations. Exclusion Criteria: (1) Presence of thrombus in the left atrium or left atrial appendage identified on preoperative imaging (echocardiogram, pulmonary vein CT, etc). (2) Major bleeding event (per ISTH definition) within 14 days prior to randomization. Participants must be excluded if clinical sequelae persist or if interventions for the bleeding source are planned/pending, regardless of the time elapsed since the event. (3) Requirement for long-term oral anticoagulation (OAC) for reasons other than stroke risk reduction in AF (e.g., underlying hypercoagulable state) that would prevent OAC discontinuation post-device implantation. (4) Any cardiac or major non-cardiac intervention/surgery (excluding AF ablation and cardioversion) performed within 30 days prior to, or scheduled within 60 days after randomization. This includes but is not limited to Percutaneous Coronary Intervention (PCI) or other cardiac ablations. (5) Life expectancy \< 2 years, malignancy, infectious endocarditis, uncontrolled infection, or physiological evidence of cardiac tamponade. (6) Clinical Frailty Scale (CFS) score of 1-3 (not frail) or 7-9 (severely frail/terminally ill). (7) Deemed unsuitable for long-term anticoagulation and/or antiplatelet therapy by the investigator due to bleeding risk, allergies, or other reasons. (8) Current participation in another clinical trial that interferes with this study, excluding mandatory government or purely observational registries. (9) Stroke or transient ischemic attack (TIA) within 60 days prior to randomization. (10) Documented myocardial infarction (NSTEMI or STEMI) within 90 days prior to randomization, regardless of intervention. (11) History of atrial septal defect (ASD) repair or presence of an ASD/Patent Foramen Ovale (PFO) occluder. (12) Presence of a mechanical prosthetic valve in any position. (13) Participants of childbearing potential who are pregnant or planning pregnancy during the study period. (14) Medical or anatomical contraindications to percutaneous catheter-based interventions. (15) Documented NYHA Class IV heart failure. (16) History of surgical left atrial appendage (LAA) closure. Transthoracic Echocardiography (TTE) Specific Exclusions: (1) Low LVEF: Left ventricular ejection fraction (LVEF) \< 30%. (2) Presence of pericardial effusion with a circumferential echo-free space \> 5mm. (3) Presence of high-risk PFO associated with an atrial septal aneurysm (ASA) with an excursion or length \> 15mm. (4) Presence of high-risk PFO with a large shunt (defined as appearance of microbubbles within 3 cardiac cycles and/or a substantial count of microbubbles). (5) Presence of moderate or severe mitral stenosis (mitral valve area \< 1.5 cm2).