Aspirin Monotherapy Versus Sequential Warfarin-Aspirin Therapy After TAVR in Patients With Pure Aortic Regurgitation

This multicenter randomized controlled trial evaluates antithrombotic strategies post-TAVR in severe aortic regurgitation patients without long-term anticoagulation. Patients are randomized 1:1 to aspirin 75-100 mg daily for 12 months versus warfarin (INR 2-3) for 6 months followed by aspirin for 6 months. Primary hypothesis: aspirin is superior for bleeding and non-inferior for death/thrombosis. Primary endpoint is a composite of death, stroke, thrombosis, MI, embolism, and major bleeding at 1 year. Sample size: 1172. Follow-up: 30 days, 6 months, 12 months.

Inclusion Criteria: * Age ≥18 years. * Patients with severe aortic regurgitation (AR) who achieve technical success after TAVR using devices specifically indicated for AR (per VARC-3 criteria). * Trileaflet aortic valve anatomy. * No long-term anticoagulation indication (including but not limited to: atrial fibrillation, mechanical mitral valve prosthesis, deep vein thrombosis, pulmonary embolism, left ventricular thrombus, pulmonary hypertension, or coagulation disorders) as confirmed by the investigator. * Signed written informed consent and willingness to comply with randomization, study procedures, and follow-up. Exclusion Criteria: * Need for oral anticoagulation or dual antiplatelet therapy, or need for oral or intravenous strong CYP3A inhibitors that cannot be paused during the study period. * Active pathological bleeding, subdural hematoma, or history of intracranial hemorrhage. * Ischemic stroke within 30 days before TAVR. * Acute myocardial infarction within 30 days. * Severe hepatic insufficiency (cirrhosis, hepatic decompensation). * Severe renal insufficiency (eGFR \< 30 mL/min/1.73 m²) or need for renal replacement therapy. * Stent implantation (including coronary, carotid, or peripheral arteries) within 12 months before TAVR, or planned stent implantation within 1 year after TAVR. * Coronary artery bypass grafting (CABG) within 12 months before TAVR. * Allergy, intolerance, or known resistance to aspirin, clopidogrel, or warfarin. * Known coagulation disorders or bleeding diathesis (including but not limited to platelet count ≤50,000/mm³ at screening). * Any contraindication to anticoagulation therapy. * Prior aortic valve prosthesis (mechanical or bioprosthetic); mitral valve bioprosthesis replacement within 1 year before TAVR; or prior mitral mechanical valve replacement; or prior tricuspid valve replacement. * Emergency TAVR with cardiogenic shock manifesting as low cardiac output, vasopressor or respiratory dependence, or mechanical hemodynamic support. * Life expectancy \