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 <1 year (e.g., terminal malignancy).
• Participation in another investigational drug or device clinical study (patients who have completed the primary endpoint of the study and are currently in long-term follow-up are not excluded).
• Pregnancy or planned pregnancy, or use of estrogen or estrogen-like drugs (for women with suspected pregnancy, serum or urine human chorionic gonadotropin test must be negative before enrollment).
• Any other condition deemed by the investigator to be inappropriate for study participation.