Antithrombotic Strategy Based on Clinical Events and 4D-CT for Patients After TAVR

Inclusion Criteria: * Patients aged 18-85 years old with severe aortic stenosis; * Successful TAVR via femoral artery approach (VARC 3 device success criteria); * Implantation of self-expanding bioprosthetic valve; * Be willing to give informed consent. Exclusion Criteria: * Patients with anticoagulant indications, such as atrial fibrillation, intracardiac thrombosis, deep vein thrombosis, pulmonary embolism, history of mechanical valve implantation; * Patients needed double antiplatelet therapy, such as acute myocardial infarction within one year, coronary stent implantation within 6 months, peripheral artery stent implantation within 3 months; * Patients who received concomitant TAVR and percutaneous coronary intervention; * Patients with peptic ulcers or active bleeding or history of cerebral hemorrhage * Patients with ischemic stroke or TIA within 6 months; * Patients with left ventricular ejection fraction \< 30% or pulmonary hypertension (\>70mmHg) before discharge; * Patients intolerant or allergic to aspirin or Vitamin-K antagonists (warfarin); * Patients with evaluated glomerular filtration rate \<15ml/min/m2 (Cockcroft formula) or on dialysis; * Patients with poor compliance, unable to complete the study and follow-up as required; * Patients' life expectancy less than 1 year; * Patients who already participated in other clinical trials (within the last 30 days).