Clinical Research Directory

Inclusion Criteria: 1. Age \>18 years. 2. Severe aortic stenosis confirmed by echocardiography, defined as peak aortic jet velocity (Vmax) ≥4.0 m/s, mean transvalvular gradient ≥40 mmHg, or aortic valve area (AVA) ≤1.0 cm² \[or indexed aortic valve area (AVAi) ≤0.6 cm²/m²\]. 3. New York Heart Association (NYHA) functional class II or higher. 4. Eligible for both transfemoral transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR). 5. Undergoing preoperative coronary computed tomography angiography (CCTA). 6. Willing to participate in the study and able to provide written informed consent. Exclusion Criteria: 1. Allergy to prosthetic valve materials or iodinated contrast agents. 2. Contraindication or allergic reaction to anticoagulants or antiplatelet agents, or inability to tolerate required anticoagulant or antiplatelet therapy. 3. Active infective endocarditis or any other active infection. 4. Severe vascular disease precluding safe implantation of a prosthetic valve. 5. Ascending aortic diameter ≥50 mm. 6. Prior prosthetic valve implantation in any cardiac position or prior coronary artery bypass grafting (CABG). 7. Preoperative imaging confirming aortic root anatomy unsuitable for transcatheter aortic valve implantation. 8. Intracardiac mass, left ventricular or left atrial thrombus, or vegetation confirmed by preoperative echocardiography. 9. Acute myocardial infarction within 30 days before surgery. 10. Clinically diagnosed stroke or transient ischemic attack within 3 months before surgery. 11. Bleeding or coagulation disorders within 3 months before surgery that required hospitalization or blood transfusion or were otherwise clinically significant and would preclude the antiplatelet therapy required in this study.