Clinical Research Directory

Inclusion Criteria: 1. Age ≥ 65 years ; 2. Patients with symptomatic severe aortic valve stenosis (evaluated by echocardiography: transaortic valve pressure gradient ≥40mmHg (1mmHg=0.133kPa), or transaortic valve blood flow rate ≥4m/s, or aortic Valve area\<1.0cm², or AVA \<0.5cm² /m²); 3. Cardiac function NYHA ≥ II; 4. Life expectancy\> 12 months; 5. Patients who are anatomically suitable for transcatheter aortic valve implantation; 6. Patients who have been evaluated by two or more cardiovascular surgeons as unsuitable for conventional surgery; or patients who have refused conventional surgery after adequate communication from the surgeon and who are at high risk for conventional surgery; 7. Patients who can understand the purpose of the trial and volunteer to participate in, sign the informed consent form and are willing to accept relevant examinations and clinical follow-ups. Exclusion Criteria: 1. Acute myocardial infarction occurred within 1 month before this treatment; 2. Congenital unicuspid aortic valve; 3. Any therapeutic cardiac operation that is performed within 30 days of the index procedure (Previous PCI or implantation of a permanent pacemaker are not considered exclusion criteria); 4. Patients with other prosthetic heart valves, prosthetic rings already implanted in the heart, or severe mitral valve closure insufficiency (\>3+); 5. Patients with hematologic disorders or abnormalities that make surgical treatment inappropriate; 6. Untreated severe coronary artery stenosis that requires revascularization; 7. Patients with hemodynamic or respiratory instability, requiring continuous mechanical heart assistance or mechanical ventilation; 8. Patients who need emergency surgery for any reason; 9. Patients with hypertrophic cardiomyopathy with obstruction; 10. Severe left ventricular dysfunction, left ventricular ejection fraction (LVEF) \<20%; 11. Echocardiographic evidence of intracardiac mass, thrombus or vegetation; 12. Patients with left ventricular outflow tract obstruction; 13. A history of acute peptic ulcer or upper gastrointestinal bleeding within 3 months; 14. Patients who are allergy or resistance to cobalt-chromium alloy, contrast agents and related components; 15. Patients who are unable to receive anticoagulation or antiplatelet therapy; 16. Cerebrovascular accident occurred within 3 months, not including transient ischemic attack; 17. Severe aortic diseases, including abdominal aortic or thoracic aortic aneurysm, etc; 18. Active infective endocarditis or other active infections; 19. Patients who have participated in clinical trials of other drugs or medical devices before enrollment and have not yet reached the primary outcome of research; 20. The investigator judged that patient with poor compliance and could not complete the study as required.