Transcatheter Self-expandable Valve Implantation for the Treatment of Severe Native Aortic Regurgitation

Inclusion Criteria: 1. Procedural indications: symptomatic severe aortic regurgitation; no symptom plus left ventricular ejection fraction ≤ 55% or left ventricular end-diastolic dimension (LVEDD) \> 65mm or left ventricular end-systolic dimension (LVESD) \> 50mm; 2. Severe aortic valve regurgitation, and mean pressure gradient \< 20mmHg; Annular perimeter ≤ 85 mm; 3. The ratio of the perimeter of the left ventricular outflow tract 4mm to the perimeter of the valve annulus is 0.95-1.05; 4. STS score ≥8 or moderate to severe frailty or refused surgical valve replacement or presence of any of the following factors judged to be difficult to perform the surgical valve replacement: 1. Severe aorta calcification or active ascending aorta atherosclerotic plaque 2. History of mediastinum radiotherapy 3. Past mediastinitis 4. Presence of unobstructed coronary bypass implants 5. Previous more than two cardiothoracic surgeries 6. Liver cirrhosis 7. Other surgical risk factors Exclusion Criteria: 1. Age \< 60 years old; 2. Ascending aorta diameter \>45mm; 3. Coronary multi-vessel disease (SYNTAX score \>32); 4. Life expectancy \<1 year; 5. Left ventricular ejection fraction \<30%; 6. Acute myocardial infarction within 30 days; 7. Allergies or contraindications to related drugs (aspirin, clopidogrel, warfarin, or contrast agents); 8. Other situations judged by the researcher as unsuitable for participating in the study.