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

Patients with severe native aortic valve regurgitation (AR) who have symptoms, impaired LVEF (≤55%) or left ventricular enlargement have the indications for surgery. According to data from the Euro Heart Survey, only 21.8% with LVEF 30-50% and 2.7% with LVEF <30% were referred for surgical aortic valve replacement (SAVR) among patients with severe native aortic regurgitation. Advanced age and comorbidities were often considered as main reasons to refuse SAVR. The annual mortality of untreated patients with severe AR is 10-20%. Pure native AR is always an exclusion criterion in all randomized controlled trials on transcatheter aortic valve implantation (TAVR) because the specific anatomical features can preclude adequate valve implantation. Several small, retrospective studies showed that off-label use of TAVR appears to be a feasible treatment choice for AR patients at high risk for SAVR. The present study aims to investigate the use of TAVR in AR patients.

Inclusion criteria

• 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;
• Severe aortic valve regurgitation, and mean pressure gradient < 20mmHg; Annular perimeter ≤ 85 mm;
• The ratio of the perimeter of the left ventricular outflow tract 4mm to the perimeter of the valve annulus is 0.95-1.05;
• 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:

• Severe aorta calcification or active ascending aorta atherosclerotic plaque
• History of mediastinum radiotherapy
• Past mediastinitis
• Presence of unobstructed coronary bypass implants
• Previous more than two cardiothoracic surgeries
• Liver cirrhosis
• Other surgical risk factors

Exclusion criteria

• Age < 60 years old;
• Ascending aorta diameter >45mm;
• Coronary multi-vessel disease (SYNTAX score >32);
• Life expectancy <1 year;
• Left ventricular ejection fraction <30%;
• Acute myocardial infarction within 30 days;
• Allergies or contraindications to related drugs (aspirin, clopidogrel, warfarin, or contrast agents);
• Other situations judged by the researcher as unsuitable for participating in the study.