To evaluate the safety and effectiveness of the Transcatheter aortic valve and retrievable delivery system (VitaFlow Liberty®) for the treatment of severe bicuspid aortic valve (BAV) stenosis.

Transcatheter aortic valve replacement (TAVR) has emerged as the first-line treatment for symptomatic severe AS currently, while TAVR for bicuspid aortic valve (BAV) stenosis has not been well demonstrated in randomized controlled trials, thus more randomized controlled studies of TAVR vs. SAVR are still needed to provide strong evidence that TAVR treatment for patients with BAV stenosis has good safety and effectiveness.

This study is a prospective, international multicenter, randomized controlled, non-inferiority clinical study, in which the study device (VitaFlow Liberty®) for TAVR is to be demonstrated as non-inferior to the control device (a commercially available surgical bioprosthetic valve) for SAVR in terms of the incidence of composite endpoint events (all-cause mortality, all strokes and re-hospitalizations) at 12 months postoperatively.

In this study, 452 eligible subjects will be randomly assigned to the study group (n=226) or the control group (n=226) in a 1:1 ratio. The subjects in study group will be treated with the TAVR surgery using the study device (VitaFlow Liberty®) , while the subjects in control group will be treated with the SAVR surgery using the control device (a commercially available surgical bioprosthetic valve), and clinical follow-ups will be performed at discharge (or 7 days after surgery), 30 days, 6 months, 12 months, and 2, 3, 4, 5 years after surgery, respectively.

Inclusion Criteria:

1. Subject aged ≤ 75 years;
2. With symptomatic severe bicuspid aortic stenosis, defined as: peak flow velocity ≥ 4.0m/s, or mean trans-aortic pressure gradient ≥ 40mmHg, or aortic orifice area (AVA) ≤ 1.0cm2 (or AVA index ≤ 0.6cm2/m2) confirmed by echocardiography；
3. New York Heart Association (NYHA) cardiac function classification ≥ Class II;
4. With an intermediate or low risk of surgical procedures (STS score ≤8%) assessed by the local heart team;
5. Voluntarily participate in this study and sign the informed consent form.

Exclusion Criteria:

1. Known allergy or resistance to study device and control device components such as nitinol or contrast media;
2. Known contraindication or allergy to anticoagulant or antiplatelet medications and inability to tolerate the anticoagulant or antiplatelet therapy;
3. Known presence of active infective endocarditis or other active infection;
4. Known presence of severe vascular disease that precludes safe implantation of the prosthetic valve;
5. Ascending aorta width ≥50mm;
6. Previous prosthetic valve implantation (mechanical or bioprosthetic) in any heart place;
7. The aortic root anatomy not suitable for transcatheter aortic valve implantation confirmed by preoperative imaging (including aortic root calcification that influence the sufficient dilatation of the rposthetic valve);
8. Intracardiac mass, left ventricular or left atrial thrombus, vegetations confirmed by preoperative echocardiography;
9. Acute myocardial infarction (defined as Q-wave MI or non-Q-wave MI) within 30 days prior to surgery;
10. Invasive therapeutic cardiac surgery within 30 days prior to surgery (except for temporary pacemaker or implantable cardioverter-defibrillator implantation);
11. Clinically diagnosed stroke or TIA within 3 months prior to surgery;
12. Gastrointestinal bleeding requiring hospitalization or transfusion therapy or other clinically significant bleeding or coagulation disorders within 3 months prior to surgery, which preclude the required antiplatelet therapy in the study;
13. Comorbid with severe native coronary artery lesions that require revascularization therapy;
14. Comorbid with severe mitral or tricuspid regurgitation;
15. Comorbid with cardiogenic shock or hemodynamic instability requiring support from positive inotropic agents or mechanical ventilation or mechanical cardiac assistance;
16. Comorbid with severe left ventricular dysfunction (defined as left ventricular ejection fraction LVEF <20%);
17. Comorbid with end-stage renal diseases requiring chronic dialysis;
18. Comorbid with blood dyscrasias defined as leukopenia (white blood cell count < 3×109/L), thrombocytopenia (platelet count < 50×109/L), history of bleeding diathesis or coagulopathy, or hypercoagulable states;
19. Subjects corresponding to the criteria of a vulnerable population (including patients who are unable to fully understand all aspects of the study, patients lacking capacity in the informed consent procedure and patients with dementia and cognitive impairment);
20. Female subjects known to be pregnant or lactating;
21. Life expectancy is less than 12 months as assessed by the investigator;
22. Subject is participating in or planning to participate in other drug or device clinical studies within 12 months postoperatively;
23. Any other condition that, at the discretion of investigator or heart team, may preclude the subject's safe participation in the study.