A prospective, single arm clinical investigation evaluating safety and effectiveness/performance of the Microport CardioFlow VitaFlowTM II - Transcatheter Aortic Valve System for the treatment of symptomatic severe aortic stenosis via transcatheter access in increased surgical risk patients

This is a prospective, multicenter, single arm and controlled clinical investigation compared to recent historical results. The purpose is to evaluate the safety, performance and efficacy of the VitaflowTM II Transcatheter Aortic Valve system.

The entire system including valve system, delivery system and introducer system. We will implant the valve system into subjects and followed up them for 5 years after the procedure. This clinical trial will be conducted in 15 sites in Europe.

Inclusion Criteria:

1. Subjects of age > 18 years

2. Subjects suffering from severe aortic valve stenosis, including bicuspid and tricuspid valves, defined as follows:

   High-gradient aortic stenosis (mean pressure gradient across aortic valve >40 mmHg or peak velocity ≥4.0 m/s.

3. Subject has symptomatic valve stenosis presenting with NYHA ≥ Class II

4. Subjects with a documented heart team agreement of increased surgical risk as described in the population

5. ECG-gated multi-slice computed tomographic (MSCT) measurements determined an aortic annulus or supra-annular diameter ≥17 and ≤29mm. Findings of TTE, TEE and conventional aortography should be integrated in the anatomic assessment, when performed

6. Patient deemed eligible by Centralised Case Review Committee (CRC) assessment recommends VitaFlow™ II Transcatheter Aortic Valve System implantation

7. Subject can understand the purpose of the clinical investigation, has signed voluntary the informed consent form and is agreeing to the scheduled follow up requirements

Exclusion Criteria:

1. Arterial aorto-iliac-femoral axis unsuitable for transfemoral access as assessed by conventional angiography and/or multi-detector computed tomographic angiography (access vessel diameter incompatible with a 19 to 22F OD delivery system with integrated sheath or 21 to 24F OD sheath)
2. Aortic root anatomy condition or lesion preventing implantation or access to the aortic valve
3. Non-calcific acquired aortic stenosis
4. Native unicuspid aortic valve or congenital aortic abnormality (except for bicuspid aortic valve) not permitting TAVI
5. Previous implantation of heart valve in any position
6. Severe aortic regurgitation (>3+)
7. Severe mitral regurgitation (>3+)
8. Severe tricuspid regurgitation (>3+)
9. Severe left ventricular (LV) dysfunction (left ventricular ejection fraction < 30%)
10. Echocardiographic evidence of intracardiac mass, thrombus or vegetation
11. Multi-vessel coronary artery disease with a Syntax score or residual Syntax score > 22 and/or unprotected left main coronary artery.
12. Cardiogenic shock manifested by low cardiac output, vasopressor dependence, or mechanical hemodynamic support
13. Untreated cardiac conduction disease in need of pacemaker implantation
14. Uncontrolled atrial fibrillation (resting heart rate > 120bpm)
15. Active and/or suspicion of endocarditis or ongoing sepsis
16. Blood dyscrasias defined as: leukopenia (WBC<1000 mm3), thrombocytopenia (PLT<50,000 cells/mm3), history of bleeding diathesis or coagulopathy, or hypercoagulable states
17. Evidence of an acute myocardial infarction ≤ 1 month (30 days) before signing informed consent
18. Any need for emergency surgery
19. Recent (within 6 months of signing informed consent) cerebrovascular accident (CVA) or transient ischemic attack (TIA)
20. Symptomatic carotid or vertebral artery disease or successful treatment of carotid stenosis within 30 days prior to signing informed consent
21. Any active bleeding that precludes anticoagulation
22. Liver failure (Child-C)
23. End-stage renal disease requiring chronic dialysis or creatinine clearance < 20cc/min
24. Pulmonary hypertension (systolic pressure >80mmHg)
25. Severe chronic pulmonary disease (COPD) demonstrated by an expiratory volume (FEV1) < 750cc
26. Refusal of blood transfusion
27. A known hypersensitivity or contraindication to all anticoagulation/antiplatelet regimens (or inability to be anticoagulated for the index procedure), to nitinol, to dairy products, to polyethylene terephthalate (PET) or contrast media
28. Any medical, social or psychological condition that in the opinion of the investigator precludes the subject from giving appropriate consent or adherence to the required follow up procedures
29. Currently participating in another drug or device trial (excluding registries) for which the primary endpoint has not been assessed
30. Estimated life expectancy of less than 12 months
31. For female - pregnancy or intention to become pregnant prior to completion of all follow up procedures
32. Inability to comply with the clinical investigation follow-up or other clinical investigation requirements

This is an internal clinical research, the detail data won't be shared with other researcher before our product come into the market.