The purpose of this clinical study is to evaluate the effectiveness and safety of the transcatheter aortic valve system in the treatment of patients with severe aortic stenosis disease who are at high or prohibitive surgical risk.

This study is a prospective, multicenter, single-arm, clinical study.

Inclusion Criteria:

1. Age ≥ 65;
2. Patients with symptomatic aortic valve regurgitation diseases, and New York Heart Association (NYHA) ≥ II;
3. Subject must have Society of Thoracic Surgeons (STS) score ≥8% or have been evaluated as inoperable by the surgical team [defined as rate of death #50% within 30 d post-surgery or accompanied with irreversible occasions of other factors prevent surgeries (such as heavily calcified (porcelain) ascending aorta, weakness, chest malformation, liver dysfunction, pulmonary dysfunction and so on ); (Note: age of inoperable patients can be expanded to ≥ 50);
4. Aortic valve anatomy is suitable for TAVR evaluated by the investigators;
5. Patients who can sign informed consent form, and are willing to accept relevant examinations and clinical follow-ups.

Exclusion Criteria:

1. Active endocarditis;
2. Acute myocardial infarction or coronary revascularization occurred within 1 month before procedure;
3. Cerebrovascular accident (CVA) occurred within 30 days before procedure;
4. The echocardiogram indicates the presence of mass, thrombus or vegetation in left ventricle and left atrium;
5. Hypertrophic obstructive cardiomyopathy;
6. Other valve diseases that need interventions;
7. Previous aortic valve implantation (mechanical or biological);
8. Allergic to Nickel-titanium alloys or contrast agents or cattle-originated products;
9. Known allergy or contraindication to all anticoagulation, or anticoagulation can not be used during the TAVR;
10. In presence one of the following (from selection to the day of procedure index): a other diseases that may shorten life expectancy to less than 12 months (recurrent or metastatic cancer, congestive heart failure); b drug abuse (such as cocaine, heroin and so on); c planned additional operations that may result in incompliance or data confusion;
11. Stenosis of common carotid artery, internal carotid artery or vertebral artery #70%;
12. Severe left ventricular dysfunction, left ventricular ejection fraction (LVEF) <20%;
13. Hepatic encephalopathy or acute active hepatitis;
14. Receiving hemodialysis;
15. Bleeding tendency or history of coagulopathy or refuse to receive transfusion;
16. Active gastrointestinal (GI) ulcer or bleeding;
17. Severe dementia;
18. Patients who need emergency surgery for any reason;
19. Patients are participating in other drugs or medical devices clinical trial;
20. Pregnant or plan to be pregnant, or are taking estrogen or estrogen-like drugs (Women suspected of pregnancy must have a negative serum or urine test for human villous gonadotropin prior to enrollment in the study);
21. Other inappropriate occasions according to the investigators.](streamdown:incomplete-link)