To observe the clinical outcomes of the different valve sizing strategies treating type-0 Bicuspid Aortic Stenosis (BAS) with self-expandable transcatheter aortic valve implantation (TAVI) valve, compared with those of a standard sizing strategy of normal Tricuspid Aortic Stenosis(TAS).

BACKGROUND: From our current clinical experience, investigators mostly choose the smaller self-expandable transcatheter valve for type-0 BAS than that for TAS, combined with "balloon sizing" strategy. But no prospective and randomized studies show the rationality and clinical outcomes of different sizing strategies of type-0 BAS with self-expandable transcatheter valve.

AIM: To observe the clinical outcomes of the different valve sizing strategies treating type-0 BAS with self-expandable transcatheter aortic valve implantation (TAVI) valve, compared with those of a standard sizing strategy of normal TAS.

POPULATION: All patients with severe degenerative aortic valve stenosis referred for aortic valve intervention will be screened for study eligibility. To be included subjects must be 65 years or older, anatomical and technical eligible for both interventions, expected to survive more than 1 year after the intervention, and able to provide written informed consent. Study exclusion criteria include isolated aortic valve regurgitation or other significant valve disease, unstable preoperative condition.

DESIGN: The project is a multicenter randomized clinical trial. Patients of type-0 BAS fulfilling all inclusion and no exclusion criteria will be randomized into either Down sizing group or Standard sizing group. Randomization will be 1:1 with 53 subjects in each group. Meanwhile patients of TAS fulfilling all inclusion and no exclusion criteria will be included as a Standard group in this study. Screening and inclusion will commence in September 2015. Inclusion is expected to last 3 years, and subjects will be followed for 5 years.

Inclusion Criteria:

1. Patients with symptomatic severe aortic stenosis (echocardiographic criteria: AV effective orifice area (EOA) of < 1 cm2, mean AV gradient of > 40 mmHg, or AV peak systolic velocity of > 4.0 m/s; NYHA-class II or greater, angina pectoris, or syncope)
2. Subject has been informed of the nature of the study, agrees to its provisions and has provided written informed consent.
3. The subject agrees to comply with specified follow-up evaluations and to return to the investigational site where the procedure was performed.
4. Patients are technical and anatomical eligible for interventions

Exclusion Criteria:

1. A known hypersensitivity or contraindication to any of the following which cannot be adequately pre-medicated:

   • Aspirin
   • Heparin (HIT/HITTS) and bivalirudin
   • Nitinol (titanium or nickel)
   • Ticlopidine and clopidogrel
   • Contrast media

2. Subject refuses a blood transfusion.

3. Other medical, social, or psychological conditions that in the opinion of an Investigator precludes the subject from appropriate consent.

4. Native aortic annulus size < 20 mm or > 29 mm per the baseline diagnostic imaging.

5. Life expectancy is less than one year