Clinical Research Directory

Inclusion Criteria: 1. Patients with severe aortic stenosis diagnosed at the clinic: peak transvalvular flow velocity ≥4.0m/s, or mean transvalvular pressure difference ≥40mmHg(1 mmHg=0.133kPa), or aortic valve orifice area \< \<0.8cm2 (or effective aortic valve orifice area index \< 0.5 cm2/m2); 2. Meet one of the following emergent TAVR indications: 1\) Shock; 2) Combined with persistent ventricular tachycardia or ventricular fibrillation; 3) Difficulty in improving unstable angina pectoris or chronic heart failure requiring mechanical circulatory assistance with drugs; 4) Cardiopulmonary resuscitation is required for cardiac arrest; 3. Patients who can understand the purpose of the study, voluntarily participate in and sign the informed consent form, and are willing to accept the relevant examinations and clinical follow-up. Exclusion Criteria: 1. Aortic root anatomy and lesions are not suitable for prosthetic valve implantation; 2. Anatomic morphology or vascular diseases affecting the instrument approach; 3. Left ventricular outflow tract obstruction; 4. Primary dilated cardiomyopathy; 5. Thrombus in the left ventricle; 6. Patients who are unable to receive anticoagulation or antiplatelet therapy; 7. Allergy to or resistance to Nitinol; 8. Active stage of infective endocarditis or other infection that the researcher believes affects the operation; 9. Severe disability senile dementia; 10. Patients with a life expectancy of less than half a year; 11. The investigator determined that the patient or family had poor compliance or declined to complete the study as required.