The research name of this project is: A prospective, multicenter and observational study on the safety and effectiveness of emergency transcatheter aortic valve replacement (TAVR) in the treatment of patients with severe aortic stenosis. It is a prospective, multi-center clinical study, and 35 cases are planned to be enrolled and followed up for 12 months (before discharge, 30 days, 6 months and 12 months). The research instruments used are VitaFlow Liberty® transcatheter aortic valve and recoverable delivery system. The purpose of this study is to evaluate the safety and effectiveness of emergency TAVR in patients with severe aortic stenosis. The main end point is the cumulative all-cause mortality 12 months after operation, and the secondary end points mainly include adverse cerebrovascular events (MACCE), acute renal injury, implantation rate of permanent pacemaker and valve function.
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);
Aortic root anatomy and lesions are not suitable for prosthetic valve implantation;
Anatomic morphology or vascular diseases affecting the instrument approach;
Left ventricular outflow tract obstruction;
Primary dilated cardiomyopathy;