A Prospective, Multicenter, Observational Study of the Safety and Efficacy of Emergency Transcatheter Aortic Valve Replacement in Patients With Severe Aortic Stenosis

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. The prognosis of patients with severe aortic stenosis (AS) is extremely poor in emergency, and the mortality of traditional balloon angioplasty (PBAV) is high. As a new treatment method, emergency TAVR needs multi-center data to verify its safety and effectiveness. Based on the preliminary results of a single center, this study was extended to multiple centers in China, aiming at providing high-level evidence, helping to optimize the implementation strategy of emergency TAVR, and promoting its wide application in patients with severe aortic stenosis, thus improving the clinical prognosis and quality of life of patients. This study is a prospective, multi-center clinical study, and 35 patients are planned to be enrolled. All participants are followed up before discharge, 30 days, 6 months and 12 months after valve implantation, and the research unit independently manages data, including data collection, collation and statistical analysis. 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. The selection criteria are: patients with severe aortic stenosis diagnosed by medical treatment; Meet one of the emergency TAVR indications (shock, persistent ventricular tachycardia or ventricular fibrillation, unstable angina pectoris or chronic heart failure requiring mechanical circulatory assistance devices, etc.); Voluntary participation and signing of informed consent. The main exclusion criteria are: aortic root anatomy and lesions are not suitable for artificial valve implantation; Anatomical morphology or vascular diseases that affect the instrument approach; Left ventricular outflow tract obstruction; Primary dilated cardiomyopathy; Thrombosis in left ventricle; Patients who cannot receive anticoagulant or antiplatelet therapy, etc. The statistical methods used are descriptive analysis, Kaplan-Meier survival analysis and Cox proportional hazard model (SAS 9.4). Following the Helsinki Declaration, China's Quality Management Standard for Clinical Trials of Medical Devices and ISO 14155:2011, all patients signed informed consent forms with the approval of the Ethics Committee.