This trial consists of two parts. Part I, the Feasibility trial: 10-12 patients with severe aortic stenosis who meet inclusion/exclusion criteria and are at high surgical risk or not suitable for conventional surgical valve replacement are selected at no more than 5 centers for implantation of an aortic valve by transcatheter aortic valve replacement (KOKA-VALVE) to achieve treatment of aortic valve disease in subjects. All-cause mortality at 30 days after implantation is used as the primary endpoint, and the immediate postoperative device success and surgical success, major cardiovascular adverse events at 1 year after implantation, transvalvular pressure difference at 30 days and 12 months after implantation, degree of orifice regurgitation, degree of perivalvular leakage, improvement in NYHA cardiac function, and improvement in quality of survival are used as the secondary endpoints to supplementarily evaluate the safety and feasibility of this product. It also provides experience and reference for further Part II confirmatory trials and applications to ensure safe conduct of confirmatory trials. Subjects in the feasibility trial may continue to be followed up at 6 months after implantation and 12 months after implantation after completion of the one-month postoperative follow-up. All subjects will also continue to be followed up by telephone at 24, 36, 48, and 60 months after implantation.~Part II, the Confirmatory Trial: Designed with a prospective, multi-center, one-arm approach. 131 patients with severe aortic stenosis who meet inclusion/non-exclusion criteria and are at high surgical risk or unsuitable for conventional surgical valve replacement are implanted with an aortic valve by transcatheter aortic valve replacement (KOKA-VALVE) to achieve treatment of aortic valve disease in subjects. All-cause mortality at 30 days after implantation is used as the primary endpoint, and the immediate postoperative device success and surgical success, major cardiovascular adverse events at 1 year after implantation, transvalvular pressure difference at 30 days and 12 months after implantation, degree of orifice regurgitation, degree of perivalvular leakage, improvement in NYHA cardiac function, and improvement in quality of survival are used as the secondary endpoints to supplementarily evaluate the safety and feasibility of this product.~All patients will be followed up before discharge, 30 days, 6 months, and 12 months after implantation after product implantation. All subjects will be followed up by telephone at 24 months, 36 months, 48 months and 60 months after implantation.~The study will be conducted at multiple clinical trial sites nationwide, and 131 subjects will be enrolled in the confirmatory trial. The enrollment and treatment status of the subjects will be recorded during the study, and the subjects will be followed up before discharge, 6 months after implantation, and 12 months after implantation, and the data will be compiled for registration and declaration.~All subjects will be followed up by telephone at 24 months, 36 months, 48 months, and 60 months after implantation.
A Clinical Trial of the Transcatheter Aortic Valve Implantation System with a Prospective, Multi-Center, One-Arm Approach to Evaluate the Efficacy and Safety in the Treatment of Patients with Severe Aortic Stenosis