Background:~Transcatheter aortic valve implantation (TAVI) is an established and valuable treatment option for patients with severe symptomatic aortic stenosis and at increased risk for surgical aortic valve replacement (SAVR). The use of TAVI is rapidly expanding worldwide and the indications for TAVI are widening into lower risk populations in view of favorable outcomes among high and intermediate risk patients. Many novel devices are currently developed or established devices undergo design reiterations to address limitations, such as vascular access complications, paravalvular regurgitation, and atrio-ventricular conductance disturbances. However, device comparisons by use of randomized trials are scarce in particular for newer generation transcatheter valves.~The Symetis ACURATE neo/TF, a self-expandable transcatheter valve delivered via transfemoral access, gained Conformité Européenne (CE) marking in September 2014 after showing favorable procedural and short term results. The SCOPE I trial will compare its performance to the balloon-expandable Edwards SAPIEN 3, a widely used and well-established transcatheter heart valve of the second generation, in a randomized fashion.~Objectives:~The primary objective is the comparison of the Symetis ACURATE neo/TF to the Edwards SAPIEN 3 transcatheter aortic bioprosthesis with regard to early safety and clinical efficacy at 30 days. Secondary objectives involve the comparison between the two devices with regard to secondary clinical and echocardiographic endpoints at 30 days, 1 year and 3 years.~Methods:~Sample Size: Based on an anticipated incidence proportion of 22% for the primary non-hierarchical composite endpoint at 30 days in both treatment arms, a non-inferiority margin of 7.7%, a power of 80%, a one-tailed significance level of α = 0.05, and a low attrition rate, the total required sample size amounts to 730 patients.~Design: Patients will be allocated to the Symetis ACURATE neo/TF or the Edwards SAPIEN 3 bioprosthesis at a 1:1 ratio by means of a randomly permuted block randomisation stratified on study center and Society of Thoracic Surgeons' predicted risk of mortality score (STS-PROM) strata (< 3%, ≥ 3 to < 8%, ≥ 8%).~Analysis: Estimates of the risk-differences between the two treatment arms with regard to the primary endpoint will be pooled over the predefined STS-PROM strata by means of the Cochran-Mantel-Haenszel method and Wald-type confidence limits will be calculated using the Sato variance estimator. The non-inferiority assumption will be tested at a one-sided significance level with a type I error rate (α) = 0.05. The analysis of the primary composite endpoint will be conducted according to the intention-to-treat (ITT) and the per protocol (PP) principle and non-inferiority should be claimed only if met by both.~In case non-inferiority is established, a superiority analysis will be performed using a two-tailed significance level with a type I error rate of α = 0.05. Further secondary analyses will evaluate between group differences in relation to demographic, clinical, procedural, functional and imaging characteristics. Pre-specified subgroup analyses will be conducted by use of appropriate interaction tests contrasting categories of sex, STS-PROM score (< 3%, ≥ 3 to < 8%, ≥ 8%), left ventricular ejection fraction (< 50% vs. ≥ 50%), and native aortic valve eccentricity index (≤ 0.25 vs. > 0.25).
Transcatheter aortic valve implantation (TAVI) is an established treatment option for patients with severe symptomatic aortic stenosis and at increased risk for surgical aortic valve replacement (SAVR). Many novel devices are currently being developed and established transcatheter heart valves undergo design reiterations to address limitations and reduce complication rates associated with the device and implantation procedure. However, device comparisons by use of randomized trials are scarce in particular for newer generation transcatheter valves. The aim of this study is to assess non-inferiority of the self-expandable Symetis ACURATE neo/TF in comparison to the balloon-expandable Edwards SAPIEN 3 transcatheter aortic valve bioprosthesis with regard to early safety and clinical efficacy at 30 days.