Balloon vs. Self Expanding Transcatheter Valve for Degenerated Bioprosthesis

Transcatheter aortic valve implantation (TAVI) serves a growing spectrum of patients with symptomatic severe aortic stenosis (AS). Approximately 80% of surgical aortic valve replacements are performed using a bioprosthesis. Durability of surgical bioprostheses varies according to patient age at the time of implantation, prosthesis type and size, among other factors. TAVI has become an established treatment option for patients with a degenerated surgical aortic bioprosthesis. The time from index surgical aortic valve replacement (SAVR) to bioprosthetic valve degeneration is typically 8-10 years. TAVI in this setting has shown favorable outcomes. Balloon-expandable and self-expanding transcatheter heart valves (THVs) can both be used for the treatment of a degenerated surgical aortic bioprosthesis and have specific advantages and limitations. Valve-in-valve TAVI may be associated with coronary obstruction, THV migration, paravalvular regurgitation, and prosthesis-patient mismatch.

Objective:

To compare valve-in-valve TAVI with balloon-expandable SAPIEN/MYVAL THV series versus the self-expanding EVOLUT THV series. The primary analysis evaluates device success at 30 days in the primary cohort. Continued enrollment will additionally support a secondary comparison of the safety and efficacy of the SAPIEN and MYVAL THV series.

Study design: International multicenter randomized study with 1:1 randomization to TAVI with the EVOLUT THV series or the SAPIEN/MYVAL THV series.

Study population:

The primary cohort comprises 440 patients with a failing surgical aortic bioprosthesis (aortic stenosis with or without aortic regurgitation) selected for transfemoral TAVI by heart-team consensus. Enrollment of the primary cohort has been completed.

The continued-enrollment cohort comprises 160 additional patients and will increase the total study population to 600 patients, with a target distribution of 300 patients treated with the EVOLUT THV series, 150 with the SAPIEN THV series, and 150 with the MYVAL THV series.

Investigational intervention:

Transfemoral valve-in-valve TAVI with a balloon-expandable SAPIEN or MYVAL THV series or a self-expanding EVOLUT THV series.

Main study parameters/endpoints:

1. Primary endpoint is device success at 30 days

Defined by: * Absence of procedural mortality; AND * Technical success at exit from the procedure room defined as freedom from mortality, successful access, delivery of the device and retrieval of the delivery system, correct positioning of a single prosthetic heart valve into the proper anatomical location, and freedom from surgery or intervention related to the device or to a major vascular or access-related, or cardiac structural complication; AND * Intended performance of the prosthetic heart valve (no severe prosthesis-patient mismatch and mean aortic valve gradient \<20 mmHg or peak velocity \<3 m/s, Doppler velocity index ≥0.25, and no moderate or severe prosthetic valve regurgitation).

Severe prosthesis-patient mismatch is defined as an indexed effective orifice area (EOAi) ≤0.65 cm²/m² (≤0.55 cm²/m² if BMI ≥30 kg/m²). 2. Safety endpoint at 1 year defined by the composite of all-cause death, disabling stroke, rehospitalization for heart failure, or valve-related problems. 3. Secondary objective is comparison of the safety and efficacy of the SAPIEN versus MYVAL THV series, including the incidence of moderate or severe prosthesis-patient mismatch.

The continued-enrollment cohort is designed to support this comparison.