BACKGROUND: Redo surgical aortic valve replacement (rSAVR) has for long been the therapeutic reference standard for degenerated surgical aortic bioprostheses. Valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) has emerged as an alternative for patients at high surgical risk due to its lower invasiveness. The long-term clinical efficacy of ViV-TAVR in patients at low to intermediate surgical risk remains unknown. METHODS AND RESULTS: To compare clinical outcomes of redo surgical aortic valve replacement versus ViV-TAVR in low- to intermediate-risk patients with degenerated surgical aortic bioprostheses. REPEAT (Repeat Intervention for Deteriorated Surgical Bioprosthetic Aortic Valves) is an investigator-initiated, international, multicenter, randomized, parallel, open-label trial. A total of 890 patients aged <
75 years with a failed surgical aortic bioprosthesis due to structural valve degeneration and low to intermediate surgical risk (ie, Society of Thoracic Surgeons predicted risk of death of <
8%) will be randomly assigned in a 1:1 ratio to either redo surgical aortic valve replacement or ViV-TAVR. The primary end point of REPEAT is a composite of all-cause death, stroke (including both disabling and nondisabling), myocardial infarction, and rehospitalization for heart failure or aortic valve reintervention at 5 years, based on Valve Academic Research Consortium-3 definitions. Secondary end points include each of the individual components of the primary composite end point, Valve Academic Research Consortium-3-based conduction disturbances and arrhythmia, Valve Academic Research Consortium-3-based wound and bleeding complications, functional status (ie, 6-minute walk test, Kansas City Cardiomyopathy questionnaire), and treatment costs. CONCLUSIONS: The REPEAT trial has been designed to test the hypothesis that redo surgical aortic valve replacement is superior to ViV-TAVR regarding clinical outcomes at 5 years in patients with degenerated surgical aortic bioprostheses and low to intermediate surgical risk.