Trends and Outcomes of Antithrombotic Strategies for Valve-in-Valve TAVR

BACKGROUND The optimal antithrombotic strategy after valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) for degenerated aortic bioprostheses remains undetermined, and current practice patterns in the United States are not well characterized. OBJECTIVES The aim of this study was to evaluate temporal trends, variability, and clinical outcomes of antithrombotic strategies in patients undergoing ViV TAVR in the United States. METHODS Patients who underwent ViV TAVR between January 2015 and March 2024 in the Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapy) Registry were included, excluding those with established indications for dual antiplatelet therapy (DAPT) or oral anticoagulation (OAC). Antithrombotic strategies were categorized as single antiplatelet therapy (SAPT), DAPT, or OAC-based therapy on discharge. In the cohort eligible for 1-year assessment (January 2015 to January 2023), the endpoints of all-cause mortality, stroke, and bleeding at 1 year were compared using inverse probability of treatment weighting. RESULTS A total of 18,414 patients were included (SAPT, 27.3%; DAPT, 53.5%; OAC-based therapy, 19.2%). Between the first quarter of 2015 and the first quarter of 2024, DAPT use significantly declined, whereas SAPT use increased, becoming the predominant strategy. OAC-based therapy remained the least used. Practice patterns varied widely among operators and sites, with proportion of each antithrombotic strategy ranging from nearly 0% to 100%. After adjustment, DAPT and OAC-based therapy were not associated with differences in all-cause mortality (DAPT: adjusted HR HRadj: 0.91 95% CI: 0.74-1.11; OAC-based therapy: HRadj: 1.14 95% CI: 0.89-1.46), stroke (DAPT: HRadj: 0.98 95% CI: 0.73-1.30; OAC-based therapy: HRadj: 1.09 95% CI: 0.76-1.55), or bleeding (DAPT: HRadj: 0.86 95% CI: 0.71-1.04; OAC-based therapy: HRadj: 0.88 95% CI: 0.70-1.11) compared with SAPT at 1 year. CONCLUSIONS Analysis of a national U.S. registry revealed wide variation in antithrombotic regimens following ViV TAVR, likely reflecting the absence of robust evidence to guide treatment decisions. Although no differences in outcomes were identified in this large retrospective analysis, a randomized trial with long-term follow-up is necessary to inform optimal management in this growing patient population.