For the roughly one in five TAVR procedures now performed inside a previously implanted bioprosthetic valve, the blood-thinning regimen chosen at discharge may matter as much as the procedure itself — yet until now, real-world U.S. practice has been poorly mapped. This large registry analysis fills a critical evidence gap for a growing, complex patient population.
Drawing on the STS/ACC Transcatheter Valve Therapy Registry, investigators analyzed 18,414 patients who underwent valve-in-valve (ViV) TAVR between January 2015 and March 2024, excluding those with pre-existing indications for dual antiplatelet therapy (DAPT) or oral anticoagulation (OAC). Three discharge strategies were compared: single antiplatelet therapy (SAPT, 27.3%), DAPT (53.5%), and OAC-based therapy (19.2%). A notable secular shift emerged over the study window — DAPT declined significantly while SAPT rose to become the dominant approach by early 2024. One-year outcomes including all-cause mortality, stroke, and bleeding were assessed via inverse probability of treatment weighting in a sub-cohort followed through January 2023.
The clinical and mechanistic rationale for this strategic drift is worth unpacking. ViV TAVR creates a smaller effective orifice than native-valve TAVR, increasing turbulent flow and shear stress — conditions that theoretically favor both platelet activation and leaflet thrombosis. Historically, DAPT was borrowed from coronary stenting logic, but ViV hemodynamics differ considerably. Emerging data from ATLANTIS and other trials have begun tilting guidelines toward OAC for leaflet thrombosis prevention in standard TAVR, yet uptake in ViV remained low here at under 20%. The enormous operator-level and site-level variability in strategy selection — a central finding of this analysis — underscores the absence of robust randomized evidence specific to ViV scenarios. As a registry study, causal inference is limited by unmeasured confounding; the weighting approach mitigates but cannot eliminate selection bias. Nevertheless, the dataset's scale and duration make it the most comprehensive U.S. portrait of ViV antithrombotic practice to date, and it will likely inform upcoming randomized trial design.