Comparative Analysis of Antithrombotic Strategies Following Valve-in-Valve Transcatheter Aortic Valve Implantation Using Real-World Registry Data

BACKGROUND: Valve-in-valve transcatheter aortic valve implantation is a less invasive alternative to redo surgery for failed surgical bioprostheses, but optimal antithrombotic management is uncertain. OBJECTIVES: To compare outcomes across antithrombotic regimens after valve-in-valve procedures in real-world practice. METHODS: In the Australasian Cardiac Outcomes Registry (2018-2025), 1,050 adults were grouped by discharge regimen: single antiplatelet therapy, dual antiplatelet therapy, oral anticoagulation, or oral anticoagulation plus antiplatelet therapy. Outcomes included 30-day and 12-month mortality, stroke/TIA, life-threatening or major bleeding, major adverse cardiac and cerebrovascular events, and echocardiographic valve performance. RESULTS: Thirty-day mortality was higher with oral anticoagulation (1.7%) and combination therapy (3.6%) than with single or dual antiplatelet therapy (both 0%; p < 0.001). The 30-day MACCE rate was greater with oral anticoagulation (4.5%) and combination therapy (4.4%) than with single (1.5%) or dual antiplatelet therapy (0.4%) (p = 0.003); stroke/TIA and bleeding were infrequent and similar across groups. At 12 months, MACCE remained highest with oral anticoagulation (11.8%) and combination therapy (10.7%) compared with single (5.0%) and dual antiplatelet therapy (3.2%) (p = 0.001). Mortality at 12 months was numerically higher with oral anticoagulation or combination therapy (5.2% and 4.4%) than with single or dual antiplatelet therapy (1.8% and 2.4%) (p = 0.116). At 30 days, transvalvular gradients were lower in patients receiving oral anticoagulation-containing regimens; however, no significant differences in gradients, valve area, ejection fraction, or regurgitation were observed at 12 months. In multivariable analysis, combination therapy was independently associated with higher odds of 12-month MACCE compared with SAPT (OR 2.76, 95% CI 1.03-7.37; p = 0.043). Higher STS score and greater frailty were also independently associated with 12-month MACCE. CONCLUSIONS: In this observational cohort of patients undergoing valve-in-valve TAVI, oral anticoagulation-containing regimens were associated with higher early mortality and higher 12-month MACCE rates than antiplatelet-only strategies. However, these associations should be interpreted cautiously, as they likely reflect in part the greater baseline comorbidity burden of patients prescribed anticoagulation rather than a direct treatment effect. No sustained haemodynamic benefit was observed at 12 months. Individualised antithrombotic therapy and prospective randomised studies are warranted.