An investigator-sponsored pragmatic randomized controlled trial of AntiCoagulation vs AcetylSalicylic Acid after Transcatheter Aortic Valve Implantation: Rationale and design of ACASA-TAVI

Abstract

Background The optimal antithrombotic therapy after transcatheter aortic valve implantation (TAVI) is unknown. Bioprosthetic valve dysfunction (BVD) is associated with adverse outcomes and may be prevented by anticoagulation therapy. A dedicated randomized trial comparing monotherapy NOAC to single antiplatelet therapy has not been performed previously. We hypothesize that therapy with any anti-factor Xa NOAC will reduce BVD compared to antiplatelet therapy, without compromising safety. Methods ACASA-TAVI is a multicenter, prospective, randomized, open-label, blinded endpoint, all-comers trial comparing a monotherapy anti-factor Xa NOAC strategy (intervention arm) with a single antiplatelet therapy strategy (control arm) after successful TAVI. Three-hundred and sixty patients without indication for oral anticoagulation will be randomized in a 1:1 ratio to either apixaban 5 mg twice per day, edoxaban 60 mg daily, or rivaroxaban 20 mg daily for 12 months followed by acetylsalicylic acid 75 mg daily indefinitely, or to acetylsalicylic acid 75 mg daily indefinitely. The 2 co-primary outcomes are (1) incidence of Hypo-Attenuated Leaflet Thickening (HALT) on 4-dimensional cardiac CT at 12 months, and (2) a Safety Composite of VARC-3 bleeding events, thromboembolic events (myocardial infarction and stroke), and death from any cause, at 12 months. Results The first 100 patients had a mean age of 74 ± 3.6 years, 33% were female, the average body-mass index was 27.9 ± 4.4 kg/m2, and 15% were smokers. A balloon-expanded valve was used in 82% and a self-expandable valve in 18%. Conclusions The trial is planned, initiated, funded, and conducted without industry involvement.