Early 6 months usage of single anTiplAtelet OR anTicoAgulant followed by single antiplatelet after transcatheter aortic valve replacement: protocol for a multicentre, open-label, randomised controlled clinical trial.

INTRODUCTION: The strategy for initiating antithrombotic therapy to prevent bioprosthetic valve thrombosis (BPVT) after transcatheter aortic valve replacement (TAVR) remains uncertain. There is still lacking evidence on the efficacy and safety of early 6 months usage of single-antiplatelet therapy (SAPT) or oral anticoagulant (OAC) after TAVR in patients without anticoagulant indications. METHODS AND ANALYSIS: This is a multicentre, randomised controlled, open-label trial, and 650 patients undergoing TAVR from 13 top TAVR centres in China will be recruited. Each eligible participant will be randomly assigned to two groups (1:1 ratio) as (1) SAPT (aspirin 75-100 mg for 6 months) group or (2) OAC group (warfarin, therapeutic international normalised ratio at 1.8-2.5 for 6 months), both followed by sequential aspirin 75-100 mg for 6 months. Participants in both groups will be invited for three follow-up visits of 1, 6 and 12 months after discharge. We will use both the net clinical benefit endpoint (composite of all-cause mortality, myocardial infarction, stroke/transient ischaemic attacks, peripheral artery thrombosis, intracardiac thrombosis and major bleeding and disabling or life-threatening bleeding) and the BPVT endpoint evaluated by four-dimensional CT as our primary endpoints. P value of <0.05 of two-sided test will be considered statistically significant. ETHICS AND DISSEMINATION: The present study was approved by the Institutional Review Boards at Fuwai Hospital, National Center for Cardiovascular Diseases of China (Approval No. 2023-1947). All patients will be informed of the details of the study and will sign an informed consent prior to inclusion in the study. Results of this study will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT05375474.