Low-Dose Rivaroxaban to Prevent Left Ventricular Thrombosis After Anterior Myocardial Infarction

Importance Anterior acute myocardial infarction is associated with increased risk of left ventricular (LV) thrombus. The benefit and risk of adding an oral anticoagulant to dual antiplatelet therapy (DAPT) in preventing LV thrombus remain uncertain. Objective To determine whether the addition of low-dose rivaroxaban to DAPT reduces the incidence of LV thrombus at 1 month in patients with anterior ST-segment elevation myocardial infarction (STEMI). Design, Setting, and Participants This multicenter, open-label, blinded–end point randomized clinical trial was performed in 29 centers in France. The trial was nested in the ongoing FRENCHIE (French Cohort of Myocardial Infarction Evaluation) registry. Between October 2021 and January 2023, patients with anterior STEMI were enrolled. The last date of participant follow-up was in March 2023. Data analysis was performed from September 2024 to July 2025. Interventions Patients were randomized to receive either DAPT plus rivaroxaban, 2.5 mg, twice daily for 4 weeks (n = 283) or DAPT alone (aspirin ≤100 mg per day and either clopidogrel, 75 mg per day, or ticagrelor, 90 mg twice a day n = 277), as soon as possible following completion of the initial percutaneous coronary intervention or angiography procedure. Main Outcomes and Measures The primary end point was presence of LV thrombus on contrast-enhanced cardiac magnetic resonance imaging at 1 month. Results Among 560 patients with anterior STEMI enrolled (mean SD age, 61.1 11.6 years; 121 female patients 21.6%), LV thrombus was detected in 38 patients (13.7%) receiving rivaroxaban and 47 patients (16.6%) with DAPT alone (difference, −2.9%; 95% CI, −8.9% to 3.2%; P = .34). No difference was observed between the 2 groups regarding the largest diameter of LV thrombus or the incidence of major adverse cardiovascular events. The incidence of major bleeding events (Bleeding Academic Research Consortium BARC ≥type 2) was also comparable (4 1.5% with DAPT plus rivaroxaban vs 2 0.7% with DAPT alone; difference, 0.7%; 95% CI, −1.3% to 3.1%), whereas minor bleeding events (BARC type 1) occurred more frequently in the DAPT plus rivaroxaban group (45 16.4% vs 20 7.2%; difference, 9.3%; 95% CI, 3.6%-14.8%). Conclusions and Relevance In this multicenter randomized clinical trial among patients with anterior STEMI, the addition of low-dose rivaroxaban to DAPT did not demonstrate a statistically significant reduction in LV thrombus formation at 1 month but did increase minor bleeding. Given the limited power of the study, these findings should be interpreted with caution, as a modest effect cannot be excluded. Trial Registration ClinicalTrials.gov Identifier: NCT05077683