Anterior ST-Segment Elevation Myocardial Infarction (STEMI) is associated with increased risk of left ventricular (LV) thrombus. The role of adding oral anticoagulation to dual antiplatelet therapy (DAPT) for prevention of LV thrombus remains uncertain. This multicenter, open-label, blinded–end point randomized clinical trial assessed whether low-dose rivaroxaban added to DAPT reduces LV thrombus formation at 1 month. The study was published in the JAMA Cardiology.

Conducted across 29 centers in France and nested within the FRENCHIE registry, the trial enrolled 560 patients with anterior STEMI between October 2021 and January 2023. Patients were randomized to DAPT plus rivaroxaban 2.5 mg twice daily for 4 weeks (n = 283) or DAPT alone (aspirin ≤100 mg daily plus clopidogrel 75 mg daily or ticagrelor 90 mg twice daily; n=277), initiated after percutaneous coronary intervention or angiography. The primary endpoint was LV thrombus detected by contrast-enhanced cardiac magnetic resonance imaging at 1 month.

LV thrombus occurred in 13.7% with rivaroxaban and 16.6% with DAPT alone (difference −2.9%; 95% CI −8.9% to 3.2%; P=0.34). No differences were observed in thrombus size or major adverse cardiovascular events. Major bleeding (Bleeding Academic Research Consortium [BARC] ≥type 2) occurred in 1.5% with rivaroxaban and 0.7% with DAPT alone (difference, 0.7%; 95% CI, −1.3% to 3.1%). Minor bleeding (BARC type 1) occurred more frequently with rivaroxaban (16.4% vs 7.2%; difference, 9.3%; 95% CI, 3.6%-14.8%).

Addition of low-dose rivaroxaban did not significantly reduce LV thrombus at 1 month. Minor bleeding was increased. Given the limited statistical power of the trial, a modest treatment effect cannot be excluded.