Prophylactic Rivaroxaban Therapy for Left Ventricular Thrombus after ST-Segment Elevation Acute Coronary Syndrome

The incidence of left ventricular thrombosis (LVT) after anterior ST-segment elevation myocardial infarction (STEMI) ranges from 4% to 26%. This is associated with bad long-term evolution.

El ticagrelor muestra beneficios en la función microvascular coronaria luego de un IAMSEST

In the past, triple-scheme therapy (vitamin K antagonist plus dual antiplatelet therapy) was recommended to prevent LVT, despite the lack of high-quality scientific evidence and an increase in the risk for major bleeding.

The development of direct oral anticoagulants (DOACs) has renewed the interest on this area. One of the most widely used, rivaroxaban, has shown positive results in thromboprophylaxis for atrial fibrillation.

The aim of this randomized, controlled, superiority study was to evaluate the effectiveness of rivaroxaban plus DAPT regarding LVT formation in patients with prior STEMI.

The primary endpoint (PEP) was LVT formation at 30 days. The secondary endpoint (SEP) was a composite of overall mortality, LVT, systemic embolism, re-hospitalization for cardiovascular events, or bleeding. There was also a safety endpoint, which was a composite of clinically-relevant major and minor bleeding at 30 days.

The study enrolled 279 patients: 139 randomized to the rivaroxaban arm (2.5 mg BID) plus DAPT, and 140 to the DAPT only arm.

Mean age was 58 years old, most patients were male, and half of them had dyslipidemia and smoked. In most patients, Killip-Kimball class was 1, ejection fraction was 55%, and 40% had multivessel lesion. The time between symptom-onset-to-balloon was within 12 hours in 85% of cases. DAPT was included ticagrelor in 64% of cases; all other patients received clopidogrel.

The PEP showed a lower incidence of LVT in the rivaroxaban arm vs. the DAPT only arm, 0.7% vs. 8.6% respectively, (hazard ratio [HR]: 0.08; 95% confidence interval [CI]: 0.01 to 0.62; p = 0.015). In terms of the SEP, patients in the rivaroxaban arm experienced fewer clinical adverse events (HR: 0.37; 95% CI: 0.17 to 0.80; p = 0.011) at the expense of fewer systemic embolizations, with no difference in the rest of the events.

Conclusion

Adding low doses of rivaroxaban to DAPT prevents LVT formation in patients with prior STEMI who underwent a coronary intervention. Further studies are needed to evaluate its long-term efficacy and safety.