Rivaroxaban helps in preventing LV thrombus formation in MI patients: JACC study

Left ventricular thrombus (LVT) usually appears within 1 month after ST-segment elevation myocardial infarction (STEMI) with an incidence still ranging between 4-26% in the current primary PCI era. LVT usually complicates acute myocardial infarction and is associated with a higher incidence of poor outcomes. While the use of VKA antagonists has not been successful prophylactic strategy in this regard, a recent research has shown a useful role of low dose rivaroxaban in addition to DAPT to prevent LVT formation.

In the latest issue of JACC Cardiovascular Interventions, Zhang et al have shown that short-duration addition of low-dose rivaroxaban to DAPT could reduce LVT formation by as much as 92% in patients with anterior STEMI following primary percutaneous coronary intervention when compared to those taking DAPT alone.

For left ventricle thromboprophylaxis in high risk patients with AWMI, clinicians continue to face uncertainty in decision making. However, the advent of direct oral anticoagulants (DOACs), which attenuate fibrin formation by selective inhibition of factor Xa or thrombin, has renewed the interest in inhibition strategies that combine DAPT with an anticoagulant drug in this area.

The authors randomly assigned 279 patients with anterior STEMI who had undergone primary PCI to receive, in a 1:1 ratio, low-dose rivaroxaban (2.5 mg twice daily for 30 days) and DAPT or only DAPT.

The primary efficacy outcome was the LVT formation within 30 days. Net clinical adverse events were assessed at 30 days and 180 days, including all-cause mortality, LVT, systemic embolism, rehospitalization for cardiovascular events, and bleeding.

The addition of low-dose rivaroxaban to DAPT reduced LVT formation within 30 days compared with only DAPT (0.7% vs 8.6). Net clinical adverse events were lower within 30 days in the rivaroxaban group versus those in the only DAPT group and remained relatively low throughout the follow-up period.

There were no significant differences in bleeding events between the 2 groups in 30 days and 180 days.

Due to poor outcomes after left ventricular thrombosis, estimating the risk of thrombus formation and embolization as well as the utility of prophylactic treatment remains critical. The net clinical benefit was measured by the composite of NACEs in this trial. The composite, which included all-cause mortality, LVT, SE, rehospitalization for cardiovascular events, and bleeding, favored the addition of rivaroxaban to DAPT in patients with anterior STEMI in the short duration.

Further studies are required to elucidate the mechanisms by which rivaroxaban favorably influences LVT formation in patients with anterior STEMI who had undergone interventional treatments. The duration of anticoagulation also needs to be further determined. But nonetheless, this study has shown a way forward for one of the most perplexing clinical situations i.e. how to provide thromboprophylaxis for LVT.

Source: JACC Cardiovascular Interventions: DOI: 10.1016/j.jcin.2022.01.285