The role of rivaroxaban in atrial fibrillation and acute coronary syndromes.

Rivaroxaban, a direct factor Xa inhibitor, is a novel oral anticoagulant approved for stroke prevention in patients with nonvalvular atrial fibrillation and also approved in Europe (but not in the United States) to prevent recurrent ischemic events in patients with recent acute coronary syndromes. Advantages of rivaroxaban over oral anticoagulants such as warfarin are the lack of need for ongoing monitoring, a fixed-dose regimen, and fewer drug and food interactions. Drawbacks include a lack of an antidote and the absence of a widely available method to reliably monitor the anticoagulant effect. In patients at risk of stroke due to atrial fibrillation, rivaroxaban was noninferior compared to warfarin in preventing stroke/systemic embolism in the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF) trial and was associated with a similar risk of major bleeding; the incidence of intracranial hemorrhage was 33% lower with rivaroxaban. Concerns raised about the trial were the adequacy of warfarin management and the increase in event rate at the end of the trial. The drug acquisition cost of rivaroxaban is higher than that of warfarin although decision-analytic models suggest that it is cost effective in atrial fibrillation. In patients with recent acute coronary syndrome, low-dose rivaroxaban reduced mortality and the composite end point of death from cardiovascular causes, myocardial infarction and stroke, but this was accompanied by an increased risk of intracranial hemorrhage and major bleeding in the Rivaroxaban in Combination With Aspirin Alone or With Aspirin and a Thienopyridine in Patients With Acute Coronary Syndromes-Thrombolysis in Myocardial Infarction (ATLAS ACS 2-TIMI) 51 trial. Thus, rivaroxaban appears to be a valuable addition to the therapeutic armamentarium in atrial fibrillation although caution should be exercised, given the limited experience in combination with novel oral antiplatelet agents. The role of rivaroxaban as part of a modern regimen in acute coronary syndrome continues to be evaluated.