Clinical question: Is rivaroxaban alone or in combination with aspirin more effective than is aspirin alone in preventing cardiovascular events in patients with stable atherosclerotic disease?
Background: Previous studies have shown that, among patients with stable atherosclerosis, anticoagulation with a vitamin-K antagonist (VKA) plus aspirin is superior to aspirin alone for secondary prevention but has increased rates of major bleeding.
Study design: Randomized controlled trial.
Setting: 602 sites in 33 countries.
Synopsis: In 27,395 patients with stable atherosclerotic disease, the addition of 2.5 mg rivaroxaban twice daily to aspirin therapy reduced the rates of cardiovascular death, stroke, or nonfatal MI, at the cost of increased major bleeding rates. The authors found a 1.3% absolute risk reduction in recurrent cardiovascular events, but a 1.2% absolute increase in major bleeding rates, although intracranial and fatal bleeding rates were similar between the two groups. The trial was stopped early for efficacy, which may overestimate the treatment effect. In addition, much of the benefit in the rivaroxaban-plus-aspirin group was driven by lower rates of ischemic stroke. Rates of myocardial infarction were not significantly different between the groups. The addition of rivaroxaban to aspirin for secondary prevention should be individualized and considered in patients at high risk for ischemic stroke with low bleeding risk.
Bottom line: Rivaroxaban plus aspirin lowers ischemic event rates in stable atherosclerosis compared to aspirin but increases major bleeding rates. Cost efficacy is uncertain.
Citation: Eikelboom JW et al. Rivaroxaban with or without aspirin in stable cardiovascular disease. N Engl J Med. 2017 Oct 5..
Dr. Theobald is a hospitalist at the University of Colorado School of Medicine.