In patients with an embolic stroke of undetermined source, rivaroxaban and aspirin provide similar benefit for preventing recurrent stroke, according to a study published in the New England Journal of Medicine. Although rivaroxaban is nonsuperior to aspirin for the prevention of recurrent stroke, it appears to increase the risk for bleeding in these patients.
Patients who experienced a recent ischemic stroke of undetermined origin were randomly assigned to either 15 mg/day rivaroxaban (n=3609) or 100 mg/day aspirin (n=3604) for recurrent stroke prevention. Investigators compared the 2 groups in terms of efficacy (ie, ischemic or hemorrhagic stroke recurrence or systemic embolism) and safety (ie, major bleeding) outcomes. A composite consisting of cardiovascular-related mortality, stroke recurrence, systemic embolism, myocardial infarction, all-cause mortality, disabling stroke, or fatal stroke comprised the secondary efficacy outcome.
During a median follow-up of 11 months, a total of 172 and 160 patients in the rivaroxaban and aspirin groups, respectively, experienced a recurrent stroke of any type or a systemic embolism (annualized rates, 5.1% and 4.8%, respectively; hazard ratio [HR] 1.07; 95% CI, 0.87-1.33; P =.52). There was no difference between the rivaroxaban and aspirin groups with regard to recurrence of ischemic stroke (annualized rates, 4.7% and 4.7%, respectively; HR 1.01; 95% CI, 0.81-1.26). A significantly greater number of patients in the rivaroxaban group experienced a major bleeding event compared with patients in the aspirin group (annualized rates, 1.8% vs 0.7%, respectively; HR 2.72; 95% CI, 1.68-4.39; P <.001).
Early termination because of lack of benefit as well as increased bleeding event rates in the rivaroxaban group limit the findings to short-term outcomes only.
According to the investigators, the “heterogeneous underlying sources of the embolic strokes (arterial, cardiogenic, or paradoxic) with variation in the composition of emboli may have resulted” in a study population that may not have a rivaroxaban response.
Hart RG, Sharma M, Mundl H, et al; for the NAVIGATE ESUS Investigators. Rivaroxaban for stroke prevention after embolic stroke of undetermined source. N Engl J Med. 2018;378:2191-2201.