Rivaroxaban fails to take on covert brain infarcts
Use of rivaroxaban, with or without aspirin, falls short of reducing the number of incident covert infarcts compared with aspirin alone in patients with stable coronary and peripheral vascular disease, according to a study.
The current analysis included a subgroup of 1,445 participants with stable vascular disease from the COMPASS trial, which evaluated the effect of rivaroxaban with or without aspirin compared with aspirin monotherapy on stroke, myocardial infarction, and vascular death outcomes. All participants had completed baseline and follow-up magnetic resonance imaging (MRI) with a mean interval of 2.0 years. Whole-brain T1, T2 fluid-attenuated inversion recovery, T2 sequences were centrally interpreted by blinded, trained readers. Cognition and functional status were also assessed.
At baseline, 493 (34.1 percent) participants had infarcts. Incident covert infarcts occurred in 55 (3.8 percent) participants over the follow-up. In the overall trial, rivaroxaban plus aspirin vs aspirin monotherapy reduced the risk of ischaemic stroke by 49 percent (0.7 percent vs 1.4 percent; hazard ratio, 0.51, 95 percent confidence interval [CI], 0.38–0.68).
In the MRI substudy, the combination of rivaroxaban plus aspirin did not significantly differ with aspirin alone in terms of the incidence of covert infarcts (2.7 percent vs 3.5 percent; odds ratio [OR], 0.77, 95 percent CI, 0.37–1.60; p=0.48) and the composite of covert infarcts or ischaemic stroke (2.9 percent vs 5.3 percent; OR, 0.53, 95 percent CI, 0.27–1.03; p=0.061).
Overall, 6.6 percent of participants developed microbleeds and 65.7 percent had an increase in white matter hyperintensities volume, with no effect of treatment for either endpoint. Results for cognitive tests showed no material change.
In light of the findings, the researchers underscored that a sequential hierarchical analysis plan with a combined outcome of covert and clinical infarcts, followed by each component separately, might be optimal.