Low-dose rivaroxaban plus aspirin in patients with polypharmacy and multimorbidity: an analysis from the COMPASS trial

AIMS: To analyse whether the benefits and risks of rivaroxaban plus aspirin vary in patients with comorbidities and receiving multiple drugs. In patients with coronary or peripheral artery disease, adding low-dose rivaroxaban to aspirin reduces cardiovascular events and mortality. Polypharmacy and multimorbidity are frequent in such patients. METHODS AND RESULTS: We describe ischaemic events (cardiovascular death, stroke, or myocardial infarction) and major bleeding in participants from the randomized, double-blind COMPASS study by number of cardiovascular medications and concomitant medical conditions. We compared event rates and hazard ratios (HRs) for rivaroxaban plus aspirin vs. aspirin alone by the number of medications and concomitant conditions, and tested for interaction between polypharmacy or multimorbidity and the antithrombotic regimen. The risk of ischaemic events was higher in patients with more concomitant drugs (HR 1.7, 95% confidence interval 1.5-2.1 for >4 vs. 0-2) and with more comorbidities (HR 2.3, 1.8-2.1 for >3 vs. 0-1). Multimorbidity, but not polypharmacy, was associated with a higher risk of major bleeding. The relative efficacy, safety, and net clinical benefit of rivaroxaban were not affected by the number of drugs or comorbidities. Patients taking more concomitant medications derived the largest absolute reduction in the net clinical outcome with added rivaroxaban (1.1% vs. 0.4% reduction with >4 vs. 0-2 cardiovascular drugs, number needed to treat 91 vs. 250). CONCLUSION: Adding low-dose rivaroxaban to aspirin resulted in benefits irrespective of the number of concomitant drugs or comorbidities. Multiple comorbidities and/or polypharmacy should not dissuade the addition of rivaroxaban to aspirin in otherwise eligible patients.