Warfarin plus aspirin tied to higher bleeding risk than monotherapy in AF patients

The combination of aspirin and warfarin therapy appears to increase the risk of bleeding, with little benefit in reducing stroke or cardiovascular events compared with warfarin alone in patients with atrial fibrillation (AF), reveals a study.

“Guidelines have differing recommendations for aspirin use in patients with an indication for anticoagulation,” the authors said.

This retrospective cohort study sought to assess the incidence of major bleeding and thromboembolic events in AF patients treated with warfarin alone (monotherapy group) or warfarin plus aspirin (combination therapy group). Patients were recruited from a pharmacist-run anticoagulation clinic and included if they had received anticoagulation between January 2013 and January 2014 over 5 years.

Of the participants, 142 received the combination therapy and 89 monotherapy. Among those in the combination group, 60 (42.3 percent) were taking aspirin for no apparent indication, 19 (13.4 percent) had stable coronary artery disease and diabetes, and 26 (18.3 percent) had diabetes alone.

More patients in the combination than in the monotherapy group experienced major bleeding (21 vs 7: 14.9 percent vs 7.9 percent; odds ratio [OR], 2.02, 95 percent confidence interval [CI], 0.78–5.91; p=0.17), as well as thromboembolic events (10 vs 4: 7 percent vs 4.5 percent; OR, 1.61, 95 percent CI, 0.44–7.24; p=0.57).

Of note, no significant difference in bleeding (p=0.85) or thromboembolic events (p=0.37) was observed between aspirin indications in the combination group.