comparative clinical outcomes between direct oral anticoagulants and warfarin among elderly patients with non-valvular atrial fibrillation in the cms medicare population

Atrial fibrillation (af) prevalence increases with age; > 80% of us adults with af are aged ≥ 65 years. compare the risk of stroke/systemic embolism (se), major bleeding (mb), net clinical outcome (nco), and major adverse cardiac events (mace) among elderly non-valvular af (nvaf) medicare patients prescribed direct oral anticoagulants (doacs) vs warfarin. nvaf patients aged ≥ 65 years who initiated doacs (apixaban, dabigatran, and rivaroxaban) or warfarin were selected from 01jan2013-31dec2015 in cms medicare data. propensity score matching was used to balance doac and warfarin cohorts. cox proportional hazards models estimated the risk of stroke/se, mb, nco, and mace. 37,525 apixaban–warfarin, 18,131 dabigatran–warfarin, and 55,359 rivaroxaban–warfarin pairs were included. compared to warfarin, apixaban (hr: 0.69; 95% ci 0.59–0.81) and rivaroxaban (hr: 0.82; 95% ci 0.73–0.91) had lower risk of stroke/se, and dabigatran (hr: 0.88; 95% ci 0.72–1.07) had similar risk of stroke/se. apixaban (mb: hr: 0.61; 95% ci 0.57–0.67; nco: hr: 0.64; 95% ci 0.60–0.69) and dabigatran (mb: hr: 0.79; 95% ci 0.71–0.89; nco: hr: 0.84; 95% ci 0.76–0.93) had lower risk of mb and nco, and rivaroxaban had higher risk of mb (hr: 1.08; 95% ci 1.02–1.14) and similar risk of nco (hr: 1.04; 95% ci 0.99–1.09). compared to warfarin, apixaban had a lower risk for stroke/se, mb, and nco; dabigatran had a lower risk of mb and nco; and rivaroxaban had a lower risk of stroke/se but higher risk of mb. all doacs had lower risk of mace compared to warfarin.