Study of 6529 Afib pts on warfarin, 37.5% were also on aspirin. Adding aspirin to warfarin yielded significantly more bleeding (26 vs 20%), major bleeding (5.7 vs 3.3%), ER visits (13.3 vs 9.8%) but similar thrombosis rates (2.3 vs 2.7%) at 1 yr. https://t.co/m5XDBEN6jh