Thrombocytopenia Portends Excess Bleeding Risk from Anticoagulation for Atrial Fibrillation

The effect of thrombocytopenia on bleeding risk among patients who are receiving anticoagulation for atrial fibrillation (AF) is unknown. In this retrospective, single-center U.S. study of patients with AF, researchers compared bleeding outcomes among 274 patients with thrombocytopenia (platelet count, <100,000 cells/μL) and 796 patients without thrombocytopenia (platelet count, >150,000 cells/μL) who were matched by age, sex, CHA2DS2-VASc score, and anticoagulant; other characteristics differed widely. About half of patients received warfarin, 40% received apixaban, and about 75% also were taking antiplatelet drugs (mostly aspirin).

More than half of all bleeds among patients with thrombocytopenia were major events, compared with only one t…