To the Editor Dr Carrero and colleagues1 evaluated the influence of chronic kidney disease (CKD) on the efficacy and safety of warfarin therapy in a population with atrial fibrillation and recent myocardial infarction. Previous studies have found that warfarin, when added to aspirin or dual antiplatelet therapy, is associated with increased risk of major bleeding.2,3 We thus find it surprising that, in this registry-based Swedish investigation, no excess bleeding risk was observed in warfarin users across stages of CKD. Accordingly, the characteristics of the study population deserve careful examination.
Vaduganathan M, Greene SJ. Influence of Chronic Kidney Disease on Warfarin Therapy for Atrial Fibrillation. JAMA. 2014;311(24):2541-2542. doi:10.1001/jama.2014.5576