Clinical question: Is there a difference between aspirin and warfarin in preventing thromboembolic complications and risk of bleeding in patients with chronic kidney disease (CKD) and nonvalvular atrial fibrillation (NVAF)?
Background: Data are lacking on risks and benefits of aspirin and warfarin in CKD, as this group of patients largely has been excluded from anticoagulation therapy trials for NVAF. This study examined the risks and benefits of aspirin and warfarin in patients with CKD with NVAF.
Study design: Retrospective, observational cohort study.
Setting: Danish National Registries.
Synopsis: Of 132,372 patients with NVAF, 2.7% had CKD and 0.7% had end-stage renal disease (ESRD). Compared to patients with no CKD, there was increased risk of stroke or systemic thromboembolism in patients with ESRD (HR, 1.83; 95% CI, 1.57-2.14) and with non-end-stage CKD (HR 1.49; 95% CI 1.38-1.59).
In patients with CKD, warfarin significantly reduced stroke risk (HR, 0.76; 95% CI, 0.64-0.91) and significantly increased bleeding risk (HR, 1.33; 95% CI, 1.16-1.53); aspirin significantly increased bleeding risk (HR, 1.17; 95% CI, 1.02-1.34), with no reduction in stroke risk.
Bottom line: CKD was associated with an increased risk of stroke among NVAF patients. While both aspirin and warfarin were associated with increased risk of bleeding, there was a reduction in the risk of stroke with warfarin, but not with aspirin.
Citation: Olesen JB, Lip GY, Kamper AL, et al. Stroke and bleeding in atrial fibrillation with chronic kidney disease. N Engl J Med. 2012;367(7):625-635.