HELLERUP, Denmark—Renal disease increases the already elevated risk of stroke or systemic thromboembolism that accompanies nonvalvular atrial fibrillation (Afib), reported MedPage Today.
Among patients hospitalized with Afib, those with either non-end-stage or end-stage chronic kidney disease (CKD) had significantly higher rates of stroke or systemic embolism compared with patients free from renal disease (6.44 and 5.61 versus 3.61 per 100 person-years), according to Jonas Bjerring Olesen, MD, of Copenhagen University Hospital Gentofte in Hellerup, Denmark, and colleagues.
Warfarin therapy was associated with decreased risks in the overall cohort (HR 0.59, 95% CI 0.57 to 0.62) and among those with end-stage renal disease (ESRD) (HR 0.44, 95% CI 0.26 to 0.74), but the reduction did not reach statistical significance for those with non-end-stage chronic kidney disease (HR 0.84, 95% CI 0.69 to 1.01), the researchers reported in the Aug. 16 issue of the New England Journal of Medicine.
However, bleeding risks, which also were increased in patients with kidney disease, were magnified with the use of warfarin, aspirin, or both.
"The net clinical effect of warfarin treatment requires careful assessment in patients with chronic kidney disease, and the data do not provide clear guidance regarding indications for anticoagulant therapy in patients with both atrial fibrillation and chronic kidney disease," Olesen and colleagues wrote.
"Certainly, close monitoring of the international normalized ratio is required when warfarin is administered," they continued. "Ideally, the role of warfarin (or of other, newer anticoagulant agents) in patients with atrial fibrillation who have chronic kidney disease should be evaluated in a clinical trial."