Secondary stroke prophylaxis in atrial fibrillation patients with chronic kidney disease: a nationwide cohort study.

Abstract

Oral anticoagulation (OAC) therapy as secondary stroke prophylaxis in atrial fibrillation (AF) patients with chronic kidney disease (CKD) remains unexplored and poses a clinical treatment dilemma. We assessed the long-term risk of thromboembolic events according to post-stroke OAC therapy in AF patients with CKD after their first ischaemic stroke. We identified Danish AF patients with CKD who presented with first-time ischaemic stroke from 2005 to 2014. Chronic kidney disease was defined as a diagnosis code for CKD before baseline, defined as 100 days after stroke discharge. Post-stroke antithrombotic therapy (OAC therapy and antiplatelet therapy) was identified from prescription claims from discharge to baseline. Cumulative incidences and adjusted hazard ratios (HRs) of thromboembolic events according to post-stroke OAC therapy were examined. Of 1252 AF patients with CKD presenting with ischaemic stroke, 631 (50.4%) patients were on OAC therapy and 621 (49.6%) were on antiplatelet therapy alone at baseline [median age 76 (interquartile range, IQR 71-83) and 80 (IQR 72-86), respectively]. The median follow-up period was 1.9 years (IQR 0.8-3.6). Cumulative incidence rates of thromboembolic events and bleeding showed no significant difference between those on OAC therapy and antiplatelet therapy. The results from the multivariable analysis revealed similar results: thromboembolic risk was not modified by OAC treatment [adjusted HR 0.89, 95% confidence interval (CI) 0.73-1.09] nor was the risk of bleeding (adjusted HR 0.88, 95% CI 0.67-1.17). Oral anticoagulation in patients with CKD and prior stroke was not associated with a reduced risk of recurrent thromboembolic events compared with antiplatelet therapy.