Direct oral anticoagulants versus warfarin in patients with non-valvular atrial fibrillation and CKD G3–G5D

Background: The use of direct oral anticoagulants (DOAC) in patients with non-valvular atrial fibrillation (NVAF) and advanced chronic kidney disease (CKD) including dialysis is growing. Several studies have shown favorable results of DOAC compared with warfarin regarding bleeding risk but no difference in stroke protection. However, these studies had poor time in therapeutic range (TTR), in the warfarin comparison group. Methods: This was a Swedish national cohort study investigating the risk of ischemic stroke and major bleeding on DOAC compared with warfarin in patients with NVAF, glomerular filtration rate category 3-5D (G3-G5D), kidney transplant recipients excluded, between 2009 and 2018. Data extracted from high-quality national healthcare registries including the Swedish Renal Registry, AuriculA (the Swedish national quality register for AF and anticoagulation) and The Stroke Register. Results: At enrolment, of 2453 patients 59% were treated with warfarin (mean TTR 67%) and 41% with DOAC. Overall, 693 (28.3%) had G3, 1113 (45.4%) G4, 222 (9.1%) G5 and 425 (17.3%) G5D. DOAC compared with warfarin showed lower hazard of major bleeding hazard ratio 0.71 (95% confidence interval 0.53-0.96) but no difference in ischemic stroke risk. Mortality was increased during DOAC treatment 1.24 (1.01-1.53), presumably not a causal association since fewer fatal bleedings occurred on DOAC. Conclusions: DOAC treatment, compared with warfarin, is associated with almost 30% lower risk of bleeding in patients with NVAF and CKD G3-G5D. The stroke risk is comparable between the treatments. This is the first study comparing DOAC and well-managed warfarin (TTR 67%) in advanced CKD. Ongoing and planned randomized controlled trials need to confirm the possible benefit of DOAC.