RESUMO
Background: The use of rivaroxaban in patients with atrial fibrillation (AF) and chronic kidney disease (CKD) poses the risk of over- or underdosing. We aimed to compare rivaroxaban and warfarin in AF patients with moderate and severe renal impairment. Methods: This retrospective study was conducted between 2015 and 2016 to compare the use of warfarin (n = 164) and rivaroxaban (n = 149) in patients with AF and moderate or severe CKD. The study outcomes were survival, stroke, and major bleeding events. The median follow-up was 50 months (interquartile range: 23-60). Results: Thirty-six patients had major bleeding: 24 with rivaroxaban and 12 with warfarin (P = 0.01). The rivaroxaban group had major bleeding in 3 patients with moderate CKD, 4 with severe CKD, and 17 on dialysis. Multivariable analysis of factors affecting major bleeding revealed that warfarin use lowered the risk of bleeding (hazard ratio: 0.34; P = 0.004). Stroke occurred in 14 patients: 6 in the rivaroxaban group and 8 in the warfarin group (P = 0.44). Survival at 1, 3, and 5 years was 89%, 77%, and 71% with warfarin and 99%, 94%, and 88% with rivaroxaban, respectively (P < 0.001). Multivariable analysis showed higher mortality in patients with lower creatinine clearance and those on warfarin. Conclusions: The safety of warfarin could be better than rivaroxaban in patients with CKD with fewer bleeding complications but similar stroke rates. Further studies on rivaroxaban dosing in patients on dialysis are required.