Safety and Efficacy of Adjusted Dose of Rivaroxaban in Japanese Patients With Non-Valvular Atrial Fibrillation

Background: In the Japanese Rivaroxaban Once-daily oral direct factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation (J-ROCKET AF) study, rivaroxaban 15mg once daily was given to patients with creatinine clearance (CrCl) ≥50ml/min (preserved renal function), and was reduced to 10mg once daily in patients with CrCl 30–49ml/min (moderate renal impairment). The aim of this subanalysis was to assess the safety and efficacy of the adjusted dose of rivaroxaban compared with warfarin in a cohort with moderate renal impairment. Methods and Results: Compared with patients with preserved renal function, those with moderate renal impairment (22.2% of all randomized patients) had higher rates of bleeding and stroke events irrespective of study treatment. Among those with moderate renal impairment, the principal safety endpoint occurred at 27.76%/year with rivaroxaban vs. 22.85%/year with warfarin (hazard ratio [HR], 1.22; 95% confidence interval [CI]: 0.78–1.91) and the rate of the primary efficacy endpoint was 2.77%/year vs. 3.34%/year (HR, 0.82; 95% CI: 0.25–2.69), respectively. There were no significant interactions between renal function and study treatment in the principal safety and the primary efficacy endpoints (P=0.628, 0.279 for both interactions, respectively). Conclusions: The safety and efficacy of rivaroxaban vs. warfarin were consistent in patients with moderate renal impairment and preserved renal function.  (Circ J 2013; 77: 632–638)