Abstract 17126: Efficacy and Safety of Dabigatran Compared With Warfarin in Patients With Atrial Fibrillation and Normal Renal Function Over Time: Insights From the RE-LY Trial

Background: In patients with atrial fibrillation (AF) and normal renal function it has been reported that one oral factor-Xa inhibitor is associated with decreased efficacy compared to warfarin. In the RE-LY trial of patients with AF dabigatran, with approximately 80% renal elimination, was superior to warfarin for prevention of stroke and systemic embolism (SEE) with the 150 mg dose and non-inferior with the 110 mg dose and associated with significantly less major bleeding with the 110 mg dose. This is a post hoc analysis of the efficacy and safety of dabigatran vs. warfarin treatment in patients with normal renal function during the study. Methods: In the RE-LY trial among patients who received at least one dose of study medication, 17882 had creatinine measurements available at baseline, out of which 91% also had measurements after randomization. There were a total of 382 stroke/SEE, 280 ischemic strokes, and 1018 major bleed events during median follow-up of 1.8 years. The relations between outcomes, treatment, and renal function (Cockcroft-Gault estimated glomerular filtration rate (eGFR)) during follow-up were evaluated using Cox regression including treatment, eGFR as a continuous time dependent covariate, fitted using restricted cubic splines, and interaction. Hazard ratios (95% CI) comparing treatment effects were analyzed according to eGFR level. Results: In patients with normal renal function the relative risk of stroke/SEE was consistently lower in those treated with dabigatran as compared with warfarin. The patterns were similar for major bleeding with a trend of greater relative risk reduction with dabigatran as compared to warfarin at normal renal function. Conclusions: In patients with AF and normal renal function during treatment the efficacy of dabigatran compared to warfarin was consistent with the overall result of the RELY study. Both dabigatran doses were associated with lower risk of major bleeding in patients with normal renal function.