AIM: To compare the performance of the re-expressed Modification of Diet in Renal Disease equation vs the new Chronic Kidney Disease Epidemiology Collaboration equation in patients with non-valvular atrial fibrillation.METHODS: We studied 911 consecutive patients with non-valvular atrial fibrillation on vitamin-K antagonist. The performance of the re-expressed Modification of Diet in Renal Disease equation vs the new Chronic Kidney Disease Epidemiology Collaboration equation in patients with non-valvular atrial fibrillation with respect to either a composite endpoint of major bleeding, thromboembolic events and all-cause mortality or each individual component of the composite endpoint was assessed using continuous and categorical ≥ 60, 59-30, and < 30 m L/min per 1.73 m2 estimated glomerular filtration rate.RESULTS: During 10 ± 3 mo, the composite endpoint occurred in 98(10.8%) patients: 30 patients developed major bleeding, 18 had thromboembolic events, and 60 died. The new equation provided lower prevalence of renal dysfunction < 60 m L/min per 1.73 m2(32.9%),compared with the re-expressed equation(34.1%). Estimated glomerular filtration rate from both equations was independent predictor of composite endpoint(HR = 0.98 and 0.97 for the re-expressed and the new equation, respectively; P < 0.0001) and all-cause mortality(HR = 0.98 for both equations, P < 0.01). Strong association with thromboembolic events was observed only when estimated glomerular filtration rate was < 30 m L/min per 1.73 m2: HR is 5.1 for the re-expressed equation, and HR = 5.0 for the new equation. No significant association with major bleeding was observed for both equations.CONCLUSION: The new equation reduced the prevalence of renal dysfunction. Both equations performed similarly in predicting major adverse outcomes. AIM: To compare the performance of the re-expressed Modification of Diet in Renal Disease equation vs the new Chronic Kidney Disease Epidemiology Collaboration equation in patients with non-valvular atrial fibrillation. METHODS: We studied 911 consecutive patients with non-valvular atrial fibrillation on vitamin-K antagonist. The performance of the re-expressed Modification of Diet in Renal Disease equation vs the new Chronic Kidney Disease Epidemiology Collaboration equation in patients with non-valvular atrial fibrillation with respect to either a composite endpoint of major bleeding, thromboembolic events and all-cause mortality or each individual component of the composite endpoint was assessed using continuous and categorical ≥ 60, 59-30, and <30 m L / min per 1.73 m2 estimated glomerular filtration rate .RESULTS: During 10 ± 3 mo, the composite thirteen occurred major bleeding, 18 had thrombboembolic events, and 60 died. The new equatio Compared with the re-expressed equation (34.1%). Estimated glomerular filtration rate from both equations was independent predictor of composite endpoint (HR = 0.98 and 0.97 for the re-expressed and the new equation, respectively; P <0.0001) and all-cause mortality (HR = 0.98 for both equations, P <0.01). Strong association with thromboembolic events was observed only when estimated glomerular filtration rate was <30 m L / min per 1.73 m2: HR is 5.1 for the re-expressed equation, and HR = 5.0 for the new equation. No significant association with major bleeding was observed for both equations. CONCLUSION: The new equation reduced the prevalence of renal dysfunction. Both Methods are similarly predictive major adverse outcomes.