Renal function in heart failure: a disparity between estimating function and predicting mortality risk.

Aims To compare the predictive value of estimated renal function calculated by the Chronic Kidney Disease Epidemiology Collaboration (eGFRCKD-EPI), four-variable Modification of Diet in Renal Disease (eGFRMDRD-4), and Cockcroft–Gault [estimated creatinine clearance (eCcr)] equation in terms of all-cause mortality in heart failure. Renal function is an important prognostic factor in heart failure. Established methods of estimating renal function are known to under-/overestimate true function in certain settings. Methods and results A total of 800 systolic heart failure outpatients (mean age 57 ± 11.5 years, 82% male) were studied over a median follow-up of 121 (Q1–Q3: 110–130) months. The highest systematic difference was seen between eCcr and eGFRMDRD-4 [+12.33 points (mean), 95% limits of agreement –22.35 to 47.01; generalized kappa = 0.36]. eGFRMDRD-4 and eGFRCKD-EPI were the most similar [–4.16 points (mean), 95% limits of agreement –11.56 to 3.25; generalized kappa = 0.74]. Up to 35.4% of patients were reclassified into different estimated glomerular filtration rate (eGFR) categories when comparing eGFRCKD-EPI with eCcr and eGFRMDRD-4. eGFRCKD-EPI performed marginally better in terms of predicting all-cause mortality than eGFRMDRD-4, as univariate areas under the time-dependent receiver operating characteristic curves (AUC), marginal and partial proportions of explained variation (PEV), net reclassification improvement (NRI), and the integrated discrimination improvement (IDI) for 5 years of follow-up were significantly higher for eGFRCKD-EPI than for eGFRMDRD-4. Conclusion In this cohort of heart failure patients, eGFRCKD-EPI was marginally better in predicting all-cause mortality than eGFRMDRD-4. Estimated function differed widely between equations and is likely to have an effect on therapy choice. [ABSTRACT FROM PUBLISHER]