Clinical Implications of Estimating Glomerular Filtration Rate with Different Equations in Heart Failure Patients with Preserved Ejection Fraction.

Introduction: The prognostic values of estimated glomerular filtration rate (eGFR) calculated by different formulas have not been adequately compared in patients with heart failure with preserved ejection fraction (HFpEF).

Aim: We compared the predictive values of serum creatinine-based eGFRs calculated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2009 equation, Modification of Diet in Renal Disease Study (MDRD) formula, and full-age-spectrum creatinine (FAS Cr) equation in 1751 HFpEF patients.

Methods: The area under the receiver-operating characteristic curve (AUC), integrated discrimination improvement (IDI) and net reclassification improvement (NRI) were employed.

Results: eGFR values were lowest calculated with FAS Cr equation (p < 0.001). When patients were classified into 4 subgroups (eGFR ≥ 90, 89-60, 59-30, and  < 30 ml/min/1.73 m²) or only 2 subgroups (≥ 60 or  < 60 ml/min/1.73 m²), the 3 formulas correlated significantly, with the best correlation found between the MDRD and CKD-EPI formulas (kappa = 0.871 and 0.963, respectively). The 3 formulas conveyed independent prognostic information. After adjusting for potential cofounders, risk prediction for all-cause mortality was more accurate (p = 0.001) using the CKD-EPI equation than MDRD formula as assessed by AUC. Compared with MDRD formula, CKD-EPI equation exhibited superior predictive ability assessed by IDI and NRI of 0.32% (p < 0.001)/10.4% (p = 0.010) for primary endpoint and 0.37% (p = 0.010)/10.8% (p = 0.010) for HF hospitalization. The risk prediction for deterioration of renal function was more accurate (p ≤ 0.040) using the CKD-EPI equation than FAS Cr equation as assessed by AUC, IDI, and NRI.

Conclusion: The CKD-EPI formula might be the preferred creatinine-based equation in clinical risk stratification in HFpEF patients.