Impact of 2021 Creatinine-Based Estimated Glomerular Filtration Rate Equation for Patients With Heart Failure: Classification of Stage of Kidney Disease and Association With Clinical Outcomes

Abstract

Estimated glomerular filtration rate (eGFR) equations were updated in 2021. The impact of these changes in eGFR in relation to prognosis for patients with heart failure (HF) are uncertain. Patients hospitalised with HF in the Northern Region of New Zealand during 2013–2014 were identified from administrative data, and integration of blood tests (including creatinine), cause-specific rehospitalisations, and mortality was undertaken. Creatinine at HF hospitalisation discharge was identified, and eGFR calculated using 2009 and 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. Four-year outcomes (death and death/HF hospitalisation) were assessed using multivariable Cox proportional hazards models with covariates of age, sex, ethnicity, deprivation index, diabetes, previous HF admission, ischaemic aetiology, and one of: log(creatinine), 2009 eGFR, or 2021 eGFR. The cohort included 6,531 patients: 46% were female; by ethnicity 16% Māori, 13% Pacific, 63% European; 40% had previous HF hospitalisation and 41% ischaemic aetiology. A total of 1,114 patients (21%) were classified as having one stage less severe CKD using the 2021 eGFR calculation compared with 2009 (Table); 145 patients with eGFR <30 were upstaged to eGFR ≥30 (14% of total eGFR <30). During follow-up, 3,683 (56%) patients died and 4,874 (75%) either died or had HF hospitalisation. In multivariable models, log(creatinine) was an independent predictor of death (HR 1.54; 95% CI 1.44–1.65) and death/HF hospitalisation (HR 1.28; 95% CI 1.21–1.36). In a real-world HF cohort, the 2021 eGFR equation classified more patients as having less severe CKD stages compared with 2009. Both equations had similar statistical significance for mortality and death/HF hospitalisation; 14% with eGFR <30 were reclassified to eGFR ≥30, which is an important threshold for HF therapeutics.TableCKD StageCKD EPI 2009CKD EPI 2021Net changeGlfeGRF ≥90)578873295G2 (eGRF ≥60 to <90)2261233574G3a (eGRF ≥45 to <60)14161329–87G3b (eGRF ≥30 to <45)12721135–137G4 (eGRF ≥15 to <30)738616–122G5 (eGRF <15)266243–23 Open table in a new tab