Discharge FGF23 level predicts one year outcome in patients admitted with acute heart failure

Patients with acute heart failure (AHF) show high levels of fibroblast growth factor-23 (FGF23) on admission. We examined if plasma FGF23 changes during an episode of AHF, and if FGF23 holds prognostic significance in this setting.

Consecutive AHF patients were enrolled. Blood samples were collected on admission and at discharge. Patients were then followed for all-cause death or HF hospitalization.

Patients (n = 125; median age 76 years [interquartile interval 71-83], 63% men, left ventricular ejection fraction 35% [25%-56%]) had median admission FGF23 70 ng/L (47-100), N-terminal pro-B-type natriuretic peptide (NT-proBNP) 5844 ng/L (2,503-10,468), high-sensitivity troponin T (hs-TnT) 40 ng/L (25-72), and soluble suppression of tumorigenesis-2 (sST2) 26 ng/mL (17-37). While other biomarkers decreased, FGF23 increased by 15% from admission to discharge (p = 0.033), with a significant correlation with percent changes in estimated glomerular filtration rate (rho = 0.306, p = 0.001). Over a 12-month follow-up, 64 patients (51%) experienced the endpoint. They were more often men, older, with higher systolic pulmonary artery pressure (sPAP), higher NT-proBNP, hs-TnT and discharge FGF23. The best FGF23 cut-off at discharge from receiver operating characteristics analysis was 78 ng/L. Both discharge FGF23 and the 78 ng/L cut-off independently predicted outcome in models including gender, sPAP, age, and 1) admission NT-proBNP, 2) discharge NT-proBNP, 3) admission NT-proBNP and hs-TnT, 4) discharge NT-proBNP and hs-TnT. The 78 ng/L cut-off also refined risk reclassification.

During an AHF episode, FGF23 increases from admission to discharge, and patients with higher discharge FGF23 have a higher risk of worse outcome.