Fibrosis-4 index can predict improved renal function in acute heart failure with preserved ejection fraction

Improved renal function (IRF) observed in acute heart failure (AHF) is associated with poor prognosis. Since IRF is linked to renal congestion resulting from inadequate decongestion, predicting IRF could enhance management strategies. The Fibrosis-4 (Fib-4) index, originally developed as a marker for liver fibrosis, correlates with hepatic congestion, which is associated with renal congestion, making it a potential predictor of IRF. This study aims to investigate whether the Fib-4 index can predict IRF in patients with AHF and preserved ejection fraction (AHFpEF).

We analyzed 389 patients hospitalized for AHF between April 2004 and March 2022 at Yamanashi University Hospital. All-cause mortality was monitored for 1 year. IRF was defined as a ≥ 20% increase in the estimated glomerular filtration rate (eGFR) compared to admission levels. Preserved ejection fraction was defined as an ejection fraction ≥ 40%.

IRF was observed in approximately 21% of patients with AHFpEF. Kaplan-Meier analysis showed that patients with IRF had higher mortality rates than those without IRF (p = 0.03, log-rank test). Multivariable analysis for IRF revealed that the eGFR, albumin level, and a Fib-4 index ≥ 3.24 (determined by receiver-operating characteristic curve) on admission were independent predictors of IRF in patients with AHFpEF.

IRF in patients with AHFpEF is associated with poor prognosis. A higher Fib-4 index at admission in AHFpEF can serve as a predictor of IRF.