Prognostic implications of a four-group classification based on estimated plasma volume status and creatinine in acute heart failure.

Abstract

We evaluated the prognostic value of a four-group classification combining estimated plasma volume status (ePVS) and serum creatinine (Cre) in patients hospitalized for acute decompensated heart failure (ADHF). We analyzed 914 patients from the SAKURA HF Registry-2 enrolled between September 2018 and December 2023. At discharge, patients were stratified into four groups using ePVS (cutoff, 5.5 mL/g) and Cre (cutoff, 1.1 mg/dL): low-ePVS/low-Cre (n = 285), high-ePVS/low-Cre (n = 136), low-ePVS/high-Cre (n = 263), and high-ePVS/high-Cre (n = 230). The primary endpoint was a composite of all-cause mortality or heart failure rehospitalization. Multivariable Cox models were adjusted for clinical, laboratory, echocardiographic, and discharge-medication covariates. Median age was 74 years and 68% were men. Over a median follow-up of 368 days (interquartile range [IQR], 89-548), 349 patients (38.2%) experienced the primary endpoint, with significant differences among groups (log-rank p < 0.001). In multivariable models, compared with low-ePVS/low-Cre, risk was higher in high-ePVS/low-Cre (hazard ratio [HR] 2.38, 95% confidence interval [CI] 1.31-4.30; p = 0.004) and high-ePVS/high-Cre (HR 1.98, 95% CI 1.12-3.48; p = 0.018), but not in low-ePVS/high-Cre (HR 1.62, 95% CI 0.94-2.79; p = 0.08). A discharge-based ePVS-Cre classification provided clinically relevant risk stratification after ADHF. Elevated ePVS despite non-elevated serum creatinine independently predicted adverse outcomes. When ePVS was low, the excess risk associated with elevated creatinine was attenuated after adjustment, whereas concomitant elevation of ePVS and creatinine remained a high-risk category. This simple bedside framework may support discharge risk assessment.