Association of nutritional status assessed by the controlling nutritional status score with clinical outcomes in adults with heart failure with preserved ejection fraction

Objective To investigate the association of the controlling nutritional status (CONUT) score with the 1-year risk of readmission and all-cause mortality in patients with heart failure with preserved ejection fraction (HFpEF) after discharge, and to compare its prognostic performance with the geriatric nutritional risk index (GNRI) and the prognostic nutritional index (PNI). Methods This multicenter ambispective observational cohort study enrolled adults hospitalized with HFpEF. Patients were stratified according to admission CONUT scores into normal nutrition (0–1 points, n = 85), mild risk (2–4 points, n = 113), moderate risk (5–8 points, n = 79), and severe risk (9–12 points, n = 62) groups. The primary endpoints were 1-year readmission and all-cause mortality; cardiogenic shock was evaluated as an exploratory endpoint. Statistical analyses included Kaplan–Meier survival curves, Cox proportional hazards regression models, and receiver operating characteristic (ROC) curves. Results A total of 339 patients with HFpEF were analyzed, with a 1-year follow-up completion rate of 96.03%. Higher CONUT risk grades were associated with higher crude rates of 1-year readmission (17.65 to 29.03%, p = 0.024) and all-cause mortality (3.53 to 29.03%, p < 0.001). Cardiogenic shock occurred in 12 patients (3.54%); its incidence differed across CONUT groups by exact testing ( p = 0.023), although the number of events was small and the distribution was non-monotonic. In multivariable Cox analysis, the CONUT score was independently associated with 1-year all-cause mortality (HR = 1.48, 95% CI: 1.33–1.65, p < 0.001), but not with readmission (HR = 1.05, 95% CI: 0.96–1.16, p = 0.281). For all-cause mortality, the AUC of CONUT was 0.760, significantly higher than that of GNRI (AUC = 0.668, p < 0.001) but not statistically different from that of PNI (AUC = 0.730, p = 0.251). All three tools showed limited discrimination for readmission (AUC range: 0.502–0.526). Conclusion The CONUT score was independently associated with 1-year all-cause mortality in adults with HFpEF and demonstrated significantly better discrimination than GNRI. Its discriminative performance was numerically higher than, but not statistically different from, that of PNI. CONUT may therefore serve as a practical supplementary tool for post-discharge risk stratification, although external validation is required.