Physical function–dependent calf circumference thresholds for predicting 1-year mortality in older patients hospitalized with heart failure: a multicenter prospective cohort study

BACKGROUND & AIMS Calf circumference (CC) reflects muscle mass and nutritional status but may be confounded by peripheral edema in heart failure (HF). The Short Physical Performance Battery (SPPB) is a validated predictor of adverse outcomes in HF. This study developed and temporally validated a simple risk-stratification model combining SPPB and CC to predict 1-year mortality in hospitalized older patients with HF. METHODS We analyzed data from the Japanese multicenter J-Proof HF Registry, comprising 7362 patients aged ≥ 65 years. Participants were divided chronologically into training (n = 4417) and temporal validation (n = 2945) cohorts. Decision-tree analysis using SPPB and CC identified cutoff values and defined three mortality risk groups. Model performance was assessed using Kaplan-Meier analysis and multivariable Cox regression. RESULTS Patients were classified into low (SPPB ≥10 and CC ≥ 25.9 cm), intermediate (SPPB ≥10 and CC < 25.9 cm orSPPB 7-9 and CC ≥ 25.3 cm), and high (SPPB 7-9 and CC < 25.3 cm or SPPB < 7) risk groups. In the temporal validation cohort, 1-year survival differed significantly across groups (log-rank P < 0.001), with stepwise increases in adjusted mortality risk. Findings were consistent across sex subgroups. CONCLUSIONS The combined SPPB-CC model provides a simple approach for stratifying 1-year mortality risk in older patients hospitalized with HF. This bedside tool may help identify patients who could benefit from further nutritional and rehabilitation assessment.