Loss of Skeletal Muscle Mass Predicts Cardiac Death in Heart Failure with a Preserved Ejection Fraction but not Heart Failure with a Reduced Ejection Fraction

AIMS: Loss of skeletal muscle mass is an important determinant associated with poor long-term prognosis in patients with acute decompensated heart failure (ADHF). However, limited evidence is available. This study investigated the prognostic value of the psoas muscle mass index (PMI) in patients with ADHF. METHODS AND RESULTS: A total of 210 consecutive patients aged ≥60 years with ADHF were enrolled using a prospective database between 2015 and 2017. Primary endpoint was incidence of cardiac death. Cross-sectional psoas muscle area at the L3 vertebral level was obtained by computed tomography, and PMI was calculated by height. Reduced PMI was defined as a PMI below the 25th sex-specific percentile. Patients were also classified by their left ventricular ejection fraction (EF) as having either heart failure with a reduced ejection fraction (HFrEF, EF < 50%) or heart failure with a preserved ejection fraction (HFpEF, EF ≥ 50%). The median follow-up period was 1.8 years. There were 44 cardiac deaths (21%) during the study period. Patients with reduced PMI had significantly higher cardiac death rates than those with preserved PMI (33% vs. 17%, log-rank test P = 0.006). In subgroup analysis, HFpEF patients with reduced PMI had significantly higher cardiac death rates than those with preserved PMI (38% vs. 16%, log-rank test P = 0.006); conversely, HFrEF patients had comparable cardiac death rates regardless of their PMI group (27% for reduced PMI vs. 18% for preserved PMI, log-rank test P = 0.24). Multivariate Cox proportional hazards model revealed that patients with reduced PMI had a 2.3-fold higher risk of cardiac death compared with patients with preserved PMI (95% confidence interval 1.23-4.42, P = 0.01). CONCLUSIONS: Reduced PMI helps to predict long-term outcome in patients with HFpEF but not HFrEF.