Skeletal muscle mass and overhydration are associated with in-hospital mortality in acute heart failure patients

OBJECTIVE: The aim of the study was to determine the association between low muscle mass and abnormal fluid distribution with in-hospital mortality in patients with acute heart failure. METHODS: In a prospective cohort study at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubiran in Mexico City, patients with acute heart failure who underwent thoracic or abdominal computed tomography within 72 h before or after admission between September 2017 and July 2024 were included. The exclusion criteria were an illegible computed tomography scan, an incorrect bioimpedance analysis lecture, the presence of cancer, COVID-19, chronic kidney disease with renal replacement therapy, or dismissal of a diagnosis of acute heart failure. Bioelectrical impedance analysis was performed within the first 24 h of hospitalization to measure phase angle and impedance ratio for evaluating hydration status. The skeletal muscle area was measured using a single axial slide at L3 for abdominal computed tomography and the T4 level for thoracic computed tomography. RESULTS: This study included 134 patients, with an overall hospital survival rate of 83.6%. The mortality group had a lower abdominal skeletal muscle area (86.5 vs. 111 cm2, p=0.024), smaller pectoral skeletal muscle area (18.9 vs. 26 cm2, p=0.005), lower phase angle (3 vs. 3.9, p=0.010), increased impedance ratio (0.89 vs. 0.86, p=0.002), greater prevalence of reduced pectoral muscle mass (40.9 vs. 12.5%, p