The combination of skeletal muscle imaging and functional evaluation could predict the prognosis in nonischemic cardiomyopathy: A prospective observational study

Emerging evidence suggests that muscle quality plays a crucial role in determining the prognosis of patients with chronic heart failure (HF). However, few studies have explored the prognostic value of muscle quality using both structural and functional indicators. This study aimed to investigate whether a comprehensive assessment of muscle quality-evaluating both intramuscular fat (IMF) content and muscle-related neurotrophic factors-could enhance risk stratification in HF with reduced ejection fraction (HFrEF). We recruited 64 of 136 eligible HFrEF patients for this prospective study. We measured the percentage of IMF (%IMF) area in the thigh by computed tomography (CT) and the plasma brain-derived neurotrophic factor (BDNF) level as structural and functional aspects of muscle quality, respectively. The composite clinical endpoint was defined as cardiovascular (CV) death or unplanned rehospitalization due to cardiac events. In this study, correlation was not observed between %IMF and BDNF. Based on receiver operating characteristic (ROC) analysis, the optimal cutoff values of %IMF and BDNF to detect cardiac events were determined, and the patients were divided into 4 groups according to these values. No cardiac events occurred in the high BDNF-low %IMF group, but events occurred in 64.3% of the patients in the low BDNF-high %IMF group. Furthermore, adding plasma BDNF level and %IMF in the thigh to traditional risk factors of brain natriuretic peptide, estimated glomerular filtration rate (eGFR) and hemoglobin improved prognostic ability. A combined assessment of structural and functional muscle quality using %IMF and BDNF identifies subgroups with distinct cardiac event risks in patients with HFrEF. This dual-parameter approach may enhance risk stratification beyond conventional prognostic markers.