Introduction: Malnutrition is an important complication of end-stage heart failure (HF) but is difficult to assess reliably in children because of fluid overload. In adults, CT has been used to measure muscle mass to assess muscle loss (sarcopenia), a method that is independent of fluid status.
Hypothesis: Skeletal muscle index as defined by CT is lower for children with end-stage HF compared to age, gender and race-matched healthy controls.
Methods: All children undergoing formal evaluation for heart transplant (HT) at Stanford University between 2013 and 2016 were identified using a hospital database. Skeletal Muscle Index (SMI) was calculated using a single CT plane at L-3 where the cross sectional area of the psoas muscle is measured. Malnutrition severity was defined using criteria adapted from the American Society for Parenteral and Enteral Nutrition (ASPEN). The Wilcoxon signed rank test was used to compare SMI between paired subjects and healthy controls matched for age, gender and race.
Results: A total of 36 children who met the study eligibility criteria were included for analysis. Patients had a median age of 9 years (IQR, 4.7-13.4), a median weight of 21.6 kg (IQR, 13.9-34.4); and 86% had congenital heart disease (CHD). Overall, 17% met criteria for mild malnutrition, 33% for moderate malnutrition, 25% for severe malnutrition, while 25% were categorized as non-malnourished. Among those who were malnourished, SMI was significantly lower for children with HF than their matched non-malnourished normal controls (27 pairs, p<0.001), whereas for non-malnourished patients (normal, overweight or obese), SMI was not significantly different compared to their matched non-malnourished normal controls (9 pairs, p=0.43).
Conclusions: Malnourished children with end-stage heart failure appear to have significantly lower skeletal muscle mass than healthy controls. Evaluation of sarcopenia using the skeletal muscle index appears to be a promising method to evaluate nutritional status objectively in children with end-stage heart failure that is independent of volume status.