Objectives: Up to one third of children with heart failure exhibit growth failure. Limited data exists reporting energy requirements in this population. A study was designed to characterize the energy intake and total daily energy expenditure of children with heart failure using the doubly labeled water method.
Design: Prospective study using doubly labeled water to measure total daily energy expenditure in children with heart failure. Doubly labeled water was administered orally and daily urine samples collected for 10 days. Total daily energy expenditure was compared with historic data from age- and gender-matched healthy population. Anthropometrics and 3-day calorie count were also done.
Setting: The Cardiovascular Intensive Care Unit and Cardiology ward at Texas Children's Hospital.
Patients: Children with new presentation of heart failure as defined by an ejection fraction less than 35% and requiring inotrope(s) at the time of enrollment.
Measurements and main results: A total of five children with heart failure were enrolled from 2015 to 2016. All children showed weight-for-length less than mean-for-age. All had depressed myocardial function at enrollment, and all but one demonstrated improvement in ejection fraction at follow-up. Three had energy intake that met or surpassed their total daily energy expenditure, with total daily energy expenditure that measured below historic controls. One infant, despite supplementation, had an energy intake substantially below that of measured total daily energy expenditure and required cardiac transplantation.
Conclusions: Growth failure in heart failure is likely multifactorial and may be related to suboptimal energy intake secondary to exercise intolerance, malabsorption, and/or end-organ dysfunction due to impaired cardiac output. Doubly labeled water is a feasible method to assess total daily energy expenditure in children with heart failure.