Energy Intake and Expenditure in Children With Heart Failure.

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.

The miniaturized pediatric continuous-flow device: Preclinical assessment in the chronic sheep model.

BACKGROUND: The Infant Jarvik 2015 is an implantable axial-flow ventricular assist device (VAD) that has undergone the major evolutionary design modifications to improve hemocompatibility. This study was conducted in anticipation of data submission to the US Food and Drug Administration to obtain Investigational Device Exemption approval. METHODS: The VAD was implanted via a left thoracotomy in Barbado sheep (n = 10, 26 (19-34] kg). Anticoagulation was maintained with coumadin, with a target international normalized ratio of greater than the individual sheep's baseline values. The VAD was managed at the highest possible speed as clinically tolerable. Complete necropsy was performed at the end of the study. RESULTS: There were 2 early mortalities: tension pneumothorax (n = 1) and shower emboli of the fragmented myocardium (n = 1). The remaining 8 sheep (2 with 30-day and 6 with 60-day protocols) completed the anticipated study duration in excellent condition, with the 6 completing 60-day sheep showing appropriate weight gain during support. There were no signs of clinically significant hemolysis, with the final plasma-free hemoglobin of 2 (1-17) mg/dL. Necropsy showed old renal infarction in 7 sheep. Although thromboembolism can be the potential etiology, given the mild anticoagulation regimen, other sources of emboli were identified in 2 sheep (graft coating material and fragmented myocardium). Flow study demonstrated favorable increase in flow (up to 3.0 L/min) in proportion to change in pump speed. CONCLUSIONS: This study has demonstrated that the Infant Jarvik 2015 VAD is capable of maintaining its functionality for an extended period of time with minimal hemolysis.