Resting energy expenditure at 3 months of age following neonatal surgery for congenital heart disease

Abstract

Objective: Infants with Congenital Heart Disease (CHD) often exhibit growth failure. This can affect anthropometric and neurodevelopmental outcomes well into childhood. To determine the resting energy expenditure (REE), body composition, and growth in infants with CHD at 3 months of age, with the secondary aim to identify predictors of REE as compared with healthy infants.

Design and methods: This descriptive study is a subanalysis of a prospective study investigating predictors of growth in postoperative infants with CHD compared with healthy infants. Growth measurements, REE, and body composition were obtained in all infants. Analysis included chi-square for association between categorical variables, t-tests, ANOVA and ANCOVA. Outcome measures included the REE as determined by indirect calorimetry, anthropometric z-scores and body composition at 3 months of age.

Setting: Participants were recruited from the Cardiac Intensive Care Unit of a large, urban, pediatric cardiac center and pediatric primary care practices.

Results: The analysis included 93 infants, 44 (47%) with CHD. Of the infants with CHD, 39% had single ventricle (SV) physiology. There was no difference in REE related to cardiac physiology between infants with CHD and healthy infants or between infants with SV and biventricular (BV) physiology. Anthropometric z-scores for weight (-1.1 ± 1.1, P < 0.001), length (-0.7 ± 1.1, P < 0.05), and head circumference (-0.6 ± 1.2, P < 0.001) were lower in infants with CHD at 3 months of age. The percentage of body fat (%FAT) in postoperative infants with SV (24% ± 6, P = 0.02) and BV (23% ± 5, P < 0.001) physiology were lower than in healthy infants (27% ± 5), with no difference in REE.

Conclusion: At 3 months of age, there was no difference in REE between postsurgical infants with CHD and healthy infants. Infants with CHD had lower growth z-scores and %FAT. These data demonstrate decreased %FAT contributed to growth failure in the infants with CHD.

Keywords: Congenital Heart Disease; Growth Failure; Infant Growth; Resting Energy Expenditure.

Figure 1

Box plot graph of growth measures at 3 months of age. n for each group: SV = 17, BV = 27, Healthy= 49.

Figure 2

Regression line of REE kcal/day for fat-free mass (FFM), kg from TOBEC. Single Ventricle; Bi-ventricle; Healthy Controls The predicted line is calculated from an ANCOVA model using REE kcal/day as the dependent variable with FFM and physiology as independent variables.