Factors Affecting Growth in Infants with Single Ventricle Physiology: A Report from the Pediatric Heart Network Infant Single Ventricle Trial

Objectives To describe growth patterns in infants with single ventricle physiology and determine factors influencing growth. Study design Data from 230 subjects enrolled in the Pediatric Heart Network Infant Single Ventricle Enalapril Trial were used to assess factors influencing change in weight-for-age z-score (∆z) from study enrollment (0.7 ± 0.4 months) to pre-superior cavopulmonary connection (SCPC; 5.1 ± 1.8 months, period 1) and pre-SCPC to final study visit (14.1 ± 0.9 months, period 2). Predictor variables included patient characteristics, feeding regimen, clinical center, and medical factors during neonatal (period 1) and SCPC hospitalizations (period 2). Univariate regression analysis was performed, followed by backward stepwise regression and bootstrapping reliability to inform a final multivariable model. Results Weights were available for 197 of 230 subjects for period 1 and 173 of 197 subjects for period 2. For period 1, greater gestational age, younger age at study enrollment, tube feeding at neonatal hospitalization discharge, and clinical center were associated with a greater negative ∆z (poorer growth) in multivariable modeling (adjusted R2 = 0.39, P < .001). For period 2, younger age at SCPC and greater daily caloric intake were associated with greater positive ∆z (better growth; R2 = 0.10, P = .002). Conclusions Aggressive nutritional support and earlier SCPC are modifiable factors associated with a favorable change in weight-for-age z-score.