Association of impaired linear growth and worse neurodevelopmental outcome in infants with single ventricle physiology: a report from the pediatric heart network infant single ventricle trial

Objectives: To describe neurodevelopmental outcomes in infants with single ventricle (SV) physiology and determine factors associated with worse outcomes.

Study design: Neurodevelopmental outcomes for infants with SV enrolled in a multicenter drug trial were assessed at 14 months of age using the Bayley Scales of Infant Development-II. Multivariable regression analysis was used to identify factors associated with worse outcomes.

Results: Neurodevelopmental testing was performed at 14 ± 1 months in 170/185 subjects in the trial. Hypoplastic left heart syndrome was present in 59% and 75% had undergone the Norwood operation. Mean Psychomotor Developmental Index (PDI) and mental developmental index (MDI) were 80 ± 18 and 96 ± 14, respectively, (normal 100 ± 15, P < .001 for each). Group-based trajectory analysis provided a 2-group model ("high" and "low") for height z-score trajectory and brain type natriuretic peptide (BNP) trajectory. The predicted PDI scores were 15 points higher in the "high" height z-score trajectory compared with the "low" cluster (P < .001). A higher number of serious adverse events during the trial was associated with lower PDI scores (P = .02). The predicted MDI scores were 13-17 points lower in "low height trajectory-high BNP trajectory" group compared with the other 3 groups (P < .001). MDI scores were also lower in subjects who required extracorporeal membrane oxygenation during the neonatal hospitalization (P = .01) or supplemental oxygen at discharge (P = .01).

Conclusions: Neurodevelopmental outcome at 14 months of age is impaired in infants with SV physiology. Low height trajectory and high BNP trajectory were associated with worse neurodevelopmental outcomes. Efforts to improve nutritional status alone may not improve neurodevelopmental outcomes.