Abstract 8457: Early Neurodevelopmental Outcome in Hypoplastic Left Heart Syndrome and Related Anomalies: The Single Ventricle Reconstruction Trial

Abstract

Background: Children with HLHS and related anomalies who survive the Norwood procedure are at risk for neurodevelopmental (ND) impairment. We evaluated the relationship of ND outcome with type of Norwood shunt, patient factors, management practices, and medical course. Methods: In the Single Ventricle Reconstruction trial of the Norwood procedure with modified Blalock-Taussig shunt vs. right-ventricle-to-pulmonary-artery shunt, 14-month ND outcome was assessed using the Psychomotor Development Index (PDI) and Mental Development Index (MDI) of the Bayley Scales of Infant Development®-II. We used stepwise multivariable regression to identify risk factors for adverse ND outcome. Results: Among 373 transplant-free survivors, 321 (86%) returned for ND testing at age 14.3±1.1 (mean±SD) months. Mean PDI (74±19) and MDI (89±18) scores were lower than normative means (P<.001). Independent predictors of lower PDI score (R 2 = 26%) were center (P=.003), birth weight<2.5 kg (P=.023), longer Norwood hospitalization (P<.001), and more complications between Norwood procedure discharge and age 12 months (P<.001). Independent risk factors for lower MDI score (R 2 = 34%) included center (P<.001), birth weight<2.5 kg (P=.04), genetic syndrome/anomalies (P=.036), lower maternal education (P=.045), longer mechanical ventilation after the Norwood operation (P<.001), and greater number of complications after Norwood discharge to age 12 months (P<.001). We found no significant relationship of PDI or MDI score to type of Norwood shunt, perfusion type (i.e., deep hypothermic circulatory arrest, regional cerebral perfusion), other aspects of vital organ support (e.g., hematocrit, pH strategy); or cardiac anatomy including ascending aorta diameter. The relationship of predictors to ND outcome was similar in pre-specified subgroups of birth weight, preterm status, pre-Norwood head circumference, or genetic syndrome/other anomalies. Conclusion: ND impairment in Norwood survivors is more highly associated with innate patient factors and overall morbidity in the first year than with intraoperative management strategies. Improvement in ND outcome in this vulnerable population is thus likely to require interventions that occur outside the operating room.