Hypoplastic Left Heart Syndrome is not Associated with Worse Clinical or Neurodevelopmental Outcomes Than Other Cardiac Pathologies After the Norwood-Sano Operation

There is evidence to suggest that patients undergoing a Norwood for non-HLHS anatomy may have lower mortality than classic HLHS, but differences in neurodevelopmental outcome have not been assessed. Our objective was to compare survival and neurodevelopmental outcome during the same surgical era in a large, well-described cohort. All subjects who underwent a Norwood-Sano operation between 2005 and 2014 were included. Follow-up clinical, neurological, and developmental data were obtained from the Western Canadian Complex Pediatric Therapies Follow-up Program database. Developmental outcomes were assessed at 2 years of age using the Bayley Scales of Infant and Toddler Development (Bayley-III). Survival was assessed using Kaplan-Meier analysis. Baseline characteristics, survival, and neurodevelopmental outcomes were compared between those with HLHS and those with non-HLHS anatomy (non-HLHS). The study comprised 126 infants (75 male), 87 of whom had HLHS. Five-year survival was the same for subjects with HLHS and those with non-HLHS (HLHS 71.8%, non-HLHS 76.9%; p = 0.592). Ninety-three patients underwent neurodevelopmental assessment including Bayley-III scores. The overall mean cognitive composite score was 91.5 (SD 14.6), language score was 86.6 (SD 16.7) and overall mean motor composite score was 85.8 (SD 14.5); being lower than the American normative population mean score of 100 (SD 15) for each (p-value for each comparison, < 0.0001). None of the cognitive, language, or motor scores differed between those with HLHS and non-HLHS (all p > 0.05). In the generalized linear models, dominant right ventricle anatomy (present in 117 (93%) of patients) was predictive of lower language and motor scores. Comparative analysis of the HLHS and non-HLHS groups undergoing single ventricle palliation including a Norwood-Sano, during the same era, showed comparable 2-year survival and neurodevelopmental outcomes.