EVALUATING THE PREVALENCE AND FACTORS ASSOCIATED WITH AN OPTIMAL NEURODEVELOPMENTAL OUTCOME IN CHILDREN WITH FONTAN CIRCULATION

While youth with Fontan circulation are at increased risk for adverse neurodevelopmental outcomes, not all children encounter these limitations. We sought to evaluate the prevalence and factors associated with “optimal” neurodevelopmental outcomes in 4-6 year old children with Fontan circulation.

Patients who underwent the Fontan procedure born between September 1996 and December 31, 2015 and followed through the Western Canadian Complex Pediatric Therapies Follow-up Program (CPTFP) were included. All patients underwent a comprehensive neurocognitive assessment between 48-72 months of age. A composite outcome termed optimal neurodevelopmental outcome was defined as the absence of intellectual disability (full-scale intellectual quotient (FSIQ) < 80, visual motor index < 80, adaptive behavior assessment system, general adaptive composite < 80), chronic motor disability, permanent hearing loss, visual impairment, seizure disorder, or autism spectrum disorder. Multivariable regression models and decision algorithms (utilizing variables from the multivariable regression analysis, with cut-points determined to optimize a global accuracy index) were generated to evaluate demographic and clinical factors associated with optimal neurodevelopmental outcome. The Fontan procedure was completed on 225 children in the study period, with neurodevelopmental outcome data available for 205 (age at Fontan 3.4 +/- 0.9 years, age at assessment 4.6 +/- 0.5 years, 37% female). Optimal neurodevelopmental outcome was identified in 55% (112/205). In the multivariable regression analysis, factors independently associated with an increased odds ratio of optimal neurodevelopmental outcome were female sex [2.1 (95% confidence interval (CI) 1.1-4.1)], years of maternal schooling [1.2 (1.1-1.5)], age at Fontan (years) [0.97 (0.9-1.0)], need for concomitant atrioventricular valve (AVV) intervention [0.4 (0.2-1.0)], and time (hours) for lactate to be < 2mmol/L [0.9 (0.8-1.0)]. There was a wide range in the prevalence of optimal neurodevelopmental outcomes according to the presence or absence of clinical and demographic variables (Table). For example, if a patient was < 3.25 years at Fontan, did not have a concomitant AVV intervention, and the lactate was < 2mmol/L within eight hours post-operatively, 87% (27/31) had an optimal neurodevelopmental outcome. Conversely, the absence of each of these variables (>/=3.25 years, need for AVV intervention, and >/=8 hours to clear lactate) was associated with 7% (1/14) having optimal neurodevelopmental outcomes.

Optimal neurodevelopmental outcome was present in over half of 4-6 year old children with Fontan circulation in this single-center study, with important associated factors identified, including potentially modifiable factors such as younger age at Fontan and lack of concomitant AVV intervention. Multi-center evaluations are needed to further evaluate this previously undefined composite outcome.