Processing Speed Partially Mediates Executive Function Impairments in Adolescents with Congenital Heart Disease: Results from a Prospective Cohort Study.

OBJECTIVE: To assess processing speed, fine motor function, attention, and executive function (EF) impairments in adolescents with complex congenital heart disease (CHD) who underwent open-heart surgery during infancy. STUDY DESIGN: We administered a comprehensive neuropsychological test battery evaluating 5 EF domains: working memory, inhibition, cognitive flexibility, fluency, and planning and primary neurodevelopmental processes (PNPs): processing speed, fine motor function, and attention. The sample included 100 adolescents with complex CHD from a previous University Children's Hospital Zurich study, with 104 healthy controls for comparison. We generated scores for each EF domain and computed an EF summary score. Group comparisons and associations were analyzed with multiple regressions accounting for parental education. Mediation analysis explored how PNPs mediate the effect between a CHD diagnosis and EF. RESULTS: In adolescents with complex CHD, all EF domains and the EF summary score were impaired (ß = 0.20 to 0.37, all P < .05). Furthermore, they exhibited slower processing speed (ß = 0.27, P < .01) than healthy controls, with no differences in attention (ß = -0.07, P = .34) and fine motor function (ß = 0.08, P = .34). Processing speed showed a strong association with the EF summary score (ß = 0.60, P < .001) and partially mediated the relationship between CHD diagnosis and the EF summary score (ß = 0.37, 95% CI [0.24, 0.50], P < .001). CONCLUSION: Adolescents with complex CHD show difficulties in EFs and processing speed. Notably, processing speed is strongly associated with EFs and partly accounts for EFs disparities between patients and healthy controls. Early detection and interventions for processing speed difficulties may improve EF outcomes in these patients.

Cohort and Individual Neurodevelopmental Stability between 1 and 6 Years of Age in Children with Congenital Heart Disease.

OBJECTIVE: To assess cohort and individual neurodevelopmental stability in children with congenital heart disease across childhood. STUDY DESIGN: The Reachout Study is a cohort study at the University Children's Hospital Zurich. Data from 148 children with congenital heart disease who underwent cardiopulmonary bypass surgery and 1-, 4-, and 6-year neurodevelopmental assessment were analyzed using mixed models. RESULTS: Cognitive and motor functions of the total cohort improved over time (cognitive: P = .01; motor: P <.001). The prevalence of children with cognitive impairment at age 6 years was 22.3%. Socioeconomic status showed a significant interaction with age on cognitive and motor development (cognitive: P <.001; motor: P = .001): higher socioeconomic status was associated with better neurodevelopmental outcome over time. Weight and head circumference at birth showed a significant interaction with age on motor development (weight: P = .048; head: P = .006). The correlation between test scores at different ages was weak to moderate (cognition: age 1-6 years: rho = 0.20, age 4-6 years: rho = 0.56, motor: age 1-6 years: rho = 0.23, age 4-6 years: rho = 0.50). CONCLUSIONS: Children with congenital heart disease show a mild improvement in cognitive and motor functions within the first 6 years of life, particularly those with higher socioeconomic status and larger head circumference and weight at birth. However, individual stability is moderate at best. Therefore, follow-up assessments are crucial to target therapeutic intervention effectively.

Neurodevelopmental Profiles of Children with Congenital Heart Disease at School Age.

OBJECTIVES: To assess 6-year neurodevelopmental outcomes in a current cohort of children with congenital heart disease (CHD) who underwent cardiopulmonary bypass surgery (CPB), and to determine risk factors for adverse outcomes. STUDY DESIGN: Outcomes were examined in 233 prospectively enrolled children with CHD (including 64 with a recognized genetic disorder) who underwent CPB between 2004 and 2009. Follow-up assessment included standardized neurologic, motor, and cognitive tests. Variables were collected prospectively, and multiple regression analysis was performed to determine independent risk factors for adverse outcome. RESULTS: The mean patient age at assessment was 6.3 years (range, 5.1-6.8 years). IQ was lower in children with a genetic disorder (median, 55; range, 17-115) compared with children without a genetic disorder (median, 95; range, 47-135; P < .001). Cognitive and motor performance also were lower in children without a genetic disorder compared with the norm (P < .01 for both). The prevalence of children without a genetic disorder performing below -2 SD (IQ 70) was higher than the norm (5.3% vs 2.3%; P = .008), and the prevalence of poor motor performance (<10th percentile) ranged from 21.2% to 41.1% (P < .01 for all). Significant independent risk factors for poor neurodevelopmental outcome included a genetic disorder, longer length of intensive care stay, lower birth weight, postoperative seizures, and lower socioeconomic status. CONCLUSIONS: Current cohorts of children with CHD undergoing CPB show favorable outcomes but remain at risk for long-term neurodevelopmental impairments, particularly those with a genetic disorder and a complicated postoperative course. Close neurodevelopmental surveillance is necessary to provide early therapeutic support.