Cognitive and Executive Function in Congenital Heart Disease: A Meta-analysis

CONTEXT: Cognitive function and executive function (EF) impairments contribute to the longterm burden of congenital heart disease (CHD). However, the degree and profile of impairments are insufficiently described. OBJECTIVE: To systematically review and meta-analyze the evidence on cognitive function and EF outcomes in school-aged children operated for CHD and identify the risk factors for an unfavorable outcome. DATA SOURCES: Cochrane, Embase, Medline, and PsycINFO. STUDY SELECTION: Original peer-reviewed studies reporting cognitive or EF outcome in 5- to 17year old children with CHD after cardiopulmonary bypass surgery. DATA EXTRACTION: Results of IQ and EF assessments were extracted, and estimates were transformed to means and SE. Standardized mean differences were calculated for comparison with healthy controls. RESULTS: Among 74 studies (3645 children with CHD) reporting total IQ, the summary estimate was 96.03 (95% confidence interval: 94.91 to 97.14). Hypoplastic left heart syndrome and univentricular CHD cohorts performed significantly worse than atrial and ventricular septum defect cohorts (P =.0003; P =.027). An older age at assessment was associated with lower IQ scores in cohorts with transposition of the great arteries (P =.014). Among 13 studies (774 children with CHD) reporting EF compared with controls, the standardized mean difference was -0.56 (95% confidence interval: -0.65 to -0.46) with no predilection for a specific EF domain or age effect. LIMITATIONS: Heterogeneity between studies was large. CONCLUSIONS: Intellectual impairments in CHD are frequent, with severity and trajectory depending on the CHD subtype. EF performance is poorer in children with CHD without a specific EF profile. The heterogeneity in studied populations and applied assessments is large. A uniform testing guideline is urgently needed.