Reduced cerebrovascular reactivity is more pronounced in female than male youth with complex congenital heart defects

Congenital heart defects (CHD) are the most common type of neonatal malformation. Neonates with complex CHD present with cerebrovascular dysfunction, including deficits in cerebrovascular reactivity (CVR), a measure of vascular reserve. However, it is unknown whether these deficits persist beyond the perioperative period. Here, we compared CVR between 53 youth with CHD and 54 age-matched controls without CHD. We found that youth with CHD present with relative CVR deficits in the whole grey matter and in the anterior cerebral artery territory when compared to controls. Important sex differences were identified in the middle cerebral artery territory, with females having lower relative CVR than males in the CHD group. Severity of CHD also had an impact on CVR, with greater deficits in individuals with single-ventricle as compared to two-ventricle physiology. Finally, in the CHD group, a lower CVR was found to be associated with reduced performance on the Metacognitive Abilities Index. These results support that cerebrovascular deficits in CHD survivors are persistent and that CVR offers great promise as a biomarker of cognitive difficulties, which could be targeted in future interventions.