Delayed cortical gray matter development in neonates with severe congenital heart disease

BACKGROUND: This study aimed to assess cortical gray matter growth and maturation in neonates with congenital heart disease (CHD).

METHODS: 31 (near) term neonates with severe CHD (8 univentricular heart malformation (UVH), 21 d-transposition of great arteries (d-TGA) and 2 aortic coarctation) underwent cerebral MRI before (postnatal-day 7) and after (postnatal-day 24) surgery. 18 controls with similar gestational age had one MRI (postnatal-day 23). Cortical gray matter volume (CGM), inner cortical surface (iCS) and median cortical thickness were extracted as measures of volumetric growth, and gyrification index (GI) as measure of maturation.

RESULTS: Over a median of 18 days CGM increased by 21%, iCS by 17%, thickness and GI both by 9%. Decreased post-operative CGM and iCS were seen for CHD compared to controls (p-values < 0.01), however with similar thickness and GI. UVH showed lower post-operative iCS, thickness (p-values < 0.05) and GI (p-value < 0.01) than d-TGA and controls. Infants requiring pre-operative balloon-atrioseptostomy (BAS, 61%) had reduced post-operative CGM, iCS and GI (p-values< 0.05).

CONCLUSIONS: Infants with severe CHD show reduced cortical volumes compared to controls with gyrification being delayed in UVH, but not in d-TGA. Infants requiring BAS show higher risk of impaired cortical volume and gyrification.