Functional brain connectivity after corrective cardiac surgery for critical congenital heart disease: a preliminary near-infrared spectroscopy (NIRS) report

ABSTRACT

Patients with congenital heart disease (CHD) requiring cardiac surgery in infancy are at high risk for neurodevelopmental impairments. Neonatal imaging studies have reported disruptions of brain functional organization before surgery. Yet, the extent to which functional network alterations are present after cardiac repair remains unexplored. This preliminary study aimed at investigating cortical functional connectivity in 4-month-old infants with repaired CHD, using resting-state functional near-infrared spectroscopy (fNIRS). After fNIRS signal frequency decomposition, we compared values of magnitude-squared coherence as a measure of connectivity strength, between 21 infants with corrected CHD and 31 healthy controls. We identified a subset of connections with differences between groups at an uncorrected statistical level of p < .05 while controlling for sex and maternal socioeconomic status, with most of these connections showing reduced connectivity in infants with CHD. Although none of these differences reach statistical significance after FDR correction, likely due to the small sample size, moderate to large effect sizes were found for group-differences. If replicated, these results would therefore suggest preliminary evidence that alterations of brain functional connectivity are present in the months after cardiac surgery. Additional studies involving larger sample size are needed to replicate our data, and comparisons between pre- and postoperative findings would allow to further delineate alterations of functional brain connectivity in this population.

KEYWORDS:

• Congenital heart disease
• neurodevelopment
• resting-state functional connectivity
• NIRS
• brain function

Acknowledgments

We are grateful to all the patients and families who participated in this study. We would like to thank all the staff of the Clinique d’investigation neurocardiaque (CINC) of the Sainte-Justine University Hospital Center, Montreal, QC, Canada. We give particular credit to Lionel Carmant, MD, for his involvement in co-founding the CINC and his contribution to this study. In memory of our dear friend and outstanding pediatric neurologist Ala Birca, MD, PhD, with whom conversations always helped the interpretation of the results.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Heart and Stroke Foundation of Canada under grant number G-16-00012606 (AG), a Canada Research Chair in Clinical Child Neuropsychology and Brain Imaging #950–232661 (AG), the Quebec Bio-imaging Network (AG and SF), and the CHU Sainte-Justine Foundation (SF)