Abstract 4120856: Abdominal Aortic Blood Flow and Interstage Growth and Neurodevelopment in Patients with Single Ventricle Heart Disease

Background: Achieving normal somatic growth and neurodevelopmental (ND) milestones is a common challenge for children with single ventricle heart disease (SV) prior to stage 2 palliation (S2P). This study aimed to characterize the potential association with poor splanchnic and cerebral circulations. Methods: This retrospective single centre study included SV patients born February 1, 2012, to May 30, 2022 who underwent MRI evaluation and S2P <12 months of age. Blood flow indices, including descending aorta flow (DAoNet), were measured by phase-contrast MRI. Primary outcomes were weight-for-age Z score (WFAZ) at S2P, and 18-month ND outcomes measured by Bayley Scales of Infant and Toddler Development 3rd Ed. Spearman’s correlation was used to model associations; statistical significance was considered for p<0.05. Results: A total of 144 patients were included: 61% (n=88) male, 12% (n=17) with genetic anomalies/syndrome, median (interquartile range) gestational age was 38.7 (38, 39.6) weeks, birth weight of 3.2 (2.8-3.6) kg, and birth WFAZ -0.23 (-1.1-0.6). Stage-1 palliation (n=130) was completed at 6 (3-23) days, 34% (n=49) for hypoplastic left heart syndrome, and S2P at 6.1 (5.3-7.1) months with a WFAZ of -1.4 (-2.3- (-0.5)). S2P WFAZ did not correlate with DAoNet (Figure 1), systemic cardiac output, or other blood flow indices. Lower S2P WFAZ was associated with lower birth WFAZ, and perioperative gastrointestinal complications. Lower 18-month motor development score was associated with lower birth WFAZ, native high pulmonary blood flow physiology, and indices of increase pulmonary blood flow: superior vena cava flow (b=8.8; [95% CI: 0.7 to17], p=0.03) and pulmonary venous to systemic blood flow (Qp:Qs) (b=-7, [95% CI: -11.1 to -2.9], p=0.001). Other ND domains were associated with lower birth WFAZ, not blood flow indices. Conclusion: In SV patients, DAoNet did not correlate with growth at S2P. Modifiable factors studied were not associated with somatic growth. DAoNet, superior vena cava flow, and Qp:Qs were associated with 18-months motor development, which may indicate long-term risks of high pulmonary blood flow. Studies are needed to delineate the pathophysiology by which these findings are mediated.