Neighborhood Social Vulnerability and Interstage Weight Gain: Evaluating the Role of a Home Monitoring Program

BACKGROUND: Poor interstage weight gain is a risk factor for adverse outcomes in infants with hypoplastic left heart syndrome. We sought to examine the association of neighborhood social vulnerability and interstage weight gain and determine if this association is modified by enrollment in our institution's Infant Single Ventricle Management and Monitoring Program (ISVMP). METHODS AND RESULTS: We performed a retrospective single‐center study of infants with hypoplastic left heart syndrome before (2007–2010) and after (2011–2020) introduction of the ISVMP. The primary outcome was interstage weight gain, and the secondary outcome was interstage growth failure. Multivariable linear and logistic regression models were used to examine the association between the Social Vulnerability Index and the outcomes. We introduced an interaction term into the models to test for effect modification by the ISVMP. We evaluated 217 ISVMP infants and 111 pre‐ISVMP historical controls. The Social Vulnerability Index was associated with interstage growth failure (P=0.001); however, enrollment in the ISVMP strongly attenuated this association (P=0.04). Pre‐ISVMP, as well as high‐ and middle‐vulnerability infants gained 4 g/d less and were significantly more likely to experience growth failure than low‐vulnerability infants (high versus low: adjusted odds ratio [aOR], 12.5 [95% CI, 2.5–62.2]; middle versus low: aOR, 7.8 [95% CI, 2.0–31.2]). After the introduction of the ISVMP, outcomes did not differ by Social Vulnerability Index tertile. Infants with middle and high Social Vulnerability Index scores who were enrolled in the ISVMP gained 4 g/d and 2 g/d more, respectively, than pre‐ISVMP controls. CONCLUSIONS: In infants with hypoplastic left heart syndrome, high social vulnerability is a risk factor for poor interstage weight gain. However, enrollment in the ISVMP significantly reduces growth disparities.