Lower Child Opportunity Index is Associated with Lower Exercise Capacity Post-Fontan Palliation

Abstract Background The Child Opportunity Index (COI) is a validated measurement that uses a composite index of 29 indicators of social determinants of health linked to the US Census. Patients post-Fontan palliation for single ventricle often have reduced exercise capacity compared to the general population. Our hypothesis is that COI levels are directly associated with exercise capacity and inversely with late outcomes. Methods A retrospective, single-center study was performed, including 99 patients post-Fontan procedure who had cardiac magnetic resonance imaging at our institution from January 2010 to July 2023, of which 78 had undergone an exercise test. Univariate analysis was performed with Pearson correlational testing and multivariable linear regression was then used to evaluate independent predictors of % predicted VO₂. Results The mean age and sex were not different between the low and high COI groups (24.1 ± 8.5 y vs 22.5 ± 9.7 y; 34.5% vs 29.3% female). Patients with low COI had lower peak VO2 (25.7 vs 31.0 L/min/kg², p = 0.002) and % predicted peak VO2 (61.9 vs 71.4%, p = 0.003). At follow up post-Fontan (mean of 17.9 ± 7.4 y) there was one mortality and two heart transplants. There were more interventions in the low COI group (1.5 vs 0.9 intervention occurrence/patient, p = 0.038). There was no difference in hospital admissions or significant comorbidities between COI groups. Conclusion Lower COI was associated with worse exercise capacity in Fontan patients and may negatively impact the need for late interventions. This highlights the need for efforts to provide community resources to promote equity in cardiac outcomes.