CARDIOPULMONARY FITNESS AND PSYCHOSOCIAL FUNCTION IN FONTAN YOUTH

https://youtu.be/RRJyRKzY9xc INTRODUCTION: Youth with Fontan circulation frequently exhibit reduced exercise capacity and concerns with psychosocial function. However, the extent to which cardiopulmonary function relates to emotional and behavioral outcomes remains unclear. This study examined associations between key cardiopulmonary markers and psychosocial functioning using data from the Pediatric Heart Network (PHN) Fontan dataset. METHODS: Cross-sectional data were analyzed from a pediatric Fontan cohort (N = 402, 153 females, aged 12.40±3.21 years), from the Pediatric Heart Network Fontan public database. Cardiopulmonary variables included peak oxygen consumption (VO 2 peak in mL/kg/min), body surface area (BSA)-indexed oxygen pulse (BSA-indexed O 2 pulse in mL/beat/m2), chronotropic index, and ventilatory efficiency at anaerobic threshold (AT VE/VCO 2 ). Psychosocial outcomes were assessed using parent- and self-reported Child Health Questionnaire (CHQ) scores and emotional/behavioral concerns from the Congenital Heart Adolescent and Teenager (CHAT) questionnaire. Associations between cardiopulmonary fitness and psychosocial outcomes were examined using Pearson correlations. Predictors were evaluated using multiple linear regression models adjusted for age, sex, and puberty status. Independent-samples t-tests were then used to compare both cardiopulmonary and psychosocial outcomes between prepubertal (N = 129) and post-pubertal youth (N = 273). RESULTS: Higher AT VE/VCO 2 was associated with greater emotional concerns (r = .21, p = .001). Adjusted regression models found that AT VE/VCO 2 uniquely predicted emotional concerns (β = .17, p = .011). VO 2 peak, BSA-indexed O 2 pulse, and chronotropic index did not significantly predict emotional or behavioral outcomes after adjustment (p > .05). Pre-pubertal youth demonstrated higher AT VE/VCO 2 , t(297.5) = 5.41, p < .001 (Pre-pubertal: 45.15 ± 10.52; Post-pubertal: 39.74 ± 7.23), lower BSA-indexed O 2 pulse, t(220.6) = -2.89, p < .001 (Pre-pubertal: 5.34 ± 1.37; Post-pubertal: 5.81 ± 1.57) and fewer emotional concerns, t(223.8) = 2.09, p = .038 (Pre-pubertal: 23.28 ± 18.33; Post-pubertal: 19.10 ± 15.48), compared to post-pubertal youth. CONCLUSION: Higher AT VE/VCO 2 uniquely predicted greater emotional concerns in youth with Fontan circulation, whereas VO 2 peak and other traditional fitness measures did not. This suggests AT VE/VCO 2 may serve as a sensitive physiological indicator of emotional vulnerability in this population. Pre-pubertal youth with Fontan circulation showed higher AT VE/VCO 2 and lower BSA-indexed O 2 pulse, indicating developmental limitations in cardiovascular efficiency, while also reporting fewer emotional concerns than post-pubertal youth. Future research should investigate whether improving ventilatory efficiency, through targeted exercise training, respiratory muscle interventions, or medical procedures, will reduce emotional distress and enhance quality of life in Fontan youth.