Longitudinal study of anthropometry in Fontan survivors: PHN Fontan study short title: Anthropometry in Fontan survivors

Background Growth abnormalities in single-ventricle survivors may reduce quality of life (QoL) and exercise capacity. Methods This multicenter, longitudinal analysis evaluated changes in height and body mass index (BMI) compared to population norms and their relationship to mortality, ventricular morphology, QoL, and exercise capacity in the Pediatric Heart Network Fontan studies. Results Fontan 1 (F1) included 546 participants (12 +/- 3.4 years); Fontan 2 (F2), 427 (19 +/- 3.4 years); and Fontan 3 (F3), 362 (21 +/- 3.5 years), with similar to 60% male at each time point. Height z-score was -0.67 +/- -1.27, -0.60 +/- 1.34, and - 0.43 +/- 1.14 at Fl-F3, lower compared to norms at all time points (P <= .001). BMI z-score was similar to population norms. Compared to survivors, participants who died had lower height z-score (P <= .001). Participants with dominant right ventricle (n = 112) had lower height z-score (P <= .004) compared to dominant left (n = 186) or mixed (n = 64) ventricular morphologies. Higher height z-score was associated with higher Pediatric Quality of Life Inventory for the total score (slope = 2.82 +/- 0.52; P <= .001). Increase in height z-score (F1 to F3) was associated with increased oxygen consumption (slope = 2.61 +/- 1.08; P = .02), whereas, for participants >20 years old, an increase in BMI (F1 to F3) was associated with a decrease in oxygen consumption (slope = -1.25 +/- 0.33; P <= .001). Conclusions Fontan survivors, especially those with right ventricular morphology, are shorter when compared to the normal population but have similar BMI. Shorter stature was associated with worse survival. An increase in height z-score over the course of the study was associated with better QoL and exercise capacity; an increase in BMI was associated with worse exercise capacity.