To define the baseline characteristics of long-term tube-fed (TF) single ventricle patients, investigate associations between long-term enteral tube feeding and growth, and determine associations with long-term outcomes after Fontan procedure.

We performed a retrospective cohort study of patients in the Australia and New Zealand Fontan Registry undergoing treatment at the Royal Children's Hospital, the Children's Hospital at Westmead, Royal Melbourne Hospital, and Royal Prince Alfred Hospital from 1981 to 2018. Patients were defined as TF or non-tube-fed (NTF) based on enteral tube feeding at the age of 90 days. Feeding groups were compared regarding body mass index (BMI) trajectory, BMI at last follow-up, and long-term incidence of severe Fontan failure.

Of 390 patients (56 [14%] TF, 334 [86%] NTF), TF was associated with right ventricular dominance, hypoplastic left heart syndrome, Norwood procedure, increased procedures prior to Fontan, extracardiac conduit Fontan, Fontan fenestration, and atrioventricular valve repair/replacement. TF patients were less likely to be in the higher compared with lowest 0-6 month BMI trajectory (P < .01; P = .03), had lower 6 month weight-for-age z-scores (P < .01) and length-for-age z-scores (P = .01). TF were less likely to be overweight/obese at pediatric follow-up (hazard ratio [HR] = 0.31, 95% CI: 0.12-0.80; P = .02) and more likely to be underweight at adult follow-up (HR = 16.51; 5% CI: 2.70-101.10; P < .01). TF compared with NTF was associated with increased risk of severe Fontan failure (HR = 4.13; 95% CI = 1.65-10.31; P < .01).

Prolonged infant enteral tube feeding is an independent marker of poor growth and adverse clinical outcomes extending long-term post-Fontan procedure.