Abnormal height and adiposity are observed after the Fontan operation. These abnormalities may be associated with worse functional outcome.

We analyzed data from the National Heart, Lung, and Blood Institute Pediatric Heart Network cross-sectional study of Fontan patients. Groups were defined by height (z-score <−1.5 or ≥−1.5) and body mass index (body mass index [BMI] z-score <−1.5 or −1.5 to 1.5 or ≥1.5). Associations of anthropometric measures with measurements from clinical testing (exercise, echocardiography, magnetic resonance imaging) were determined adjusting for demographics, anatomy, and pre-Fontan status. Relationships between anthropometric measures and functional health status (FHS) were assessed using the Child Health Questionnaire.

Mean age of the cohort (n = 544) was 11.9 ± 3.4 years. Lower height-z patients (n = 124, 23%) were more likely to have pre-Fontan atrioventricular valve regurgitation (P = .029), as well as orthopedic and developmental problems (both P < .001). Lower height-z patients also had lower physical and psychosocial FHS summary scores (both P < .01). Higher BMI-z patients (n = 45, 8%) and lower BMI-z patients (n = 53, 10%) did not have worse FHS compared to midrange BMI-z patients (n = 446, 82%). However, higher BMI-z patients had higher ventricular mass-to-volume ratio (P = .03) and lower % predicted maximum work (P = .004) compared to midrange and lower BMI-z patients.

Abnormal anthropometry is common in Fontan patients. Shorter stature is associated with poorer FHS and non-cardiac problems. Increased adiposity is associated with more ventricular hypertrophy and poorer exercise performance, which may have significant long-term implications in this at-risk population.