Associations between anthropometric indices and outcomes of congenital heart operations in infants and young children: An analysis of data from the Society of Thoracic Surgeons Database.

Background: Children with congenital heart disease are at risk for growth failure due to inadequate nutrient intake and increased metabolic demands. We examined the relationship between anthropometric indices of nutrition (height-for-age z-score [HAZ], weight-for-age z-score [WAZ], weight-for-height z-score [WHZ]) and outcomes in a large sample of children undergoing surgery for congenital heart disease.

Methods: Patients in the Society of Thoracic Surgeons Congenital Heart Surgery Database having index cardiac surgery at age 1 month to 10 years were included. Indices were calculated by comparing patients' weight and height to population norms from the World Health Organization and Centers for Disease Control and Prevention. Outcomes included operative mortality, composite mortality or major complication, major postoperative infection, and postoperative length of stay. For each outcome and index, the adjusted odds ratio (aOR) (for mortality, composite outcome, and infection) and adjusted relative change in median (for postoperative length of stay) for a 1-unit decrease in index were estimated using mixed-effects logistic and log-linear regression models.

Results: Every unit decrease in HAZ was associated with 1.40 aOR of mortality (95% CI 1.32-1.48), and every unit decrease in WAZ was associated with 1.33 aOR for mortality (95% CI 1.25-1.41). The relationship between WHZ and outcome was nonlinear, with aOR of mortality of 0.84 (95% CI 0.76-0.93) for 1-unit decrease when WHZ ≥ 0 and a nonsignificant association for WHZ < 0. Trends for other outcomes were similar. Overall, the incidence of low nutritional indices was similar for 1-ventricle and 2-ventricle patients. Children between the age of 1 month and 1 year and those with lesions associated with pulmonary overcirculation had the highest incidence of low nutritional indices.

Conclusions: Lower HAZ and WAZ, suggestive of malnutrition, are associated with increased mortality and other adverse outcomes after cardiac surgery in infants and young children. Higher WHZ over zero, suggestive of obesity, is also associated with adverse outcomes.