ABSTRACT: Aims and Objectives: Malnutrition is common in children with congenital heart disease and may contribute to adverse outcomes. This study evaluates the impact of pre-operative nutritional status on outcomes after congenital heart surgery. Methods: We conducted a retrospective cohort study enrolling children under 10 years old who underwent congenital heart surgery at a tertiary children's hospital from 2012 to 2016. Patients who had patent ductus arteriosus ligation only, genetic syndromes, or global developmental delay were excluded. Outcome measures included 30-day mortality, intensive care unit (ICU) length of stay (LOS), hospital LOS, duration of mechanical ventilation, and number of inotropes used post-operatively. We performed univariate/multivariable logistic regression analysis, adjusting for age, cyanotic cardiac lesion, co-morbidity, and Risk Adjustment for Congenital Heart Surgery (RACHS-1) score. Results: Three hundred two children of median age 16.2 [interquartile range (IQR) 3.1, 51.4)] months were included. The most common cardiac lesions were ventricular septal defect (27.8%), atrial septal defect (17.9%), and Tetralogy of Fallot (16.6%). Median weight-for-age z-score (WAZ) was -1.46 (IQR -2.29, -0.61), height-for-age z-score (HAZ) was -0.94 (IQR -2.10, -0.10), and body mass index (BMI)-for-age z-score (BAZ) was -1.11 (IQR -2.19, -0.30). In multivariable analysis, there was an increased risk of 30-day mortality for WAZ ?-2 vs. WAZ >-2 [adjusted odds ratio (aOR): 4.01, 95% CI: 1.22, 13.13; p = 0.022]. For HAZ ?-2 vs. HAZ > -2, there was increased risk of hospital LOS ? 7 days (aOR: 2.08, 95% CI: 1.12, 3.89; p = 0.021), mechanical ventilation ?48 h (aOR: 2.63, 95% CI: 1.32, 5.24; p = 0.006) and of requiring ?3 inotropes post-operatively (aOR: 3.00, 95% CI: 1.37, 6.59; p = 0.006). Conclusion: In children undergoing congenital heart surgery, WAZ ? -2 is associated with higher 30-day mortality, while HAZ ? -2 is associated with longer durations of hospital LOS and mechanical ventilation, and increased risk of use of 3 or more inotropes post-operatively. Future studies are necessary to develop safe and efficacious peri-operative nutritional interventions, particularly in patients with WAZ and HAZ ? -2.
