The Association Between Preoperative Malnutrition and Early Postoperative Outcomes in Children with Congenital Heart Disease: A 2-Year Retrospective Study at a Lebanese Tertiary Medical Center

Abstract

Objectives: This study aimed to describe the prevalence of malnutrition and its impact on postoperative outcomes in infants and children with congenital heart diseases (CHDs) undergoing cardiac surgeries.

Methods: We conducted a single-center, retrospective review of medical records of children aged 1 month to 5 years with CHDs who underwent cardiac surgery at the American University of Beirut Medical Center (AUBMC) between January 2015 and January 2017. Anthropometric data were collected and z-scores for weight-for-age (WAZ), height-for-age (HAZ), weight-for-height (WHZ), and BMI-for-age were calculated. Malnutrition was classified based on the World Health Organization (WHO) definitions and the American Society for Parenteral and Enteral Nutrition (ASPEN) criteria. The postoperative outcomes were analyzed using bivariate and multivariable models.

Results: The prevalence of malnutrition was 33.8%, with children younger than 24 months having significantly higher odds of malnutrition. The most common CHDs were ventricular septal defect (VSD) and tetralogy of Fallot (TOF), with malnutrition being significantly more prevalent in the children with VSD. Malnutrition was significantly associated with a prolonged pediatric intensive care unit (PICU) stay, with underweight being the strongest predictor. Malnourished children also had a significantly longer mechanical ventilation time (median 9.0 vs. 5.0 h, p = 0.017). Lower weight-for-age (WAZ) and BMI-for-age z-scores were associated with longer hospital stay, PICU stay, and mechanical ventilation durations.

Conclusions: Malnutrition is prevalent among children with CHDs and is independently associated with longer hospital and PICU stays, as well as extended mechanical ventilation. Early nutritional assessment and intervention may improve postoperative outcomes in this vulnerable population.

Keywords: congenital heart diseases; infants and children; malnutrition; postoperative outcomes; stunting; underweight; wasting.

Figure 1

Flow diagram of the study design. * Biologically implausible values (BIVs) were defined, according to World Health Organization (WHO) Multicenter Growth Reference Study Group 2006, as height-for-age z-score (HAZ) below –6 SD or above +6 SD, weight-for-height z-score (WHZ) below –5 SD or above +5 SD, and weight-for-age z-score (WAZ) below –6 SD or above +5 SD.

Figure 2

Malnutrition by congenital heart diseases. TOF: tetralogy of Fallot, VSD: ventricular septal defect, ASD: atrioventricular septal defect, GA: transposition of great arteries, AVC: atrioventricular canal defect, TAPVR: toral anomalous pulmonary venous return, PAPVR: partial anomalous pulmonary venous return. The stacked bar chart shows the count of each congenital heart disease (CHD), with blue color representing the percentage of subjects with normal nutritional status within each category of CHD, and the orange color representing the percentage of malnourished subjects.

Figure 3

The distribution of anthropometric z-scores. HAZ: height-for-age z-score, WAZ: weight-for-age z-score, WHZ: weight-for-height z-score, BMI: body mass index (calculated only for children ≥24 months old). WHZ could not be calculated for one patient as weight-for-height charts are available only for heights between 77 and 121.5 cm.

Figure 4

Outcomes (in-hospital mortality, infection, prolonged LOS > 7 days, PICU stay > 3 days and MV time ≥ 48 h) by malnutrition indicator (stunting (A), wasting (B), and underweight (C)). Pearson’s Chi-Square test was used (no expected counts less than 5). LOS: length of hospital stay; PICU: pediatric intensive care unit; MV: mechanical ventilation.

Figure 5

Adjusted odds ratio of infection (A), prolonged LOS (B), prolonged PICU stay (C), and inotrope use (D) by malnutrition indicator. Models were adjusted for age at time of surgery, gender, and RACHS-1 categories. LOS: length of hospital stay; PICU: pediatric intensive care unit; aOR: adjusted odds ratio; CI: confidence interval.