Over the past twenty years, progress of cardiac surgery has been such that actual life expectancy of a patient with congenital heart disease (CHD) approaches that of the average for the general population. The current challenge is no longer to decrease cardiac surgery's mortality rate, but rather to manage morbidity and a child's overall development regarding nutrition and neurodevelopment. Malnutrition is a common cause of morbidity in infants with CHD, especially before the age of one. It can easily be explained by an increased metabolic demand linked to cardiac failure, hypoxemia or pulmonary hypertension. Secondly, food intake is frequently not optimal in this population and the infant's growth is insufficiently examined by paediatric cardiologists. Another factor is that much needed therapeutics such as diuretic drugs for example, often lead to weight loss. Ultimately, malnutrition in infants with CHD increases surgical risk, morbidity (infections, …), hospital stay, and alters long-term cognitive development.

This study reports prevalence and associated factors of malnutrition on short and long-term follow-up of a large cohort of patients with various CHD, and who underwent cardiac surgery before the age of one.

We conducted a retrospective and multicentre study that included infants from the North of France with CHD who underwent cardiac surgery before the age of one, between 2013 and 2017. To determine malnutrition, anthropometric measures (weight and height) were collected on the day of the surgery and during follow-up until 3 years after surgery to calculate Z-score for weight, height and weight/height. To test the statistical significance of the association between nutritional status and risk variables, univariate analysis was done applying Chi-square test. All variables significant at 0.1 in univariate analysis were included in the multivariate logistic regression analysis. The study was approved by French national ethic committee Commission national de l’informatique et des libertés (CNIL) and by the GFHGNP ethic committee (Groupe francophone d’hépatologie–gastro-entérologie et nutrition pédiatrique). The author declares that he has no competing of interest.

In total, 331 patients with CHD who underwent their first cardiac surgery (palliation or repair) before the age of one were included. Table 1 lists the cardiac diagnosis of patients included in the study. Demographic and clinical characteristics are summarised in Table 2. Caesarean section was performed in 23.5% of cases. Only 38% infants were breastfed after maternity stay. An important part of our population was treated with diuretic drugs before surgery for congestive heart failure (38.5%). 69 (21%) infants needed a gastric tube before surgery. Feeding difficulties (including need for dietary enrichment and/or presence of a gastric tube) represented 35% of our population at the day of surgery. Only 39 (12%) were specifically assessed by speech therapist for feeding problems.

Concerning surgery, 246 (74.5%) infants had undergone a biventricular repair, 51 (15.5%) infants had undergone a palliative intervention before a biventricular repair and 33 (10%) had a palliative intervention before a univentricular repair. 84 (26%) were cyanotic after their first surgery, 104 (32%) needed at least a second intervention. 49 (15%) infants had postoperative complications and 84 (26%) infants were treated by diuretics for congestive heart failure one month after surgery. 19 (5.9%) infants needed intravenous (IV) nutrition for more than 7 days. There were 19 (6%) deaths.

Regarding nutritional status, at the time of the surgery, 14% of the infants presented moderate to severe growth failure (with a Z score weight for age<−2SD) and 26% presented minor growth failure (with a Z scoreweight for age between −2 and −1 SD). Thus, 40% of our cohort presented minor to severe growth failure the day of the surgery. Regarding the ratio weight for height, 17% presented moderate to severe malnutrition (with a Z score weight for height<−2SD) and 30% minor malnutrition (with a Z scoreweight for height between −2 and −1 SD). Because we had a severe lack of data for height, percentages were calculated on 319 patients concerning growth failure and on 211 patients concerning malnutrition at the time of surgery. We thus, concentrated on growth failure in follow-up. At one month after surgery, 45% infants still presented feeding difficulties. Overall, 20 (6%) had a gastrostomy for feeding difficulties.

During follow-up, between six months and 12months after surgery, moderate to severe growth failure persisted in 16% of the study population and minor growth failure in 24%. In other terms, 40% of our cohort presented a persistent minor to severe growth failure. Fig. 1, Fig. 2 summarize evolution of growth failure and malnutrition respectively during follow-up from 15days to 3years after surgery. Nineteen patients died during follow-up. A significant proportion of patients had impaired somatic growth or malnutrition at the end of the follow-up.

Several associated factors of persistent growth failure 6 to 12months after surgery were identified in univariate analysis: prenatal diagnosis, presence of genetic syndrome, birth weight≤3kg, complex CHD (CHD with 2 or more significative lesions or double outlet right ventricule or single ventricule physiology), surgery after 30days from birth, and diuretic therapy before surgery and/or still necessary one month after surgery. The results of multivariate logistic regression analysis are summarized in Table 3. CHD types were divided in 4 groups regarding anatomy and complexity, using TGA, Fallot and coarctation of Aorta as referent CHD with low impact on infant growth away from the day of surgery. The presence of a feeding tube at the day of surgery was not associated with growth failure 6 to 12months after.

Growth failure in infants with CHD who undergo cardiac surgery before the age of one persists between 6 and 12months after surgery. This should be taken into account as it can have serious consequences on children's health and development. Highlighting predictive factors will allow medical staff to identify vulnerable infants at birth and during the period of surgery and therefore increase nutritional care to combat malnutrition and growth failure.