There is very little information available on the neurodevelopmental status of Indian children with CHD. The only Indian study on the topic has addressed neurodevelopmental outcome of infants after cardiac surgery [5]. Thus, the present study was conducted to study the neurodevelopmental status of children with congenital heart disease and elucidate associated factors.

This descriptive study was conducted from June 2013 to January 2014 in the Pediatrics department of Lok Nayak hospital, Maulana Azad Medical College, Delhi, after obtaining clearance from the Institutional Ethics Committee. With an expected 25% prevalence of developmental delay in children with CHD, with a 90% precision and 95% confidence, a sample size of 72 was calculated. We planned to enroll 75 children, expecting a 5% loss to follow-up between stabilization and developmental assessment.

All consecutive children in the age group of 6 to 30 month who presented with symptoms and signs suggestive of congenital heart disease, which was confirmed by echocardiography, were approached for inclusion after initial management and stabilization of the child. Children with clinically recognizable genetic syndromes or disorders e.g., Down, Alagille, Turner or Noonan syndrome and VACTERL association; Visual and/or hearing deficits; microcephaly; and, those who were post-cardiac surgery were excluded. Parents were explained about the purpose of the study and a written informed consent was obtained. This process was continued till the a priori sample size of 75 children was achieved.

Clinical severity of lesion was classified as per criteria suggested by Hoffman and Kaplan [7]. Children were classified as low-, moderate- and high-risk groups for developmental delay based on criteria given by American Heart Association [4]. Appropriate inter-ventions were provided at the Child Development Centre of our institution for all children with developmental delay; and early intervention provided to those in high-risk categories for developmental delay [8].

Statistical analysis: Data were entered in Excel spreadsheets and analyzed using SPSS 16.0 by a statistician. Various anthropometric and clinical factors were compared between CHD patients with or without neurodevelopmental delay by the Chi-square test or Fischer exact test. Mean DQ was compared between cyanotic and acyanotic groups by the Student’s t test, and between risk and severity groups by Anova. A P-value less than 0.05 was considered significant.

A total of 2105 children in the described age-group attended the hospital during the study period, of which 75 children (51 acyanotic CHD) were enrolled (Fig. 1). Majority of children (62.6%) in the study group were in the younger age group (6-12 month), with 29.4% older than 18 months. 57.3% had weight <-3 Z score of WHO charts; although there were no age, sex or anthropometric differences between children with cyanotic or acyanotic CHD. Ventricular septal defect was the commonest acyanotic CHD (47%) and Tetralogy of Fallot was the commonest cyanotic CHD (25%) (Table I).

Fig.1 Flow of participants in the study.

TABLE I	Characteristics of Children With Congenital Heart Disease (N=75)

TABLE II Developmental Status in Children With Congenital Heart Disease (N=75)

TABLE III	Developmental Status in Children With Congenital Heart Disease Based on Severity 
Classification and Risk Stratification (N=75)#

The mean Motor DQ was significantly lower in the cyanotic group than acyanotic group (P=0.048). However, mean Mental DQ was not different among acyanotic and cyanotic CHD groups (P=0.92) or according to type of acyanotic CHD (P = 0.44) (Table II). Delayed motor development was seen in 75% children with cyanotic CHD and 35.3% with acyanotic CHD (P=0.001) (Table II). The motor DQ was also found to be significantly affected by type of ACHD (P = 0.018), with lower motor DQ in large VSD and complex acyanotic CHD. DQ was not different among various type of cyanotic CHD (P=0.223 and 0.526 for mean Motor and Mental, respectively) (Data not shown).

All cyanotic CHD children were in severe group (Table III). As per AHA risk stratification for developmental delay, 35(68%) children were in low and 15 (29%) in moderate risk group among acyanotic CHD. Among cyanotic CHD, 16 (66%) were in moderate risk group and 8 (33%) in high risk group. As expected, motor DQ was found to be significantly lower in the severe group (P=0.01), whereas mental DQ was not much different across either the severity groups or the risk categories (Table III).

Neurological abnormalities were found in 6 children, among which 3 children were in high risk category. Most common neurological abnormality found was hypotonia (5 children). USG cranium was normal in all children.

The limitations of the present study include smaller number of cyanotic CHD children, lack of non-CHD controls, lesser number of patients in the older age-groups, and absence of follow-up after surgery/control of cardiac failure. There are other psychosocial factors that may have a negative impact on these children including physical restriction, parental overprotection, school absence, and decreased peer-interaction, which were not studied.

Nearly half the children (57.3%) had weight <-3 SD of WHO growth chart. Malnutrition in infants with CHD is related to increased energy expenditure and inadequate caloric intake for growth [9]. Mean motor DQ was decreasing with the severity, which was in accordance to previous studies [10] stating that developmental delay increases with the complexity of heart disease. Stratification based on risk for developmental delay has been given by American Heart Association [4]. We found low DQ in high risk groups in all domains compared to moderate- and low-risk groups.

More developmental delay was found in CCHD group in various previous studies due to chronic hypoxia caused by underlying CHD [7]. In a previous study [11] of neurodevelopmental status of newborns and infants with congenital heart disease before and after open heart surgery, newborns with acyanotic defect were more likely to demonstrate neurologic abnormality than those with cyanotic defect. In another study [12] from Canada, gross and/or fine motor delay was documented in 42%, and 23% had global developmental delay. Higher number of children with developmental delay in our study compared to these studies could be due to the high prevalence of uncontrolled CHF; anemia and rickets may also contri-bute to the same. Similar to our study, others have also found that motor delay is more than mental delay among children with CHD [13,14].

The high rate of developmental delay among children with CHD demonstrated in this study has important implications for practice and research. Future studies need to identify modifiable factors affecting development among these group of children in addition to those previously identified (e.g., congestive cardiac failure and anemia). Screening and evaluation of developmental delay in pediatric CHD population are essential steps to guide appropriate interventions to maximize their overall development.

Contributors: DM: conceived and planned the study, and supervised the conduct of the study and preparation of the manuscript. KL: enrolled subjects, did the neurodevelopmental assessment, analyzed data, and prepared the initial draft of the manuscript. VM: echocardiographic studies. MJ: supervised the neurodevelopmental assessment. VM and MJ: assisted in the planning of the study and preparation of the manuscript. All authors approved the final manuscript for publication.

Funding: None; Competing interest: None stated.