Iron deficiency in Syrian Children with Congenital Heart Diseases Its Association with Cyanotic Spells and Underweight, and the Usefulness of Erythrocyte Indices in Its Screening

Background and Objective: Congenital heart disease (CHD) represents a structural abnormality of the heart present from birth. It is classified into cyanotic lesions, which alter blood circulation and cause cyanosis, and acyanotic lesions. Many of these defects result in hypoxemia, which may in turn lead to iron deficiency, thereby increasing morbidity and mortality rates associated with such lesions. This study aims to assess iron deficiency among Syrian children with CHD, its relationship with the frequency of cyanotic spells and underweight, and the potential utility of complete blood count parameters in predicting iron deficiency.

Materials and Methods: A case-control study was conducted on 100 children (30 controls, 35 with acyanotic CHD, and 35 with cyanotic CHD). Inclusion criteria included children diagnosed with acyanotic defects such as ventricular or atrial septal defects, and those with tetralogy of Fallot or transposition of the great arteries, confirmed by two-dimensional echocardiography. Children who had undergone surgery, received iron supplements, or had hematologic diseases or infections were excluded.

Samples were collected from the Children's University Hospital and the Cardiac Surgery Hospital in Damascus after obtaining parental consent. The following tests were performed: complete blood count (CBC), serum iron, unsaturated iron-binding capacity (UIBC), and ferritin. Statistical analysis was conducted using SPSS version 16, employing various tests to determine differences and statistical relationships. A p-value < 0.05 was considered statistically significant.

Results: The results showed that patients in both cyanotic and acyanotic CHD groups had significantly lower ferritin levels compared to controls (p = <0.001, p = 0.042, respectively), indicating a marked reduction in iron stores. There was a statistically significant difference in serum iron levels between cyanotic and acyanotic patients (p = 0.028), and between cyanotic patients and controls (p < 0.001), whereas the difference between acyanotic patients and controls was not statistically significant (p = 0.053). The prevalence of iron deficiency was significantly higher in patients compared to controls (p = 0.002), with the highest rate (60%) observed in the cyanotic group. A moderate positive correlation was found between iron deficiency and increased frequency of cyanotic spells (Phi coefficient = 0.386), with the likelihood of these spells being 6.6 times higher among iron-deficient children (p = 0.02). An association was also found between iron deficiency and low weight in children with cyanotic CHD (p = 0.022). Logistic regression analysis showed that both red cell distribution width (RDW) and Mentzer index were good predictive markers of iron deficiency in children with cyanotic CHD.

Conclusions: The study indicates that children with congenital heart disease, particularly those with cyanotic defects, are more susceptible to iron deficiency, which is associated with increased frequency of cyanotic spells, weight loss, and worsened morbidity. Markers such as RDW and Mentzer index demonstrated predictive value for their iron deficiency.