Comparison of diastolic function in children with transfusion dependent beta thalassemia major by tissue and conventional doppler imaging indices and its correlation with serum ferritin levels

Özet

Regular blood transfusions for children with beta thalassemia major (βTM) results in iron overload cardiomyopathy/cardiac failure. Mortality inthese children is most often because of heart failure. We compared TissueDoppler Imaging (TDI) and conventional pulse wave Doppler (PWD) indicesin evaluating diastolic function in chronically transfused β-TM children andcorrelated the Doppler indices with mean serum ferritin levels.This was a prospective cross-sectional study conducted at tertiary teachinghospital. β-TM children aged 3 to 18 years were enrolled as per inclusioncriteria. PWD parameters at the mitral inflow (E, A, E/A and DT) and TDIparameters at the medial mitral annulus (Eʹand E/Eʹ) were used for estimationof diastolic dysfunction.Of the 66 children with thalassemia, the mean age was 10.2±3.77yrs and60.6% were boys. The E/Eʹ ratio estimated diastolic dysfunction (34/66, 51.5%)greater than four times that assessed by E/A ratio indices (8/66, 12.1%) inthe subjects. Association of serum ferritin levels with E/Eʹ ratio by chi squaretest was significant statistically (P=0.027), however was not significant withE/A ratio. By Mann Whitney test, the median serum ferritin levels (ng/ml)were higher [4034.50, (IQR-2084-5340.25) in those with diastolic dysfunction(abnormal E/Eʹ), when compared to those with normal E/Eʹ[2037.50(1510.75-3572.25)], with their difference being significant (p=0.011), however serumferritin levels were not significant with E/A ratio and DT. E/Eʹ parameterhad a sensitivity and specificity of 76.5% and 53.1% respectively at a meanserum ferritin cutoff level of 2076 ng/mL by ROC analysis.In conclusion, TDI is a more reliable modality for diagnosing early diastolicdysfunction when compared to PWD. Threshold level of serum ferritin greaterthan 2076 ng/mL is associated with increased incidence of diastolic dysfunction.