Use of echocardiography and glutathione S-transferase to detect heart complications in β-thalassemic patients

Abo-Shanab, Assem M.; Kholoussi, Naglaa; Habib, Dawoud; Helwa, Iman A.; Hussin, Gehan; Omar, Naglaa; El-Kamah, Ghada; El-Dessouk, Mohamed; Fahmy, Abdelgawad

doi:10.4103/epj.epj_61_19

Use of echocardiography and glutathione S-transferase to detect heart complications in β-thalassemic patients

Authors

Abstract

Background and objective
β-Thalassemia major (TM) is an inherited disorder of hemoglobin synthesis and characterized by defective hemoglobin synthesis, resulting in ineffective erythropoiesis, severe anemia, increased erythrocyte turnover, and excessive iron absorption. Accordingly, iron overload develops and may accumulate in the liver, heart, and endocrine organs. Several gene polymorphisms have been studied as protective or predisposing factors for cardiac dysfunction in patients with TM. Moreover, echocardiographic left ventricular (LV) diastolic evaluation is used to detect early myocardial dysfunction secondary to iron overload. This study aimed at determining some diastolic and tissue Doppler echo indices to predict iron load.
Materials and methods
This study included 42 β-thalassemic patients, among whom, 16 proved to have cardiac complications after clinical evaluation. Their age ranged from 3 to 25 years. Participants were subjected to clinical evaluation, molecular analysis to detect glutathione S-transferase M1 (GSTM1) gene polymorphism, and transthoracic color Doppler echocardiography to detect early myocardial dysfunction.
Results
Seven (43.7%) patients had the functional wild-type allele (GSTM1 non-null genotypes), whereas nine (56.2%) patients were homozygous for the GSTM1 null allele. There was a statistically significant increase regarding both right and LV E/A in GSTM1 null genotype when compared with GSTM1 non-null genotype in β-thalassemic patients with cardiac complications. Moreover, LV and right ventricular diastolic function has been significantly affected in participants with GSTM1 null genotype in β-thalassemic patients with cardiac complications, and particularly, LV diastolic function has been significantly impaired in cases experiencing frequent blood transfusion in β-thalassemic patients with cardiac complications.
Conclusion
Follow-up of patients with β-thalassemia and evaluating echocardiographic changes may permit better assessment of patients and early recognition of cardiac affection before disease progression.

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