Background and objective: Myocardial iron deposition and cardiac failure in thalassemia major (TM) is the most serious reason of morbidity and mortality. Cardiac magnetic resonance imaging (MRI T2*) can indirectly quantified myocardial iron content. Moreover echocardiographic left ventricular diastolic evaluation in comparison to systolic evaluation is more sensitive to detect early myocardial dysfunction secondary to iron overload. The aim was to determine some diastolic and tissue Doppler echo indices correlated with cardiac MRI T2* to predict iron load.
Patients and methods: Thirty three TM patients (17F/16M) with history of 15 years transfusion or more were selected. They did cardiac MRI (CMR) with measurement of relaxation time of T2* and also echocardiographic examination with systolic and diastolic evaluation and tissue Doppler imaging.
Results: The mean value of cardiac T2* was 20.41 +/- 12.1 ms. Patients with abnormal T2* (< 20 ms) had abnormal ejection fraction (EF) in 10 (53.6%), and abnormal diastolic indices including deceleration time (DT), early (E) and late (A) transmitral peak flow velocity ratio (E/A), E/Em and Tei- index in 13 (72.2%), 12 (66.7%), 18 (100%) and 14 (77.8%) patients respectively. There was a good correlation between DT, Tei index and E/Em index with cardiac T2* values (p < 0.05, r = 0.70-0.81), poor correlation between E/A with T2* (p < 0.05, r = -0.44) and no significant correlation of liver T2* with cardiac T2* (p = 0.819).
Conclusions: In unequipped centres which CMR is not available because of good correlation between diastolic echocardiographic parameters and CMR T2*, the use of echocardiographic diastolic parameters for evaluation of cardiac state could be a replacing tool. In equipped centres we suggest doing CMR T2* as a first step examination in high risk patients, and then doing regular F/U with echocardiographic evaluation of diastolic and tissue Doppler echocardiographic parameters especially DT, E/Em and Tei index.