Association between Diastolic Function Parameters and MRI T2* Measurements in a Sample of Iranian Patients with Major Thalassemia

Abstract

<span><strong><em>Background: </em></strong><span>The aim of the present study was to investigate the relationship between the<span> echocardiographic indices of diastolic dysfunction and MRI T2* measurements, indicating<span> myocardial iron loadings, in patients with thalassemia major and normal left ventricular<span> ejection fractions.<br /><span><strong><em>Methods: </em></strong><span>A series of consecutive patients with known thalassemia major under treatment with<span> regular blood transfusions and iron chelation therapy were enrolled in the current study<span> between July 2012 and June 2015 at Baharlou Hospital, Tehran, Iran. All the patients<span> underwent cardiac MRI with the measurement of T2* for the liver and heart,<span> echocardiographic examination with tissue Doppler assessment, and serum ferritin assay.<span> The correlation between diastolic function parameters and T2* measurements was assessed<span> using statistical software. Standard diastolic indices, comprising early (E) and late (A)<span> transmitral peak flow velocities and early deceleration time (DT), were recorded.<br /><span><strong><em>Results: </em></strong><span>The mean E/A, mean E/E′, and mean E′ were 2.09±0.54, 0.07±0.011, and 14±1.40 cm/s,<span> respectively. The mean deceleration time (dt) was 190.97±35.89. The average serum ferritin<span> level was 1498±783.08 ng/mL (range =212.7 to >3000 ng/mL). The mean cardiac T2*<span> derived from MRI was 26.58±7.54 ms. The frequencies of the different severities of<span> myocardial iron loading based on myocardial T2* were as follows: 44 (80%) normal, 4<span> (7.3%) mild, 2 (3.6%) moderate, and 5 (9.1%) severe. MRI T2* did not have a significant<span> correlation with E/A (<span><em>r</em><span>=0.091; <span><em>P</em><span>=0.508), E′ (<span><em>r</em><span>=0.130; <span><em>P</em><span>=0.345), E/E′ (<span><em>r</em><span>=0.005; <span><em>P</em><span>=0.971),<span> and dt (<span><em>r</em><span>=0.028; <span><em>P</em><span>=0.838). Hepatic iron loading based on the MRI T2* values also did not<span> have any correlation with the echocardiographic indices of left ventricular diastolic<span> dysfunction—namely E/A (<span><em>r</em><span>=0.151; <span><em>P</em><span>=0.270), E′ (<span><em>r</em><span>=0.034; <span><em>P</em><span>=0.804), E/E′ (<span><em>r</em><span>=0.083;<br /><span><em>P</em><span>=0.547), and dt (<span><em>r</em><span>=0.128; <span><em>P</em><span>=0.351).<br /><span><strong><em>Conclusions</em></strong><span><em>: </em><span>None of the echocardiographic diastolic function parameters examined in this study<br /><span>were found to be suitable for cardiac surveillance in transfusion-dependent patients affected<br /><span>by thalassemia major. Longitudinal studies are needed to evaluate the utility of<br /><span>echocardiographic and MRI parameters to predict cardiac events. At the moment, we cannot<br /><span>recommend the replacement of cardiac MR and T2* measurements, indicating myocardial<br /><span>iron loading, by Doppler echocardiography in patients with a normal systolic function.</span></span></span></span></span></span></span></span></span><br /></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>