Cardiac Iron Overload by MRI in Children With B-Thalassemia Major and its Correlation With Cardiac Function by Echocardiography

Abstract

Background: Serial echocardiography is strongly recommended in asymptomatic B-thalassemia major (TM) patients for early detection of subtle cardiac dysfunction. T2*magnetic resonance imaging (MRI) is a noninvasive measurement of myocardial iron burden. Yet, it is not always available in many centers. Our study aimed to evaluate the myocardial function in TM patients using different echocardiographic modalities and to correlate these findings with cardiac T2*MRI. Patients and Methods: This is a cross-sectional study that was carried out on 140 children with a mean age of 10.9±3.7 years. One hundred children with TM and 40 healthy children were matched for age and sex as a control group. Serum ferritin, serum iron, and iron-binding capacity were measured. Cardiac iron overload was assessed by T2*MRI and cardiac function was assessed by echocardiography. The local ethics committee approved the study. Results: Among 100 children with TM, only 32% had cardiac iron overload of 8.525±5.45 detected by cardiac T2*MRI. Iron deposition correlated significantly with age. Markers of iron overload were significantly correlated with cardiac T2*MRI. There were significantly lower values of myocardial performance index, longitudinal strain, circumferential strain, area strain, and radial strain in TM patients compared with the controls (P<0.001). Only the myocardial performance index was correlated with T2*MRI. Conclusions: This study confirms that some parameters measured by tissue Doppler imaging such as the myocardial performance index could be useful for the early detection of cardiac impairment in asymptomatic TM patients when cardiac MRI is lacking. Further studies on a large scale to identify other parameters with high sensitivity are recommended.

Evaluation of electrocardiography, echocardiography and cardiac T2* for cardiac complications in beta thalassemia major

“…The presence of iron overload in 12 patients despite receiving iron chelation therapy regularly is an indicator of how susceptible patients with β-TM are to cardiac complications (table 2). Cardiac iron accumulation is generally increased in patients with β-TM due to frequent transfusions despite chelation therapy, and T2* MRI is used to show cardiac iron load [11,12,22,23]. Therefore, T2* MRI is performed once a year regularly as in our patients.…”

“…The multi-TE GRE sequence at different echo times of breath holding (TE 3,7,10,14,17,20,23, 26 and 29 msec) was used to detect cardiac iron accumulation. T2* MRI sequenced parameters were determined repetition time = 500 msec, FA = 20, slice thickness = 6mm, matrix = 128 x 256, FOV = 350 mm, 7 phased coding stage for each cardiac cycle and 15 to 25 sec acquisition time.…”

Global Longitudinal Strain for Detection of Cardiac Iron Overload in Patients with Thalassemia: A Meta-analysis of Observational Studies with Individual-Level Participant Data

“…Following the removal of duplicates, titles and abstracts of the remaining studies were investigated and irrelevant or ineligible records were eliminated. Finally, 14 studies with 789 thalassemia participants (310 and 430 with and without CIO respectively and 49 with undetermined condition) met all the eligibility criteria for the systematic review and meta-analysis (15)(16)(17)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) (Table-1 summarized their characteristics) (Figure -1). Eight studies with 405 patients with β-thalassemia accepted to share their data to be analyzed for IPD (12,15,17,21,22,24,30,31).…”

“…Cardiac magnetic resonance (CMR) imaging has been proposed as the most reliable and sensitive non-invasive tool to evaluate the iron level of myocardium (3)(4)(5) .Values of T2* less than 20 and 10 milliseconds are indicative of CIO and severe CIO, respectively. A study has estimated the prevalence of CIO in magnetic resonance imaging (MRI) to be 25% (6).…”

Global longitudinal strain for detection of cardiac iron overload in patients with thalassemia: a meta-analysis of observational studies with individual-level participant data

“…Therefore, early detection of cardiac iron overload (CIO) in the prevention of progressive heart failure is vital [1,2]. Cardiac magnetic resonance (CMR) imaging has been proposed as the most reliable and sensitive non-invasive tool to evaluate the iron level of myocardium [3][4][5]. Values of T2* less than 20 and 10 ms are indicative of CIO and severe CIO, respectively.…”