Detection of myocardial iron overload by two-dimensional speckle tracking in patients with beta-thalassaemia major: a combined echocardiographic and T2* segmental CMR study

Abstract

We aimed to evaluate the role of two-dimensional speckle tracking imaging (2DSTI) in detecting early changes of myocardial deformation in patients affected by thalassemia major (TM) and its relation with myocardial iron overload (MIO) detected by T2* cardiovascular magnetic resonance (CMR). We studied 28 TM patients (15 males, 37.4 ± 10 years). All patients underwent CMR and echocardiography in the same day. Segmental and global T2* values were measured. Values of global longitudinal strain (GLS) were derived from the three apical views, while radial and circumferential strain were obtained as average strain from the short axis views at basal, mid and apical level. Six patients (21.4%) showed significant MIO (global heart T2* < 20 ms). GLS showed a significant correlation with T2* values (R = -0.49; P = 0.001) and it was significantly lower in patients with a significant MIO than in those with no significant MIO (-18.3 ± 2 vs. -21.3 ± 2.7, P = 0.02). No significant difference was found for radial and circumferential strain in relation to the severity of MIO. Patients with impaired GLS (<-19.5%) had a significant higher risk of showing significant MIO (Odds-ratio-OR = 17; 95%). GLS is related with global T2* in TM patients. Moreover, GLS can identify TM patients with severe MIO detected by CMR.

Cardiovascular magnetic resonance native T2 and T2* quantitative values for cardiomyopathies and heart transplantations: a systematic review and meta-analysis

“…Lastly, for studies including iron overload patients most T 2 * measurements were performed in the intraventricular septum for reproducibility, because the lateral wall often contains dephasing artefacts. Nevertheless, some studies reported an average of the mid-ventricular SAx slice [87,115,119,134] or the entire myocardium [106,125,[127][128][129][130][131][132], which especially on 3 T [127] could lead to some unrealistic T 2 * values due to aforementioned artefacts.…”

Cardiac T2* mapping: Techniques and clinical applications

“…It has been recommended to use midventricular septum as a comparatively artifact‐free region to measure iron overload 31 . The postmortem finding showed that iron distribution is heterogeneous in the myocardium, as reported using the global longitudinal strain method, 43 and was confirmed by the T 2 * measurements in global myocardium 19–21,25,27,41,43,45,49,57–59 . Different iron overload patterns in different myocardial segments beyond the influence of susceptibility artifact were observed.…”

“…4). 25,43,46,57 Iron distribution identification in postmortem heart samples with severe iron overload revealed higher iron concentration in the epicardial than in the endocardial region 10,11,13 . It has been recommended to use midventricular septum as a comparatively artifact‐free region to measure iron overload 31 .…”

“…A decrease of RV and LV stroke volume was found in patients with increased cardiac iron 59 . In beta‐thalassemia major patients with significant iron accumulation, echocardiography analysis showed a reduction of left atria (LA) peak positive strain, LA total strain, right atria (RA) peak positive strain, RA total strain, LV global longitudinal strain, and LV global circumferential strain 43,86 …”

Oxygenation‐sensitive cardiovascular magnetic resonance in hypertensive heart disease with left ventricular myocardial hypertrophy and non‐left ventricular myocardial hypertrophy: Insight from altered mechanics and cardiac BOLD imaging

“…[1][2][3] HTN induces myocardial inflammation, fibrosis, vascular and myocardial remodeling. 4,5 A paramagnetic effect can be observed by the iron deposits (e.g., intramyocardial hemorrhage of myocardial infarction, 6,7 iron overload of hemochromatosis and thalassemia, [8][9][10] and the net or relative increase of deoxygenated hemoglobin [compared with oxygenated hemoglobin] in the capillary blood, which ultimately shortens the T2* relaxation times, measured using BOLD (blood oxygen level dependent) MRI. 11,12 BOLD MRI can detect regional condition of myocardial oxygen supply and demand by means of paramagnetic properties.…”