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 Introduction: Myocardial iron overload is a well established cause of heart failure in a number of haematological disorders and is the leading cause of death in β-thalassaemia major (TM). Once overt heart failure develops prognosis is very poor and it would therefore be desirable to identify patients at risk, prior to the development of symptomatic heart failure. Myocardial iron can now be rapidly and reproducibly assessed using a validated cardiac magnetic resonance (CMR) T2* technique. Left ventricular ejection fraction has been demonstrated to relate to myocardial T2* (normal >20ms), and accordingly iron overloaded patients with symptomatic heart failure are likely to have a low T2* but there are no reports of the myocardial T2* level in newly presenting patients with heart failure and the threshold for increased risk is also unknown. Purpose: To establish the distribution of myocardial T2* values in patients presenting with symptomatic heart failure secondary to iron overload. Methods: Database records of CMR T2* assessments over a 5 year period were reviewed to identify iron overloaded patients presenting with heart failure. Results: 28 patients (median age 29y, 11–79) with iron overload and documented heart failure were identified. 22 patients had thalassaemia major, 3 hereditary haemochromatosis, and 3 had miscellaneous transfusion dependent anaemias. The mean myocardial T2* in all groups was 6.8+/− 2.2ms reflecting severe iron loading by clinical criteria. See figure 1. Myocardial T2* values were similar between sub-groups as follows: TM patients 6.7+/− 2.4ms, haemochromatosis 7.7ms (6.7–7.4ms), miscellaneous 6.8ms (4.8–9.1ms). Conclusion: In this database review, the patients developing heart failure secondary to iron overload all had abnormal myocardial T2*, and overall 89% of heart failure patients had values less than 10ms, which reflects severe myocardial iron loading. This data suggests a myocardial T2* <10ms should be considered a threshold for risk of heart failure (with its attendant high mortality) and such patients should be treated aggressively with increased iron chelation. It also suggests that clinical heart failure occurs nearly exclusively in patients with severe myocardial iron loading. Distribution of myocardial T2+ values in symptomatic heart failure (n=28) Distribution of myocardial T2+ values in symptomatic heart failure (n=28)

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Multi-Centre Validation of the Cardiovascular Magnetic Resonance Multi Breath-Hold T2* Technique for Myocardial Iron Quantification in Thalassaemia Major.

Blood ◽

10.1182/blood.v106.11.3828.3828 ◽

2005 ◽

Vol 106 (11) ◽

pp. 3828-3828

Author(s):

Mark A. Tanner ◽

Taigang He ◽

Mark A. Westwood ◽

Renzo Galanello ◽

Gildo Matta ◽

...

Keyword(s):

Magnetic Resonance ◽

Iron Overload ◽

Breath Hold ◽

Myocardial Iron ◽

Thalassaemia Major ◽

Non Invasive ◽

Cardiac Siderosis ◽

Iron Quantification ◽

Siemens Sonata ◽

Roll Out

Abstract Introduction: Beta thalassaemia major (TM) is a hereditary anaemia affecting 60 000 births worldwide each year. Survival is dependent upon lifelong blood transfusions resulting in iron overload. Cardiac siderosis can result in a cardiomyopathy which is the leading cause of death in TM. The validated cardiac magnetic resonance (CMR) T2* technique allows non-invasive and reproducible quantification of myocardial iron. Assessment of myocardial iron loading is essential in determining appropriate chelation therapy. This technique has the potential to become the new gold standard in the assessment of cardiac siderosis but is currently available at only a few sites worldwide. For maximal healthcare benefit its inter-scanner reproducibility must be demonstrated before being widely disseminated. Objective: To demonstrate that CMR T2* quantification of myocardial iron can be reproducibly transferred to MR scanners of different manufacturers in different centres. This project was sponsored by the Thalassemia International Federation. Methods: The previously described multi breath-hold gradient echo T2* technique was installed on MR scanners (all 1.5Tesla) at 6 different centres. Scanner details were as follows: Site 1, Phillips Intera (Turin, Italy), Site 2, Siemens Sonata (Philadelphia, USA), Site 3 GE Signa (Limassol, Cyprus) Site 4, Phillips Intera (Nicosia, Cyprus), Site 5, GE Signa (Cagliari, Sardinia) and Philips Intera (Genova, Italy). 34 patients (mean age 30+/− 5.7years) were scanned in total. All patients were subsequently re-scanned at the standardization centre in London, UK (Siemens Sonata, 1.5T) within 31 days of their original scan. Results: The T2* sequence was successfully installed on all 6 scanners. Myocardial T2* values ranged from 3.6ms to 51ms (14.2 +/− 11ms). The overall inter-scanner reproducibility (SD/mean) was 5.3% (figure 1). The mean difference between T2* values at the standardization centre and visited sites was 0.32ms. Conclusion: We have demonstrated that the multi breath-hold T2* technique for the quantification of myocardial iron can be reproducibly transferred to 1.5T MR scanners at different sites and of different manufacturers. There is therefore real potential to roll out this technique worldwide to facilitate maximal healthcare impact in the management of patients with iron overload conditions such as thalassaemia. Figure Figure

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Myocardial iron overload in thalassaemia major. How early to check?

British Journal of Haematology ◽

10.1111/bjh.12643 ◽

2014 ◽

Vol 164 (4) ◽

pp. 579-585 ◽

Cited By ~ 33

Author(s):

Caterina Borgna-Pignatti ◽

Antonella Meloni ◽

Giulia Guerrini ◽

Letizia Gulino ◽

Aldo Filosa ◽

...

Keyword(s):

Iron Overload ◽

Myocardial Iron ◽

Thalassaemia Major

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Restrictive lung disease in β-thalassemia major is associated with myocardial iron overload

10.22541/au.163624223.30019388/v1 ◽

2021 ◽

Author(s):

Kate Chan ◽

Chun Ting Au ◽

Alex Wing Kwan Leung ◽

Albert Li ◽

Chi-kong Li ◽

...

Keyword(s):

Relaxation Time ◽

Lung Function ◽

Iron Overload ◽

Myocardial Iron ◽

Pulmonary Dysfunction ◽

Thalassaemia Major ◽

T2 Relaxation Time ◽

T2 Relaxation ◽

Restrictive Lung Disease

Background: Pulmonary dysfunction has been reported in patients with β-thalassaemia major but data are conflicting and the association with iron overload remains unclear. Objectives: To determine the pattern of pulmonary dysfunction in patients with β-thalassaemia major and their associations with iron overload. Methods: Subjects with β-thalassaemia major were recruited for lung function assessment. Serum ferritin and magnetic resonance imaging (MRI) measurements of iron status of the myocardium and the liver were used as surrogate indexes of body iron content. A subgroup of this cohort provided data on the longitudinal progress of their lung function. Results: One hundred and one patients were recruited with a mean age of 25.1 years (SD 7.9 years). Thirty-eight (38%) and five (5%) had restrictive and obstructive lung function deficits, respectively. There was a significant correlation between MRI myocardial T2* relaxation time and forced vital capacity (r=0.291, p=0.048). Higher MRI cardiac T2* relaxation time was associated with lower risk of having restrictive lung function deficit (Odds ratio (OR): 0.94; 95% CI: 0.89-0.99; p=0.023) after adjusting for age, gender and BMI. Twenty-three subjects underwent lung function reassessment with a mean follow-up duration of 13 years. Overall, they did not demonstrate significant changes in pulmonary function over time, 3 patients who had normal lung function at baseline developed restrictive abnormality at follow-up. Conclusions: Restrictive lung disease is prevalent in patients with β-thalassaemia major, and the severity correlates with myocardial iron overload. Monitoring of lung function in this group of patients is important, particularly for those with iron overload.

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