Cardiac T2* magnetic resonance for prediction of cardiac complications in thalassemia major
© Kirk et al; licensee BioMed Central Ltd. 2009
Published: 28 January 2009
Myocardial siderosis is the main cause of morbidity and mortality in thalassaemia major. In the United Kingdom approximately 50% of patients die before reaching 35 years. The cardiomyopathy is reversible if chelation is commenced early but diagnosis is often delayed due to the late onset of symptoms. T2* CMR can now assess cardiac iron directly and this has profound implications for clinical management of iron overload and the assessment of chelation regimes.
Left ventricular ejection fraction falls with increasing myocardial iron (reduced myocardial T2*; normal value >20 ms), and accordingly iron overloaded patients with symptomatic heart failure have a low T2*. Although data is available on the level of T2* in patients developing heart failure there is no published data on the incidence of heart failure and arrhythmia in patients during follow-up according to baseline myocardial T2*. The aim of this study therefore was to establish the risk of cardiac complications in patients with cardiac siderosis as measured by T2*.
A prospective database containing clinical data and T2* values on 652 thalassaemia major patients (1442 scans) was maintained over a 6 year period with 1,285 patient years of prospective follow-up. Of these patients, 319 were male and 333 female with a mean age at time of first scan of 27.1 ± 9.6 years. The mean number of blood units transfused per year per patient was 32.6 ± 11.5.
At 1 year of follow-up, there were 84 episodes of heart failure and 100 episodes of arrhythmia. There were 4 deaths, with 3 patients dying from sepsis following bone marrow transplant and 1 patient dying following an episode of ventricular tachycardia.
These data provide strong evidence that a myocardial T2* <10 ms predicts a high risk of developing heart failure. It is clear that these patients should be aggressively chelated to reduce their high morbidity and mortality from cardiac siderosis.
This article is published under license to BioMed Central Ltd.