How Early Can Myocardial Iron Overload Occur in Beta Thalassemia Major?

Gaohui Yang,Weijia Yang,Shaohong Tan,Taigang He,Xinhua Zhang,Liling Long,Hongfei Pan,Xingjiang Long,Lisa Anderson,Yongrong Lai,Peng Peng,Rongrong Liu,Xiaolei Xu

doi:10.1371/journal.pone.0085379

Abstract

BackgroundMyocardial siderosis is the most common cause of death in patients with beta thalassemia major(TM). This study aimed at investigating the occurrence, prevalence and severity of cardiac iron overload in a young Chinese population with beta TM.Methods and ResultsWe analyzed T2* cardiac magnetic resonance (CMR), left ventricular ejection fraction (LVEF) and serum ferritin (SF) in 201 beta TM patients. The median age was 9 years old. Patients received an average of 13 units of blood per year. The median SF level was 4536 ng/ml and 165 patients (82.1%) had SF>2500 ng/ml. Myocardial iron overload was detected in 68 patients (33.8%) and severe myocardial iron overload was detected in 26 patients (12.6%). Twenty-two patients ≤10 years old had myocardial iron overload, three of whom were only 6 years old. No myocardial iron overload was detected under the age of 6 years. Median LVEF was 64% (measured by CMR in 175 patients). Five of 6 patients with a LVEF<56% and 8 of 10 patients with cardiac disease had myocardial iron overload.ConclusionsThe TM patients under follow-up at this regional centre in China patients are younger than other reported cohorts, more poorly-chelated, and have a high burden of iron overload. Myocardial siderosis occurred in patients younger than previously reported, and was strongly associated with impaired LVEF and cardiac disease. For such poorly-chelated TM patients, our data shows that the first assessment of cardiac T2* should be performed as early as 6 years old.

Highlights

Myocardial siderosis remains the most common cause of death in patients with beta thalassemia major (TM) [1]
Myocardial siderosis occurred in patients younger than previously reported, and was strongly associated with impaired left ventricular ejection fraction (LVEF) and cardiac disease
For such poorly-chelated TM patients, our data shows that the first assessment of cardiac T2* should be performed as early as 6 years old

Summary

Introduction

Myocardial siderosis remains the most common cause of death in patients with beta thalassemia major (TM) [1] In affluent countries such as the UK, there has been a dramatic improvement in survival since the introduction of cardiovascular magnetic resonance(CMR) for assessment of myocardial iron [2], but iron induced cardiomyopathy still accounts for the majority of all deaths [3]. For poorly-chelated patients, there is limited data on when the myocardial siderosis occurs and when the CMR T2* screening should be initiated To answer these questions, we designed this study to determine the age when cardiac iron overload occurs and the prevalence of abnormal cardiac MRI T2* and myocardial function on a large young TM population in mainland China. This study aimed at investigating the occurrence, prevalence and severity of cardiac iron overload in a young Chinese population with beta TM

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Conclusion