Myocardial Iron overload In Thalassemia Major. how Early To Check?

It is still controversy in thalassemia major (TM) if Cardiovascular Magnetic Resonance (CMR) T2* screening should be initiated before the 10 years. To answer this question, we studied retrospectively the prevalence of cardiac iron and function and myocardial fibrosis by CMR in a consistent cohort of TM patients younger than 10 years.

From the 2171 patients enrolled in the MIOT (Myocardial Iron Overload in Thalassemia) network, we retrospectively selected the 35 TM patients aged less than 10 years who had undergone at least one MRI scan. Myocardial iron overload (MIO) was measured by T2* multislice multiecho technique. Biventricular function parameters were quantitatively evaluated in a standard way by cine images. To detect myocardial fibrosis, late gadolinium enhancement images were acquired.

Patients’ age ranged from 4.2 to 9.7 years. All MRI scans were performed without sedation. Nine patients (25.7%) showed no myocardial iron overload (MIO),22 patients (62.9%) showed an heterogeneous MIO with a T2* global value ≥ 20 ms; 2 patients (5.7%) showed an heterogeneous MIO and a T2* global value < 20 ms and 2 patients (5.7%) had a homogeneous MIO. No patients showed myocardial fibrosis.

Table 1 reports the data of the 4 patients (3 males and 1 female) with significant myocardial iron overload (global heart T2* < 20 ms). The youngest was 6 years old, all showed no heart dysfunction and in all the iron transfused was less than 35 g.

The first cardiac T2* assessment should be performed as early as possible without sedation and it is mandatory whenever poor compliance is suspected or if chelation has been started late. The use of the contrast medium to detect myocardial fibrosis can be postponed until after 10 years of age. A more sensitive segmental approach to detected heart iron should be considered. Therapy can be modified on the basis of the MRI results and serious organ damage can be prevented.

No relevant conflicts of interest to declare.