Magnetic resonance evaluation of liver and myocardial iron deposition in thalassemia intermedia and b-thalassemia major.

INTRODUCTION

b-Thalassemia major (TM) and thalassemia intermedia (TI) are forms of inherited hemoglobinopathies. Our aim was to evaluate a population of asymptomatic TM and TI patients using cardiovascular magnetic resonance (CMR). We hypothesized that the TI group could be differentiated from the TM group based on T2*. We also hypothesized that the TI group would demonstrate significantly higher cardiac output compared to the TM group.

PATIENTS AND METHODS

Twenty-one consecutive TI patients aged 23(19-25) years, 21 TM patients and 21 age and sex matched controls were studied. Evaluation of heart, liver T2* relaxation time and right and left ventricular parameters was performed using a 1.5 T system.

RESULTS

Myocardial and liver T2* values were significantly higher in TI patients compared to TM (34.35 +/- 2.36 vs 15.77 +/- 3.53 m, P < 0.001 and 5.12 +/- 6.52 vs 1.36 +/- 0.53 ms, P < 0.001, respectively). Controls had myocardial T2* 35.07 +/- 4.52 ms (similar to TI patients, but significantly increased compared to TM patients, P < 0.001) and liver T2* 26.28 +/- 2.37 ms (significantly increased compared to both TI and TM patients, P < 0.001). Left ventricular end-diastolic (LVEDV), end-systolic (LVESV) volumes and left ventricular ejection fraction (LVEF) were higher in TI patients compared to TM (P < 0.001). Stroke volume (LVSV), cardiac output (LVCO) and cardiac index (LVCI) were similarly increased in TI patients compared to TM (P < 0.001). Right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV) and right ventricular ejection fraction (RVEF) were higher in TI patients compared to TM (P < 0.001).

CONCLUSIONS

Although in TM iron plays a crucial role in the evolution of the disease, in TI the high output cardiac state seems to be the most prominent finding.