Normalized left ventricular volumes and function in thalassemia major patients with normal myocardial iron

Abstract

Purpose:To determine the reference range in thalassemia major (TM) for left ventricular (LV) function. Materials and Methods:We used cardiovascular magnetic resonance (CMR) to measure heart volumes and function in 81 TM patients with normal myocardial T2* measurements (T2* Ͼ 20 msec) and by inference without excess myocardial iron. Forty age-and gender-matched healthy controls were also studied. Results:Resting LV volumes and function normalized to body surface area differed significantly between TM patients and controls. The lower limit and the mean for ejection fraction (EF) were higher in TM patients (males 59 vs. 55%, mean 71% vs. 65%; females 63 vs. 59%, mean 71% vs. 67%; both P Ͻ 0.001). The upper limit and mean for enddiastolic volume index were higher in TM patients (males 152 vs. 105 mL/m 2 , mean 97 vs. 84 mL/m 2 ; females 121 vs. 99 mL/m 2 , mean 87 vs. 79 mL/m 2 ; both P Ͻ 0.05). In TM patients the cardiac index (P Ͻ 0.001) was increased. Conclusion:At rest, TM patients with a normal myocardial T2* have different "normal" values for LV volume and function parameters compared to controls, and this has the potential to lead to a misdiagnosis of cardiomyopathy. We present new reference "normal" ranges in TM to alleviate this problem.

The relationship between myocardial t2* and left ventricular volumetric and functional parameters in thalassemia major patients

“…TM patients have greater left ventricular ejection fractions than controls (16). Thalassemia patients have impaired left ventricular function at higher values of LVEF than previously thought (9,25).…”

“…The body habitus may be below aver age in TM patients, so all parameters were indexed to the body surface area. The normal ranges for LV volumes and function were obtained from the published data for TM patients with normal myocardial iron (16). The lower limit of normal for EF was considered to be 59%, and normal ranges for the LV end-systolic volume index (LVESVi) was 13-34 mL/m² and that for the LV end-diastolic volume index (LVEDVi) was 45-152 mL/m².…”

Cardiac iron and cardiac disease in males and females with transfusion-dependent thalassemia major: a T2* magnetic resonance imaging study

“…15 In order to avoid bias due to the use of different software, we defined our limit of normal for LVEF. Among 776 thalassemia major patients present in the MIOT database who had undergone at least one cardiac MRI examination at the time of the study, we selected 93 patients with no history of cardiac disease, a normal electrocardiogram, no known risk factors, and T2* values greater 20 ms in all cardiac segments.…”

Iron overload and iron chelation therapy in patients with myelodysplastic syndrome treated by allogeneic stem‐cell transplantation: Report from the working conference on iron chelation of the Gruppo Italiano Trapianto di Midollo Osseo

“…Estimation of myocardial iron by MRI has become increasingly available but requires expertise in use and standardization [45]. The T2* value in cardiac tissue shorten as the iron concentration increases, and, in thalassemia, a T2* value <20 ms (implying myocardial iron overload) has been associated with a higher risk of decreased left ventricular ejection fraction [46]. MRI T2* has been used to study both liver and myocardial iron loading in patients with MDS.…”

“…In the thalassemia experience, serum ferritin and the transferrin saturation slowly return to normal only in patients with a very low iron burden before transplantation [15]. Persistence of tissue iron overload after allo-SCT can cause significant morbidity and mortality, as observed in thalassemia patients [46,54]. To remove excess iron appears to be particularly relevant in patients affected by HCV infection because of the well-known synergic effect of these two conditions [16].…”