Comparison of effects of different long-term iron-chelation regimens on myocardial and hepatic iron concentrations assessed with T2* magnetic resonance imaging in patients with β-thalassemia major

Abstract

The aim of this study was to compare the effect of different long-term chelation regimens on heart and liver iron stores with the use of T2* magnetic resonance imaging (MRI) in patients with transfusion-dependent beta-thalassemia major. Sixty-four patients (28 men, 36 women; mean age, 26.49 +/- 5.8 years) were enrolled in the study. The 3 groups were based on the chelation therapy received. The first group (19 patients) received deferiprone (DFP) (75 mg/kg per day orally), the second group (23 patients) received deferoxamine (DFO) (30-50 mg/kg per day subcutaneously at least 5 times/week), and the third group (22 patients) received a combination of DFO (30-50 mg/kg per day, 2-3 days/week) and DFP (75 mg/kg per day, 7 days/week). MRI scans were acquired with an imager equipped with a 1.5 T magnet, and the data included myocardial and hepatic iron measurements obtained by means of T2*, and ventricular volumes and ejection fractions obtained with standard cardiovascular MRI techniques. The results revealed that the DFP and the combined groups had significantly less myocardial iron than the DFO group (mean myocardial T2*, 35.77 +/- 18.3 milliseconds and 38.05 +/- 15.3 milliseconds versus 23.77 +/- 13 milliseconds [P = .02, and P = .001], respectively). On the contrary, the DFP group had a significantly higher hepatic iron content than the DFO and combined groups (mean hepatic T2*, 3.29 +/- 2.5 milliseconds versus 8.16 +/- 8.4 milliseconds and 11.3 +/- 10.9 milliseconds [P = .014, and P = .003], respectively). No correlation was observed between myocardial T2* and hepatic T2* values (r = -0.043; P = .37). Myocardial T2* values were inversely correlated with age (r = -0.249; P = .024) and positively correlated with both left and right ventricular ejection fractions (r = 0.33 [P = .004], and r = 0.279 [P = .014], respectively). Finally, liver T2* was strongly and inversely correlated with serum ferritin concentration (r = -0.465; P = .001). In conclusion, combined chelation therapy seems to sum the beneficial effects of DFO and DFP with respect to hepatic and myocardial iron. Because myocardial iron is not related to measurements of serum ferritin or hepatic T2*, important decisions on clinical management relating to cardiac risk should not rely on these conventional parameters. Thus, the use of MRI for assessing myocardial iron should be adopted in the routine clinical management of patients with beta-thalassemia major.

Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload

“…Group A patients had significant higher serum ferritin levels compared with the patients with normal single ROI T2* value (Group B). In fact, as widely reported in the literature, liver T2* is strongly and inversely correlated with serum ferritin concentration (25,26). Moreover, Group A was younger and, consequently, had undergone chelation therapy for a shorter time.…”

MRI evaluation of hepatic and cardiac iron burden in pediatric thalassemia major patients: spectrum of findings by T2*

“…In agreement with our results, Anderson [12] reported that a marked discordance was observed between hepatic and cardiac iron concentration. Also Di Tucci et al [28], Tanner et al [29], Perifanis et al [30], and Wood et al [17] reported that no correlation was found among liver T2*, cardiac T2*, and iron concentration levels.…”

Causes for Hospitalization and Death in Iranian Patients with β-Thalassemia Major

“…Adequate chelation therapy usually prevents the development of liver fibrosis in hepatitis C-free BTM patients and reduces the risk of developing severe fibrosis in thalassemics with chronic hepatitis C [14]. Patients who undergo combination therapy with deferiprone and deferoxamine have a significant reduction in hepatic and myocardial iron overload when compared with deferoxamine monotherapy [15]. Liver biopsy could be substituted by noninvasive methods; hepcidin measurements may allow a more accurate assessment of the degree of iron overload and the [16]; and R2 * -MRI measurements are also suggested for predicting hepatic iron content [17].…”