A recent study validated the use of cardiac T2* magnetic resonance imaging (MRI) for evaluating cardiac siderosis, or iron deposition, in patients with thalassemia major. The study’s findings were published in the journal Tomography.
Patients with thalassemia major who require blood transfusions are at risk of iron overload, which can lead to life-threatening complications, such as heart failure. According to the researchers, prior studies have aimed to quantify iron deposition, with some showing evidence that cardiac T2* MRI may have utility in estimation of iron levels in patients with thalassemia major. The researchers indicated this may be useful for guiding iron chelation therapy.
In this retrospective cohort study, 119 patients with thalassemia major were evaluated who had been seen at the Adult Hematology Clinic at Khon Kaen University in Khon Kaen, Thailand. Patients underwent assessments of cardiac T2* MRI measurement, serum ferritin levels, liver iron concentration, and left ventricular ejection fraction. Results from evaluations at baseline and 1, 3, and 5 years were reported.
Degree of cardiac siderosis was categorized as normal (T2* >25 milliseconds [ms]), marginal (T2* 20-25 ms), mild to moderate (T2* 10-20 ms), or severe (T2* ≤10 ms). Iron chelation therapy was intensified in patients who had T2* ≤25 ms.
Cardiac siderosis was detected at baseline in 17.6% of patients, based on status of T2* MRI being ≤25 ms. The researchers found no significant correlations between cardiac T2* MRI and serum ferritin levels (P =.39), liver iron concentration (P =.54), or left ventricular ejection fraction (P =.09).
Over time, significant improvements were seen in cardiac siderosis as determined by cardiac T2* MRI at follow-ups. Patients with severe cardiac siderosis at baseline had an initial mean cardiac T2* of 8.5 + 1.5 ms, and at 5-year follow-up it was 33.9 + 1.9 ms.
Significant increases in cardiac T2* were also seen over time for other patients who showed cardiac siderosis at baseline. Those categorized as having marginal cardiac siderosis showed a significant improvement by the 1-year follow-up, and those with mild to moderate cardiac siderosis at baseline showed a significant improvement at the 3-year follow-up. Patients who were considered to have normal status at baseline showed no significant difference in cardiac T2* signal over the course of the study.
“The study validates the current practice of using the cardiac T2* MRI to adjust iron chelation therapy in patients with cardiac siderosis by revealing that patients’ cardiac T2* MRI improved over time,” the researchers concluded in their report.
Chaosuwannakit N, Makarawate P, Wanitpongpun C. The importance of cardiac T2* magnetic resonance imaging for monitoring cardiac siderosis in thalassemia major patients. Tomography. 2021;7(2):130-138. doi:10.3390/tomography7020012