Myocardial native T1 mapping and cardiac outcomes in thalassemia major

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): The E-MIOT project receives “no-profit support” from industrial sponsorships (Chiesi Farmaceutici S.p.A. and ApoPharma Inc. and Bayer). Background. The T2* cardiovascular magnetic resonance (CMR) is the gold standard for the non invasive detection of myocardial iron overload (MIO). The native myocardial T1 mapping has been proposed as a complementary tool, thanks to its higher sensitivity in presence of small amounts of iron, but no data are available in literature about its clinical impact. Objective To explore the clinical impact of T1 mapping for detecting cardiac complications in thalassemia major (TM). Methods. We considered 146 TM patients (87 females, 38.7 ± 11.1 years) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network. Three parallel short-axis slices of the left ventricle (LV) were acquired with the Modified Look-Locker Inversion recovery (MOLLI) sequence. The native T1 values in all 16 myocardial segments were obtained and the global value was the mean. Results. Twenty-one patients had an history of cardiac complications: 11 heart failure, 8 arrhythmias (7 supraventricular and 1 ventricular), and 2 pulmonary hyperthension. Patients with cardiac complications had significantly lower global heart T1 values (879.3 ± 121.9 ms vs 963.2 ± 98.5 ms; P < 0.0001) (Figure) but comparable T2* values (33.32 ± 11.66 ms vs 37.17 ± 9.15 ms; P = 0.116). Cardiac complications were more frequent in the group of patients with reduced global heart T1 value (<928 ms for males and <989 ms for females) compared to the group with normal global heart T1 value (71.4% vs 39.5%; P = 0.009). Odds ratio (OR) for cardiac complications was 3.8 (95%CI = 1.3-10.9) for patients with reduced global heart T1 value versus patients with normal global heart T1 value. Conclusion We found out a significant association between decreased native global heart T1 values and a history of cardiac complications, suggesting that an early detection of myocardial iron burden by native T1 can support the clinicians in modifing chelation therapy earlier. Abstract Figure.