Left ventricular wall motion abnormalities in transfusion-dependent thalassemia: A large cross-sectional cardiovascular magnetic resonance study.

We investigated the prevalence of left ventricular (LV) wall motion abnormalities (WMA) and their associations with demographic, clinical, and laboratory parameters, myocardial iron, cardiac function, fibrosis, and history of heart failure and arrhythmias in a large cohort of patients with transfusion-dependent thalassemia (TDT). We included 1154 TDT patients (52.9% female; 37.46 ± 10.67 years) enrolled in the Extension-Myocardial Iron Overload in Thalassemia project. The CMR protocol (1.5T) included cine imaging to assess LV size and function, gradient-echo T2* images for myocardial iron overload (MIO) assessment, and late gadolinium enhancement (LGE) images for detection of replacement myocardial fibrosis. LV WMA were evaluated by visual interpretation of cine images using the standardized 16-segment LV model. Fifty-five (4.8%) patients showed LV WMA, predominantly hypokinesia affecting septal segments. Compared with patients with normal LV motion, those with WMA were older, more frequently diabetic, and more often splenectomized. LV WMA were associated with a higher prevalence of myocardial iron overload and LGE, increased LV volumes and mass, and reduced ejection fraction and myocardial contraction fraction. The frequency of LV WMA was significantly higher in patients with a history of heart failure or supraventricular arrhythmias. In multivariate analysis, LV WMA remained an independent risk factor for supraventricular arrhythmias, even after adjustment for fibrosis and other risk factors. In TDT, LV WMA are uncommon but reflect regional myocardial dysfunction related to iron overload and fibrosis. Assessment of regional LV function by CMR may help identify patients at higher risk of cardiac complications.