The correlation between cardiac magnetic resonance T2* and left ventricular global longitudinal strain in people with β-thalassemia.

Abstract

Heart failure is the biggest cause of mortality and morbidity in people with thalassemia, and iron deposition in cardiac tissue impairs cardiovascular function. Therefore, early detection of cardiac involvement is important to improve the prognosis in these individuals. Two- and three-dimensional echocardiography was performed to evaluate left ventricular ejection fraction (LVEF), left ventricular volumes and diameters, and global longitudinal strain (GLS) in 130 individuals with β-thalassemia using the speckle tracking method. Magnetic resonance imaging (MRI) was carried out on both the heart and liver. The participants were divided into 2 groups based on cardiac T2* values (normal and abnormal cardiac iron load), and the correlation between cardiac T2* MRI and GLS was evaluated. The statistical analysis showed a significant correlation between cardiac T2* MRI and left ventricular global longitudinal strain. There was a significant difference in global longitudinal strain (P<.0001), liver MRI T2*( P<.0001), and left ventricular ejection fraction (P<.001) between the 2 groups. The optimal cutoff value for GLS was -18.5% with sensitivity and specificity 73.0% and 63.0%, respectively (postitive predictive value=50%, negative predictive value=82.3%, AUC=0.742, std. error=0.046) which predicts T2* value of <20ms, according to cardiac MRI. The participants with cardiac iron overload had a lower GLS than those without one. This suggests that GLS may be a useful method to predict myocardial iron overload particularly in β-thalassemia patients with subclinical cardiac involvement.