Detection of Early Cardiac Dysfunction in Patients with Beta Thalassemia by Tissue Doppler Echocardiography

Abstract

In this study we tried to evaluate the prognostic significance of several echocardiographic parameters on the occurrence of heart failure or arrhythmias in patients with beta thalassemia. We investigated possible differences in myocardial function between a population of 37 asymptomatic patients with beta thalassemia and 25 age-matched healthy controls, all of whom underwent an echocardiographic study, including tissue Doppler imaging (TDI), moreover plasmatic levels of N-terminal pro-BNP (NT-pro BNP) were measured in all patients. We followed the patients for 22 ± 8 months to evaluate adverse cardiac events. Conventional echocardiographic parameters of left ventricle were comparable in both groups. Whereas TDI peak systolic velocity (Sm) and diastolic parameter (E/Em ratio) were significantly abnormal in patients with thalassemia. Moreover eleven adverse cardiac events were observed during follow-up. Baseline systolic velocity (Sm) <7.9 cm/s was significantly associated with cardiac complications (P < 0.05). We also demonstrated that systolic velocity is inversely related to NT-proBNP plasmatic levels (P < 0.001). Our study suggests that mitral annular systolic velocity <7.9 cm/s is associated to the onset of adverse cardiac events.