ABSTRACT
Cardiomyopathy is a major cause of death in Chagas disease and early detection of cardiac involvement is essential. Myocardial strain is a reliable technique for assessment of subtle left ventricular (LV) contractility alterations. This study assessed LV global longitudinal strain (GLS) in a large Chagas disease population living in remote areas. Between 2015 and 2016, Chagas disease patients were selected in the northern of the Minas Gerais state. All patients underwent T. cruzi antibodies tests and those who had positive tests were included. A resting 12-lead ECG was recorded and classified using the Minnesota Code criteria. Echocardiography was performed at public health primary care units and speckle-tracking strain was analyzed offline. LV dysfunction was defined as ejection fraction (LVEF < 50%) and reduced GLS was defined as < 16% (absolute value). A total of 1387 patients were included, mean age of 60.0 ± 12.5 years, 68% were women, and 14% had LV dysfunction. Among patients with normal LVEF, 59% had impaired LV GLS. Overall, patients with impaired GLS were older, had more comorbidities and ECG abnormalities than those with normal GLS. The independent factors associated with reduced GLS were ST-T abnormalities (OR 1.954; 95% CI 1.027-3.718), QRS duration (OR 1.009; 95% CI 1.002-1.016), LVEF (OR 0.947; 95% CI 0.923-0.972), and E/e' ratio (OR 1.059; 95% CI 1.009-1.112). In a cohort of Chagas disease from endemic areas, impaired LV GLS was detected in a significant proportion of patients, despite normal ECG and preserved LVEF. The main determinants of reduced LV GLS were ST-T abnormalities, QRS duration, LVEF and E/e' ratio, adjusting for demographical and clinical data.
