Myocardial involvement in Chagas disease: insights from cardiac magnetic resonance

Background: Chagas' disease is becoming a public health problem in Europe because of migratory movements. Cardiac magnetic resonance (CMR) has emerged as a non-invasive tool to assess cardiac tissue characteristics. There is scarce data available on CMR in patients with Chagas' disease.

Objective: To describe CMR findings in patients with Chagas' disease living in a non-endemic area focusing on differentiation from other cardiomyopathies and relation with clinical status.

Methods and results: Sixty-seven Chagas' disease patients divided into 3 groups-group 1 (indeterminate form: positive serology without ECG or 2D-echocardiographic abnormalities; N = 27), group 2 (ECG abnormalities of Chagas' disease but normal 2D-echocardiography; N = 19), and group 3 (regional wall motion abnormalities, LV end-diastolic diameter >55 mm or LV ejection fraction <50% on echocardiography; N = 21)--were studied. The presence of wall motion abnormalities and delayed enhancement (DE) by CMR was more frequent in the inferolateral and apical segments. DE distribution in the myocardial wall was heterogeneous (subendocardial 26.8%, midwall 14.0%, subepicardial 22.6%, and transmural 36.0% of total segments with DE) and related to larger cardiac chambers and worse systolic function.

Conclusion: Pattern of DE in Chagas' disease may mimic that of both ischemic and nonischemic cardiomyopathies, with especial predilection for the apical and inferolateral segments of the left ventricle. These findings support that myocardial involvement in chronic Chagas' cardiomyopathy (CCC) may be due to both microvascular disturbances and chronic myocarditis and may favor CCC in the differential diagnosis of patients with compatible epidemiological history and heart failure of uncertain etiology.