Developments in the management of Chagas cardiomyopathy

Abstract

Over 100 years have elapsed since the discovery of Chagas disease and there is still much to learn regarding pathogenesis and treatment. Although there are antiparasitic drugs available, such as benznidazole and nifurtimox, they are not totally reliable and often toxic. A recently released negative clinical trial with benznidazole in patients with chronic Chagas cardiomyopathy further reinforces the concerns regarding its effectiveness. New drugs and new delivery systems, including those based on nanotechnology, are being sought. Although vaccine development is still in its infancy, the reality of a therapeutic vaccine remains a challenge. New ECG methods may help to recognize patients prone to developing malignant ventricular arrhythmias. The management of heart failure, stroke and arrhythmias also remains a challenge. Although animal experiments have suggested that stem cell based therapy may be therapeutic in the management of heart failure in Chagas cardiomyopathy, clinical trials have not been promising.

Keywords: Arrhythmias; Chagas cardiomyopathy; Chagas disease; heart failure; myocardial fibrosis; nanotechnology; oxidative stress; stem cell therapy; vaccine development.

Figure 1. Heart of a patient who died of Chagas cardiomyopathy

There is cardiac enlargement and a prominent apical aneurysm (arrow). Courtesy of Armed Forces Institute of Pathology, United States.

Figure 2

This is a 12-lead ECG of a patient with severe Chagas cardiomyopathy, showing right bundle branch block and left anterior hemiblock.

Figure 3. Histopathology of the heart from a patient who died while awaiting cardiac transplant

(A) H&E showing bands of fibrous tissue. (B) Trichrome staining showing the bands of fibrous tissue. Reproduced from Johndrow et al. (2014) [51] Microbes and Infection, with permission of Elsevier.

Figure 4. Echocardiography of a patient with chronic chagas cardiomyopathy

(A) Two-dimensional echocardiography at the apical four-chamber view of the left ventricle demonstrating a dilated apical aneurysm. There is a distinct limit between the normal contractile myocardium and the dyskinetic apex (arrow) with bulging motion during systole. (B) Two-chamber apical view showing an apical thrombus (arrow). There is a mass attached to the left ventricular apical aneurysm with a margin distinct from the underlying wall, which is dyskinetic. LA: Left atrium, LV: Left ventricle; RA Right atrium; RV Right ventricle.