Etiological treatment of chronic Chagas disease: neglected 'evidence' by evidence-based medicine

Cardiac involvement in African and American trypanosomiasis

American trypanosomiasis (Chagas disease) and human African trypanosomiasis (HAT; sleeping sickness) are both caused by single-celled flagellates that are transmitted by arthropods. Cardiac problems are the main cause of morbidity in chronic Chagas disease, but neurological problems dominate in HAT. Physicians need to be aware of Chagas disease and HAT in patients living in or returning from endemic regions, even if they left those regions long ago. Chagas heart disease has to be taken into account in the differential diagnosis of cardiomyopathy, primarily in patients with pathological electrocardiographic (ECG) findings, such as right bundle branch block or left anterior hemiblock, with segmental wall motion abnormalities or aneurysms on echocardiography, and in young patients with stroke in the absence of arterial hypertension. In HAT patients, cardiac involvement as seen by ECG alterations, such as repolarisation changes and low voltage, is frequent. HAT cardiopathy in general is benign and does not cause relevant congestive heart failure and subsides with treatment. We review the differences between the American and African trypanosomiasis with the main focus on the heart.

Chemotherapy of chronic indeterminate Chagas disease: a novel approach to treatment

Treatment of Chagas disease is a controversial issue because the available drugs are highly toxic. Clomipramine is a tricyclic antidepressant drug that inhibits Trypanosoma cruzi's trypanothione reductase, provoking the death of the parasite and preventing the cardiac damage when used for the treatment of acutely infected mice. Here, we studied the effectiveness of clomipramine (5 mg/kg/day for one month) as chemotherapy for T. cruzi-infected mice in the chronic indeterminate stage of the infection. The animals were analyzed in the cardiac chronic phase. Survival of treated animals was 84% while for the untreated ones was 40%; most of the animals presented electrocardiographic abnormalities. Affinity and density of cardiac beta receptors from infected and treated mice were similar to those in the indeterminate phase, showing that clomipramine treatment stopped the increment of functional alterations provoked by the infection, while untreated mice presented affinity and density significantly diminished. Hearts from infected and untreated mice in the chronic stage presented mononuclear cells, necrosis and fiber dissolution while hearts from treated animals showed only isolated inflammatory infiltrates. Present results demonstrate that clomipramine used in the chronic indeterminate phase of the T. cruzi infection modified the natural evolution of the chagasic cardiopathy.