• Chagas
• disease
• stroke

We read with interest the paper by Carod-Artal et al¹ that showed the relevance of Chagas’ disease as a stroke risk factor in patients of South American origin. They also confirmed a textbook view² (not hitherto demonstrated) that cardioembolism is the main cause of stroke in Chagas’ disease, in 52% of cases. This reflects in part the underlying chagasic cardiomyopathy, characterised by congestive heart failure and arrhythmias, present in 46% of chagasic patients as compared with 25% of non-chagasic patients.

Despite the lack of comparison of stroke characteristics between both groups, one very interesting finding was the significant percentage of chagasic patients who developed stroke without any known vascular risk factors or cardiopathy. As the authors stated, undetected cardiovascular disease could account for at least part of this finding. The indeterminate form of the disease is defined by the presence of infection confirmed by serological tests, in the absence of symptoms or of electrocardiographic or radiological abnormalities. Twenty five % of subjects with the indeterminate form of the disease may present significant structural and/or functional abnormalities when they are fully evaluated by more sensitive methods, such as ergometry and autonomic tests.³

Another possible explanation proposed by the authors would be the vasculitis phenomenon. Although there is good experimental evidence to suggest that changes in the microvasculature may contribute to chagasic heart disease,⁴ much less is known about the possible involvement of central nervous system microvasculature in Chagas’ disease. Indeed, most studies point to an important role for endothelin in the pathogenesis of microvascular changes in the chagasic heart,[4 5] but we are unaware of any similar studies of the central nervous system.

The authors also suggest the need for primary prevention in all patients with Chagas’ disease cardiomyopathy. This is a strong recommendation, as most chagasic patients derive from poor social economic backgrounds and have poor access to the health system.¹ Chronic oral anticoagulant therapy is known to cause frequent clinical complications, especially bleeding; an alternative approach could be use of the low dose anticoagulant therapy that has been recently suggested for the treatment of deep vein thrombosis.⁶ However, further studies are still needed to investigate this possibility specifically in Chagas’ disease.