RESUMO
BACKGROUND: Chagas disease is endemic in South and Central America, where 18 million individuals are infected by Trypanosoma cruzi, causing congestive heart failure (CHF) and cardioembolic stroke. Transcranial Doppler (TCD) is able to detect real-time microembolic signals (MES) to the brain vessels and may represent a surrogate marker of stroke risk. We aimed to determine predictors of MES in a population of patients with CHF. METHODS: Consecutive CHF patients from a university-based cardiomyopathy clinic underwent TCD recording of the middle cerebral artery for 60 min by a single investigator who was blinded to all clinical data including cardiomyopathy etiology. Predictors of MES were sought by multivariable logistic regression analysis. RESULTS: From April 2004 to February 2009, 144 patients were studied, including 62 (44.6%) patients with Chagas disease. MES were detected in 9 (6.2%) patients and were more frequent in patients with Chagas disease than in patients with other causes of CHF (12.9 vs. 1.2%, p = 0.005). In multivariate analysis corrected for age and left-ventricular ejection fraction, predictors of MES were Chagas disease (odds ratio = 1.15, 95% confidence interval = 1.05-1.26, p = 0.004) and stroke history (odds ratio = 1.27, 95% confidence interval = 1.08-1.50, p = 0.005). CONCLUSIONS: Chagas disease and stroke history are risk factors for MES independent of cardiac disease severity. Other mechanisms besides structural cardiac disease may be operative, increasing embolic risk in Chagas disease.