Search

Abstract: Background: Right ventricular (RV) involvement is a typical feature of Chagas'' disease. In patients with congestive heart failure of other etiologies, RV dysfunction is a strong indicator of poor prognosis. However, the prognostic value of RV dysfunction in patients with Chagas'' cardiomyopathy has not been reported. This study sought to investigate the prognostic value of RV dysfunction, apart from other well established risk factors, in patients with Chagas'' cardiomyopathy. Methods: The study enrolled 158 patients (99 men; mean age of 48±12 years) from a tertiary center for Chagas'' disease. Patients were selected if found to have both the diagnosis of Chagas'' disease and cardiomyopathy. All patients underwent a comprehensive Doppler echocardiogram and the global RV function was quantitatively assessed using the RV index of myocardial performance (Tei index). Results: Most of the patients were in NYHA classes I and II (79%). During a mean follow up of 34±23 months, 44 patients (28%) died: 24 (55%) patients died of progressive heart failure and 16 (36%) of sudden death. RV Tei index emerged as an independent predictor of survival (hazard ratio 5.75, 95% confidence interval 1.69 to 19.51). Kaplan–Meier survival curves showed a higher cumulative mortality among patients in the highest quartile of RV Tei index, compared with other 3 quartiles (log-rank statistic 21.87, p <0.001). After adjustment for clinical data and LV ejection fraction, RV Tei index in the highest quartile (>0.56) remained a significant predictor of death (hazard ratio 5.29, 95% confidence interval 2.43 to 11.52). Conclusions: RV function assessed by the Tei index added significant prognostic information, incremental to the NYHA clinical classification and to the standard echocardiographic evaluation of LV systolic function. A simple measure of a Doppler index, which allows analysis of both systolic and diastolic function of the RV, appears to be a useful non-invasive tool for risk stratification in patients with dilated chronic Chagas'' cardiomyopathy. [Copyright &y& Elsevier]

Human infection with the protozoan parasite Trypanosoma cruzi leads to Chagas disease, which affects ∼17 million people in Latin America. A significant percentage of the infected population will develop clinical symptoms or present changes in laboratory and/or image evaluation. The existence of a large spectrum of clinical manifestations – with patients ranging from asymptomatic to severe cardiac involvement – emphasizes the need to use standardized and well-defined clinical criteria among different research groups. In this article, we carry out a systematic review of the immunology in human Chagas disease, discussing recent findings in the context of a clinical perspective. [Copyright &y& Elsevier]

Left ventricular dysfunction in Chagas’ disease is common but can be difficult to detect. We investigated whether measurement of plasma brain natriuretic peptide (BNP) could identify patients with left ventricular dysfunction who need further investigation or treatment. Among patients with an abnormal electrocardiogram or chest radiograph, a BNP concentration of 60·7 pmol/L or higher has a sensitivity and positive predictive value of 80%, and specificity and negative predictive value of 97%. Measurement of plasma BNP concentration could be a useful method to screen patients with Chagas’ disease. [Copyright &y& Elsevier]

Objective: The objective of this study was to determine the safety and efficacy of renin-angiotensin system (RAS) inhibitors and β-blockers in chronic Chagas cardiomyopathy. Background: Chronic Chagas cardiomyopathy causes substantial morbidity and mortality in Latin America. Whether RAS inhibitors and β-blockers are safe and beneficial has been challenged because of the lack of formal trials. Methods: We conducted a double-blind, placebo-controlled, and randomized trial in 42 patients with Trypanosoma cruzi infection and cardiomyopathy. All patients received enalapril (up-titrated to 20 mg BID) and spironolactone (25 mg QD). Subsequently, the patients were randomly assigned to receive placebo (n = 20) or carvedilol up-titrated to 25 mg BID (n = 19). The primary end points were change in left ventricular ejection fraction (LVEF) after RAS inhibition and that after the addition of carvedilol. The secondary end points were changes in other echocardiographic parameters, Framingham score, quality of life (36-item Short-Form Health Survey), New York Heart Association class, radiographic indices, brain natriuretic peptide levels, and chemokines as well as safety end points. Results: Optimization of RAS inhibition was safe, hemodynamically well tolerated, and associated with improvements in Framingham score (P = .001) and quality of life as well as reductions in the cardiothoracic index (P = .002), brain natriuretic peptide level (P = .032), and RANTES (regulated on activation, normal T expressed and secreted) level (P = .001). Left ventricular ejection fraction increased by 2.3% (P = .25); in patients with an LVEF ≤45% at baseline, it increased by 2.8% (P = .017). Treatment with carvedilol was associated with a trend toward an increase in LVEF (absolute difference between groups, 2.3%; P = .094). The addition of carvedilol was safe, hemodynamically well tolerated, and not associated with symptomatic bradycardia. Conclusions: In patients with chronic Chagas cardiomyopathy, optimization of treatment with enalapril and spironolactone and subsequent addition of carvedilol were safe and associated with benefits in cardiac function and clinical status. Larger trials are needed to show effects on mortality and/or hospitalization. [Copyright &y& Elsevier]

Abstract: Background: Left ventricular dysfunction (LVd) is the main predictor of mortality in Chagas disease (ChD). Aims: To compare the diagnostic performance of the conventional approach (ECG and chest X-ray) in the recognition of LVd in ChD, with a new strategy, in which BNP is measured in patients with an abnormal ECG. Methods: Consecutive ChD patients recruited at an Outpatient Reference Center in Belo Horizonte, Brazil, without other systemic diseases, in 1998–99 (sample 1, n =165) and in 2001–02 (sample 2, n =62) underwent ECG, chest X-ray, BNP measurement and echocardiography. Results: The prevalence of LVd (ejection fraction ≤0.40) was 9.1% in the sample 1. The conventional strategy recognized all patients with LVd (sensitivity: 100%, 95% CI: 79.6–100% and negative predictive value −PV 100%, 92.1–100%), but with low specificity (30%, 95% CI: 23.2–37.8) and +PV (12.5%, 95% IC: I7.7–19.6). The BNP/ECG strategy showed significantly better specificity (96.0%, 95% CI: 91.5–98.2, p <0.001) and +PV (66.7%, 95% CI: 43.7–83.7, p <0.001), and non-significantly lower sensitivity (80.0%, 95% CI: 54.8–93.0, p =0.25) and −PV (98.0%,95% CI: 94.2–99.3, p =0.08). Overall accuracy was improved with the new strategy. (94.5%,95% CI: 90.0–97.1×36.4%, 95% CI: 29.4–43.9, p <0.001). Similar results were obtained for the sample 2. Conclusions: The BNP-based strategy was more accurate than the conventional approach in the detection of LVd in ChD patients and should be considered as a valid option. [Copyright &y& Elsevier]