Resumo Fundamento: A doença de Chagas leva à redução da capacidade funcional. Entretanto, o estágio em que o comprometimento funcional é detectável permanece obscuro. Objetivos: O presente estudo teve como objetivo comparar a capacidade funcional de pacientes em diferentes estágios da doença de Chagas e de indivíduos saudáveis e verificar os determinantes do consumo de oxigênio de pico (VO2pico). Métodos: Em um estudo transversal, foram selecionados 160 indivíduos, 35 saudáveis e 125 com doença de Chagas. No grupo chagásico, 61 (49%) estavam na forma indeterminada da doença, 45 (36%) com cardiomiopatia chagásica (CC) e função cardíaca preservada e 19 (15%) com disfunção cardíaca e CC dilatada. Os dados foram analisados por meio de análise de regressão univariada e multivariada. A significância estatística foi fixada em 5%. Resultados: Pacientes na forma indeterminada da doença apresentaram capacidade funcional semelhante a indivíduos saudáveis (p> 0,05). Pacientes com ChC e função cardíaca preservada apresentaram VO2pico menor que os pacientes na forma indeterminada (p <0,05), mas apresentaram valores de VO2pico semelhantes ao ChC dilatado (p = 0,46). A idade, sexo masculino, classe funcional da NYHA, pressão arterial diastólica, razão entre a velocidade do fluxo transmitral diastólico precoce e a velocidade anular mitral diastólica precoce, a fração de ejeção do ventrículo esquerdo (FEVE) e o diâmetro diastólico final do ventrículo esquerdo foram associados à capacidade funcional. Porém, apenas idade, sexo masculino, FEVE e classe funcional da NYHA permaneceram associados ao VO2pico no modelo final (R2 ajustado = 0,60). Conclusão: Pacientes com CC apresentam menor capacidade funcional do que pacientes na forma indeterminada. FEVE, idade, sexo masculino e classe funcional da NYHA foram determinantes do VO2pico em pacientes com doença de Chagas.

Abstract Background: Chagas disease leads to reduced functional capacity. However, the stage at which functional impairment is detectable remains unclear. Objectives: The present study was addressed to compare the functional capacity of patients at different stages of Chagas disease and healthy individuals and to verify the determinants of peak oxygen uptake (VO2peak). Methods: In a cross-sectional study, 160 individuals were selected, 35 healthy and 125 with Chagas disease. In the Chagasic group, 61 (49%) were in the indeterminate form of the disease, 45 (36%) with Chagas cardiomyopathy (ChC) and preserved cardiac function and 19 (15%) with cardiac dysfunction and dilated ChC. The data were analyzed using univariate and multivariate regression analysis. Statistical significance was set at 5%. Results: Patients in the indeterminate form of disease showed similar functional capacity to healthy individuals (p>0.05). Patients with ChC and preserved cardiac function had lower VO2peak than patients in the indeterminate form (p<0.05), but showed similar VO2peak values than dilated ChC (p=0.46). The age, male sex, NYHA functional class, diastolic blood pressure, ratio of the early diastolic transmitral flow velocity to early diastolic mitral annular velocity, left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter were associated with functional capacity. However, only age, male sex, LVEF and NYHA functional class, remained associated with VO2peak in the final model (adjusted R2=0.60). Conclusion: Patients with ChC had lower functional capacity than patients in the indeterminate form. LVEF, age, male sex and NYHA functional class were determinants with VO2peak in patients with Chagas disease.

Abstract INTRODUCTION: Chagas cardiomyopathy (ChC) is highly stigmatized, and the presence of depressive symptoms may be a common feature. However, its determinants remain unclear. Therefore, the present study aimed to verify the prevalence of depression and the clinical, echocardiographic, functional, and quality of life factors associated with depressive symptoms in patients with ChC and predominantly preserved cardiac function. METHODS: Thirty-five patients with ChC (aged 40 to 60 years, 66% men, NYHA I-III) were evaluated by echocardiography, cardiopulmonary exercise testing, 6-minute walk test (6MWT), and Mini-Mental State Examination. Physical activity level was assessed using the Human Activity Profile (HAP) and health-related quality of life was assessed using the Short-Form Health Survey (SF-36). Depressive symptoms were evaluated using the Beck Depression Inventory. A cutoff point greater than 9 was indicative of depression. RESULTS: Depression was detected in 13 patients (37%). In the univariate analysis, female sex, NYHA functional class, body mass index, HAP score, mental summary of SF-36, peak oxygen uptake, and 6MWT distance were associated with depressive symptoms. The final model showed that only the HAP score (B = -0.533; 95% confidence interval [CI]: -0.804 to -0.262) and SF-36 mental summary (B = -0.269; 95% CI: -0.386 to -0.153) remained as independent predictors of depressive symptoms in patients with ChC. CONCLUSIONS: Depression was prevalent in patients with ChC and predominantly preserved cardiac function. Physical activity and mental health were independent risk factors for depressive symptoms.

Abstract Reduced peak oxygen uptake (VO2peak) is a common clinical finding in progressive Chagas disease. However, the disease stage in which functional impairment is detectable remains uncertain. The present study compared functional capacity between healthy controls and patients with different clinical forms of Chagas disease. A systematic review and meta-analysis (PROSPERO database CRD42017058353) was conducted following a search of the MEDLINE, Web of Science, CINAHL, and LILACS databases from September to December 2017 for articles published in English, Spanish, or Portuguese, with no date restrictions. We included studies that compared the VO2peak between healthy and Chagas disease patients, stratified according to 3 clinical forms [no apparent cardiac disease, non-dilated Chagas heart disease (CHD), and dilated CHD]. Seven cross-sectional studies were included. Chagas disease patients without apparent cardiac disease (n=208) had VO2peak values [mean difference, -1.55ml/kg/min; 95% confidence interval (CI), -4.98ml/kg/min to 1.88ml/kg/min] similar to those of healthy controls (n=105; p=0.38, I2=52%). In non-dilated CHD (n=159), VO2peak was 8.71ml/kg/min lower (95% CI, -13.99 to -3.42ml/kg/min) than in healthy controls (n=59; p=0.001, I2=75%). VO2peak was also significantly lower (mean difference, -9.30ml/kg/min; 95% CI, -11.34 to -7.25ml/kg/min) in dilated CHD patients (n=131) than in healthy controls (n=53; p<0.001, I2=0%). Exercise capacity in Chagas disease patients without apparent cardiac disease is similar to that in healthy controls. Functional impairment in Chagas disease is detectable in the early stages of cardiac involvement, even in the absence of systolic dysfunction and signs of heart failure.