Prognostic value of serum brain-derived neurotrophic factor levels in patients with Chagas cardiomyopathy

BACKGROUND Serum brain-derived neurotrophic factor (BDNF) levels have been shown to be lower in patients with Chagas cardiomyopathy (ChC) than in patients with non-dilated chagasic cardiomyopathy. However, its prognostic value was not established in patients with ChC. METHODS Forty-nine patients with ChC (50 ± 7 years, New York Heart Association "NYHA" I-III); were evaluated by echocardiography, exercise testing, and blood analysis. Serum BDNF levels were determined using enzyme-linked immunosorbent assay sandwich. Patients were followed-up, and cardiac death was considered the end-point. The survival analyses were performed using Kaplan-Meier and Cox regression. RESULTS After 39 ± 14 months of follow-up, 12 patients (25%) died. The concentration of 2.5 ng/mL was the optimal cut-off value to predict survival with significant difference between the groups with low (≤ 2.5 ng/mL) and high (> 2.5 ng/mL) BDNF levels (p = 0.006). Lower serum BDNF levels (hazards ratio (HR) 1.1, 95% confidence interval (CI) 1.1-1.4; p = 0.001), peak oxygen uptake (HR 1.2, 95% CI 1.0-1.3; p = 0.009), and left ventricular ejection fraction (HR 0.8, 95% CI 0.7-0.9; p = 0.001) were the independent predictors of survival. The combination of low serum BDNF levels and reduced left ventricular ejection fraction were highly predictive of death (HR 5.6, 95% CI: 1.2-9.7; p = 0.026). CONCLUSION In patients with ChC, reduced serum BDNF levels, especially if associated with systolic function, may provide useful prognostic information.

Treinamento muscular inspiratório na doença pulmonar obstrutiva crônica: impacto na qualidade de vida, intolerância ao esforço e dispnéia / Inspiratory muscle training in chronic obstructive pulmonary disease: impact on quality of life, exercise intolerance, and dyspnea

O treinamento muscular inspiratório (TMI) tem demonstrado efeitos positivos na melhora da função muscular inspiratória, porém seus efeitos sobre a intolerância ao esforço e a qualidade de vida ainda precisam ser esclarecidos. Este estudo visou avaliar...

Inspiratory muscle training (IMT) has shown beneficial effects concerning inspiratory muscle function, but its effects on exercise intolerance and quality of life are not clearly established...