Pedro Henrique Scheidt Figueiredo

Prediction of peak oxygen uptake in patients with Chagas heart disease: Value of the Six-minute Walk Test

Chagas disease, an infection caused by the protozoan Trypanosoma cruzi, affects about 10 million people worldwide and another 100 million are at risk of becoming infected [1]. In recent decades, changes in the epidemiological profile of Chagas disease has been observed leading to urbanization and globalization of the infection with increasing prevalence in North America and Europe [2]. Heart disease is the most severe clinical form of the Chagas disease [3] leading to exercise intolerance, especially in advanced stages of the disease. In clinical practice, peak oxygen uptake (VO2peak) is considered the best index of functional capacity (FC), exercise tolerance and cardiorespiratory function [4]. However, maximal exercise testing may not be available in endemic areas for Chagas disease, where usually have poor infrastructure and limited technological resources. An alternative approach is the Six-minute Walk Test (6MWT), a simple, inexpensive and effective tool in assessing FC in cardiac patients [5]. In patients with Chagas heart disease (CHD), the 6MWT was associated with echocardiographic variables [6], demonstrated the effectiveness of exercise-based intervention [7] and correlatedwith VO2peak [8]. However, compared to the VO2peak, the distance walked during the test provides limited information about the functional status of the patient

Reduced functional capacity in patients with Chagas disease: a systematic review with meta-analysis

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.

The role of the inspiratory muscle weakness in functional capacity in hemodialysis patients

Introduction Inspiratory muscle function may be affected in patients with End-Stage Renal Disease (ESRD), further worsening the functional loss in these individuals. However, the impact of inspiratory muscle weakness (IMW) on the functional capacity (FC) of hemodialysis patients remains unknown. Thus, the present study aimed to evaluate the impact of IMW on FC in ESRD patients undergoing hemodialysis. Materials and methods ESRD patients on hemodialysis treatment for more than six months were evaluated for inspiratory muscle strength and FC. Inspiratory muscle strength was evaluated based on maximal inspiratory pressure (MIP). IMW was defined as MIP values less than 70% of the predicted value. FC was evaluated using the Incremental Shuttle Walk test (ISWT). Patients whose predicted peak oxygen uptake (VO2peak) over the distance walked during the ISWT was less than 16mL/kg/min were considered to have FC impairment. Associations between variables were assessed by linear and logistic regression, with adjustment for age, sex, body mass index (BMI), presence of diabetes and hemoglobin level. Receiver-operating characteristic (ROC) analysis was used to determine different cutoff values of the MIP for normal inspiratory muscle strength and FC. Results Sixty-five ERSD patients (67.7% male), aged 48.2 (44.5–51.9) years were evaluated. MIP was an independent predictor of the distance walked during the ISWT (R2 = 0.44). IMW was an independent predictor of VO2peak < 16mL/kg/min. (OR = 5.7; p = 0.048) in adjusted logistic regression models. ROC curves showed that the MIP cutoff value of 82cmH2O had a sensitivity of 73.5% and specificity of 93.7% in predicting normal inspiratory strength and a sensitivity and specificity of 76.3% and 70.4%, respectively, in predicting VO2peak ≥ 16mL/kg/min. Conclusions IMW is associated with reduced FC in hemodialysis patients. Evaluation of the MIP may be important to functional monitoring in clinical practice and can help in the stratification of patients eligible to perform exercise testing.

Effects of the inspiratory muscle training and aerobic training on respiratory and functional parameters, inflammatory biomarkers, redox status and quality of life in hemodialysis patients: A randomized clinical trial

Objective Evaluate and compare the isolated and combined effects of Inspiratory Muscle Training (IMT) and Aerobic Training (AT) on respiratory and functional parameters, inflamatory biomarkers, redox status and health-related quality of life (HRQoL) in hemodialysis patients. Methods A randomised controlled trial with factorial allocation and intention-to-treat analysis was performed in hemodialysis patients. Volunteers were randomly assigned to performe 8-weeks of IMT at 50% of maximal inspiratory pressure (MIP), low intensity AT or combined training (CT). Before the interventions, all the volunteers went 8-weeks through a control period (without training). Measures are taken at baseline, 8-week (after control period) and 16-week (after the interventions). Primary outcomes were functional capacity (incremental shuttle walk test), MIP and lower limbs strength (Sit-to-Stand test of 30 seconds). Plasma levels of interleukin-6 (IL-6), soluble tumor necrosis factor receptor 1 (sTNFR1) and 2 (sTNFR2), adiponectin, resistin and leptin, redox status parameters and HRQoL (KDQOL-SF questionnaire) were the scondary outcomes. Data analyses were performed by two-way repeated measurements ANOVA. Results 37 hemodialysis patients aged 48.2 years old (IC95% 43.2–54.7) were randomized. Increase of MIP, functional capacity, lower limbs strength and resistin levels, and reduction of sTNFR2 levels in 16-week, compared to baseline and 8-week, were observed in all the groups (p<0.001). IMT improved functional capacity, MIP and lower limbs strength in 96.7m (IC95% 5.6–189.9), 34.5cmH2O (IC95% 22.4–46.7) and 2.2repetitions (IC95% 1.1–3.2) respectively. Increase in resistin leves and reduction in sTNFR2 leves after IMT was 0.8ng/dL (IC95% 0.5–1.1) and 0.8ng/dL (IC95% 0.3–1.3), respectively, without between-group differences. Compared to baseline and 8-week, adiponectin levels (p<0.001) and fatigue domain of the HRQoL (p<0.05) increased in 16-week only in CT. Conclusion IMT, AT and CT improved functional parameters and modulated inflammatory biomarkers, in addition, IMT provoked a similar response to low intensity AT in hemodialysis patients. Trial registration Registro Brasileiro de Ensaios clínicos RBR-4hv9rs.

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.

Novel Physiotherapies in the Setting of Chagas Heart Disease: A Summarized Review of Functional Evaluation

Introduction: Chagas disease remains a public health problem in Latin America and currently in non-endemic countries. The cardiac form is the most severe and exercise training has been shown to be effective in the treatment of these patients. However, a review of the clinical findings of pre-training assessment is necessary to guide the exercise prescription. Objective: to describe the cycle of the disease and the physiotherapeutic evaluation and of patients with Chagas disease, focusing on the patient with cardiopathy.Methods: a literature search in MEDLINE/Pubmed, Scientific Electronic Library Online, Cumulative Index of Nursing and Allied Health Literature, Latin American and Caribbean Health Sciences Literature and Web of Science databases performed between November 2017 and January 2018.Results: In the anamnesis, drug therapy and functional class of the New York Heart Association should be investigated. In the maximum exercise testing, the presence of ventricular arrhythmias, the peak of oxygen uptake and the slope of increase of ventilation relative to carbondioxide production may assist in the functional evaluation, risk stratification and prognosis establishment. Field tests, such as the Six-Minute Walk Test and Incremental Shuttle Walk Test, are inexpensive and effective in functional assessment. Respiratory evaluation has received special attention in recent years by the prevalence of inspiratory muscle weakness. Finally, quality of life is a crucial point in the evaluation of the chagasic patient, mainly due to the stigmatizing nature of the disease.Conclusion: The peculiarities of Chagas heart disease should be taken into account in the functional evaluation of the patient and plays a key role in the exercise prescription before physical training.