Exercise tests in Chagas cardiomyopathy: an overview of functional evaluation, prognostic significance, and current challenges

Abstract

Patients with Chagas cardiomyopathy (ChC) usually progress with fatigue and dyspnea. Exercise tests are valuable for the functional evaluation of these patients. However, information about the applicability of the exercise tests is scattered, and no studies have systematically reviewed the results. Thus, the present review explored the general aspects and prognostic value of exercise tests in patients with ChC. A literature search of the MEDLINE, Web of Science, CINAHL, Scopus, and LILACS databases was performed to identify relevant studies. There were no data restrictions, and articles that met the objective of the study were selected. Articles written in English, Portuguese, and Spanish were considered, and 25 articles were finally included. The peak oxygen uptake (VO2peak) was correlated with demographic and echocardiographic variables. Echocardiographic features of the left ventricular diastolic function and right ventricular systolic function appeared to be determinants of functional capacity, in addition to age and sex. VO2peak was associated with higher mortality, especially in patients with dilated ChC. The minute ventilation/carbon dioxide production slope (VE/VCO2 slope) was a strong predictor of survival; however, more studies are needed to verify this observation. Field tests showed moderate to strong correlation with VO2peak and thus may be inexpensive tools for the functional evaluation of patients with ChC. However, few studies have verified their prognostic significance. While exercise tests are useful tools for functional assessment, information is scarce regarding further considerations, and many of the criteria are based on guidelines for other heart diseases.

The health-related quality of life in patients with Chagas disease: the state of the art

“…in patients with ChC 40 . Two studies included in this review verified the association between VO2peak and HRQoL, assessed using the MLwHFQ and SF-36.…”

“…Functional capacity, assessed by both peak oxygen uptake (VO2peak) and field tests, has clinical and prognostic importance in patients with ChC 40 . Two studies included in this review verified the association between VO2peak and HRQoL, assessed using the MLwHFQ and SF-36.…”

Effect of combined physical exercise program on improving the functional capacity and the cardiac autonomic modulation of Chagas cardiomyopathy

“…Cardiac remodeling induced by pathogens in ChC can lead to a progressive reduction in cardiac performance with an impact on the functional capacity of individuals. In this context, cardiac damage, abnormalities of the sympathetic-vagal balance, poor diet, chronic and systematic inflammatory process, medications, and physical inactivity could explain intolerance to physical exercise, muscle weakness, and worsening of the quality of life of patients with ChC [1][2][3] .…”

“…Oxygen consumption at peak effort (VO 2 peak), metabolic thresholds, ventilatory efficiency (VE/VCO2slope) with gravity marker, and presence of periodic breathing (PB) have been evaluated in the ChC 1,2,4 . However, few studies have investigated the effects of a combined formal exercise program with aerobic exercise and strength exercise in patients with ChC with LVD.…”

Determinants of minute ventilation-carbon dioxide production relationship in Chagas cardiomyopathy

“…In the setting of ChC, Ritt et al 6 reported that the VE/VCO 2 slope was the only independent predictor of a worse prognosis (cut-off value of 32.5) among the variables evaluated by the CPET. However, unlike heart failure, few studies have evaluated the VE/VCO 2 slope in patients with ChC 7 , and no study has demonstrated the determinants of the VE/VCO 2 slope in this population. Thus, the present study aimed to verify the clinical, echocardiographic, and functional determinants of the VE/VCO 2 slope in patients with ChC.…”