The association between variables of cardiopulmonary exercise test and quality of life in patients with chronic Chagas cardiomyopathy (Insights from the PEACH STUDY)

Studies investigating the association between functional capacity and quality of life (QoL) in individuals with chronic Chagas cardiomyopathy (CCC) usually do not include a gold-standard evaluation of functional capacity, limiting the validity and the interpretation of the results. The present study is a cross-section analysis aiming to evaluate the association between functional capacity (quantified by cardiopulmonary exercise test [CPET]) and QoL in individuals with CCC. QoL was assessed using the SF-36 questionnaire. Sociodemographic, anthropometric, clinical, cardiac function and maximal progressive CPET variables were obtained from PEACH study. Generalized linear models adjusted for age, sex, and left ventricular ejection fraction were performed to evaluate the association between CPET variables and QoL. After adjustments, VO2 peak and VO2 AT were both associated with physical functioning (beta = +0.05 and beta = +0.05, respectively) and physical component summary (beta = +0.03 and beta = +0.03, respectively). Double product was associated with physical functioning (beta = +0.003), general health perceptions (beta = +0.003), physical component summary (beta = +0.002), and vitality (beta = +0.004). HRR <= 12bpm was associated with physical functioning (beta = -0.32), role limitations due to physical problems (beta = -0.87), bodily pain (beta = -0.26), physical component summary (beta = -0.21), vitality (beta = -0.38), and mental health (beta = -0.19). VE/VCO2 slope presented association with all mental scales of SF-36: vitality (beta = -0.028), social functioning (beta = -0.024), role limitations due to emotional problems (beta = -0.06), mental health (beta = -0.04), and mental component summary (beta = -0.02). The associations between CPET variables and QoL demonstrate the importance of CPET inclusion for a more comprehensive evaluation of individuals with CCC. In this setting, intervention strategies aiming to improve functional capacity may also promote additional benefits on QoL and should be incorporated as a treatment strategy for patients with CCC.