Relação entre capacidade funcional, funcionalidade, qualidade de sono e consumo de oxigênio de pico em indivíduos com insuficiência cardíaca

Abstract

The clinical condition of people with heart failure (HF) involves challenges that go beyond the structural and functional dysfunctions of the condition, negatively affecting their quality of life and functioning of these individuals. To assess the functional capacity of individuals with HF, the cardiopulmonary exercise test (CPET) is the gold standard tool. However, the availability of the CPET is low in contexts of limited resources, and it is commonly replaced by the Duke Activity Status Index (DASI), a simple instrument that predicts peak oxygen consumption (VO2peak) based on the answer provided by the individual to 12 questions. Although very practical and widely used to guide cardiac rehabilitation protocols for individuals with HF, the DASI estimates VO2peak without considering clinical variables that influence the functional capacity of this population. In view of the above, two studies were conducted and are presented in this dissertation. The first aimed to evaluate whether the DASI as a tool for estimating VO2peak in patients with heart failure. The results showed a moderate positive correlation between the DASI score and VO2peak, with a high concordance bias between the methods for patients with HF. The adjustment made to the regression model (VO2peak= 27.053 - 0.283 x Age + 4.833 x Sex + 0.155 x DASI score) improved the predictive capacity of the DASI, specifically considering its application to individuals with HF. In the second study of this dissertation, considering the importance of various influential factors in the context of HF, we sought to verify which facotrs are associated with disability in the population studied. It was observed that individuals with New York Heart Association (NYHA) functional classification ≥ II showed greater disability in all the domains assessed (cognition, mobility, self-care, getting along, life activities and participation). Gains in functional capacity assessed by the DASI were shown to have a protective effect on various domains of the World Health Disability Assessment Schedule (WHODAS) and on the total score. Comorbidities such as diabetes and a history of smoking caused impairments of 48% and 39% in mobility, respectively, whereas dyslipidemia negatively impacted cognition by 63%. The left ventricular ejection fraction had a protective effect against participation and total functioning. Sleep quality proved to be a crucial factor, with high levels of sleep disturbance associated with a 130% increase in impairment in the self-care domain. The results of these two studies can help health professionals involved in the care of patients with HF to obtain a comprehensive view of functioning and estimate the VO2peak of HF individuals with greater predictive capacity using an instrument that is accessible in any care setting.