Relação da função pulmonar com capacidade funcional, fadiga e qualidade de vida em pacientes adultos com insuficiência cardíaca

Abstract

Heart failure (HF) is a complex clinical syndrome that affects functional capacity, quality of life, and multiple organ systems, and is frequently associated with pulmonary impairment. This study aimed to investigate the relationship between the degree of pulmonary function impairment, assessed through spirometric parameters, and functional capacity, fatigue, and quality of life in adult patients with HF. This was a quantitative, analytical-descriptive, cross- sectional study analyzing data from 226 patients with a clinical diagnosis of HF. Initial data were extracted from a database derived from patients’ medical records. Subsequently, functional assessment was performed using the Duke Activity Status Index (DASI), dyspnea (fatigue) was evaluated using the Medical Research Council scale (mMRC), and quality of life was assessed with the Minnesota Living with Heart Failure Questionnaire (MLHFQ). Finally, pulmonary function testing—spirometry—was conducted. Statistical analysis included descriptive measures, Pearson’s chi-square and Fisher’s exact association tests, as well as Spearman correlation analyses, adopting a significance level of 5%. The sample consisted predominantly of women (58.8%), with a mean age of 48.72 ± 8.66 years. The results indicated a high prevalence of ventilatory disorders (81.0%), with the restrictive pattern being the most frequent (34.1%), followed by the obstructive pattern (30.5%). A statistically significant and strong association was observed between the type of ventilatory disorder and the severity of pulmonary impairment (p < 0.001), with the mixed pattern invariably associated with the severe impairment category. Physical inactivity was also significantly associated with worse degrees of pulmonary dysfunction (p = 0.006). However, no statistically significant associations were identified between the degree of pulmonary impairment and scores of functional capacity (p = 0.124), fatigue (p = 0.293), or overall quality of life (p = 0.661). Confirming these findings, Spearman correlation coefficients between the severity of pulmonary impairment and these variables were not significant (|r| < 0.12; p > 0.05). Alterations in pulmonary function are extremely prevalent in patients with HF, and the strong association between the mixed ventilatory pattern and severe dysfunction may characterize a subgroup with greater pathophysiological complexity. The association with physical inactivity reinforces the vicious cycle between physical deconditioning and cardiorespiratory limitation. The absence of a significant correlation between pulmonary dysfunction and subjective measures of functional capacity, fatigue, and quality of life is a clinically relevant finding, suggesting that patients’ perceptions of their own functioning and well-being are modulated by a range of factors beyond spirometric parameters, including psychosocial aspects, adaptive mechanisms to chronicity, severity of cardiac dysfunction, and the presence of other comorbidities. It is concluded that although spirometric assessment is valuable for identifying and characterizing ventilatory disorders prevalent in HF, it does not, in isolation, constitute a robust predictor of perceived functional limitation or quality of life in this population.