Association of Exercise Capacity with Physical Functionality and Various Aspects of Fatigue in Patients with Coronary Artery Disease

The aim of this study was to examine associations between exercise capacity-indexed as the metabolic equivalent of the task-and various aspects of subjective fatigue, physical functionality, and depression in patients with coronary artery disease. A cross-sectional design was used. Patients with stable coronary artery disease (N = 240) underwent an exercise stress test and completed self-report assessments of depression, subjective physical limitations, vital exhaustion, and the impact of fatigue on physical, social, and cognitive functions. Associations between exercise capacity and these self-report variables were assessed using bivariate correlations and a series of multivariate regressions. Exercise capacity was negatively associated with vital exhaustion, physical limitations, and impact of fatigue on physical and social functioning but not on cognitive functioning. There was a marginal association between exercise capacity and depression. The associations between exercise capacity and fatigue remained significant even after controlling for effects of age, body mass index, gender, education, and comorbid diabetes mellitus. The main conclusion of the study is that in patients with coronary artery disease, exercise capacity has the strongest predictability for physical fatigue, but, importantly, it also independently predicts the feeling of loss of energy and malaise.