Abstract Body: Introduction: Patients with heart failure (HF) often experience chronic stress arising from symptom burden and distress about the future. Chronic stress can be measured subjectively through questionnaires and objectively through biomarkers such as hair cortisol concentration (HCC). Cortisol, a catabolic hormone associated with skeletal muscle loss, may be associated with a decrease in physical activity (PA) tolerance. The interplay between chronic stress and PA may vary across different HF etiologies, including heart failure with reduced and preserved ejection fraction (HFpEF and HFrEF), and combined HF, due to differing underlying contributing factors. Therefore, this study aimed to examine the associations between perceived stress, HCC, and PA among patients with different HF etiologies.

Methods: In this cross-sectional study, perceived stress was measured using The Perceived Stress Scale (PSS-10). HCC (pg/mg) was derived from cortisol collected from hair samples (3cm long, 20mg in weight) and analyzed using enzyme immunoassay. The International Physical Activity Questionnaire Short form (s-IPAQ) was used to measure PA.

Results: The sample included 28 patients with HFrEF (mean EF: 41 ± 9%), 7 patients with HFpEF (mean EF: 54 ± 6%), and 11 patients with combined HF (mean EF: 43 ± 8%). Overall, participants were 71.8 + 11.2 years old, 44% female, 87% White, 4% Black, and 9% Hispanic. HCC was not significantly associated with perceived stress in any group. However, HCC was strongly and positively associated with PA among patients with HFpEF (r = 0.91, p < 0.005), but not among patients with HFrEF (r = -0.09, p = 0.64) or combined HF (r = 0.26, p = 0.44).

Conclusions: The absence of correlation between perceived stress and HCC suggests a potential dissociation between psychological and physiological stress in HF patients which could be due to a blunted stress response in chronic illness or to use of adaptive coping. Despite a small sample, PA was significantly and positively associated with HCC among patients with HFpEF, which was unexpected. PA in HFpEF patients may serve as a physiological stressor that increases cortisol production to help regulate metabolism. Because HFpEF is often associated with chronic inflammation, metabolic syndrome, and other morbidities, physical exertion may also augment the stress response. Further research examining the association between chronic stress and PA with larger samples and objectively measured PA measures is needed.