The aim of the study: To evaluate the chronic fatigue and its relation to the function of hypothalamus-pituitary-adrenal axis in patients with New York Heart Association (NYHA) functional class III-IV chronic heart failure.
Material and methods: A total of 170 patients with NYHA functional class III-IV chronic heart failure completed MFI-20L, DUFS, and DEFS questionnaires assessing chronic fatigue and underwent echocardiography. Blood cortisol concentration was assessed at 8:00 am and 3:00 pm, and plasma N-terminal brain natriuretic pro-peptide (NT-proBNP) concentration was measured at 8:00 am. Neurohumoral investigations were repeated before cardiopulmonary exercise test and after it.
Results: The results of all questionnaires showed that 100% of patients with NYHA functional class III-IV heart failure complained of chronic fatigue. The level of overall fatigue was 54.5+/-31.5 points; physical fatigue - 56.8+/-24.6 points. Blood cortisol concentration at 8:00 am was normal (410.1+/-175.1 mmol/L) in majority of patients. Decreased concentration was only in four patients (122.4+/-15.5 mmol/L); one of these patients underwent heart transplantation. In the afternoon, blood cortisol concentration was insufficiently decreased (355.6+/-160.3 mmol/L); reaction to a physical stress was attenuated (Delta 92.9 mmol/L). Plasma NT-proBNP concentration was 2188.9+/-1852.2 pg/L; reaction to a physical stress was diminished (Delta 490.3 pg/L).
Conclusion: All patients with NYHA class III-IV heart failure complained of daily chronic fatigue. Insufficiently decreased blood cortisol concentration in the afternoon showed that in the presence of chronic fatigue in long-term cardiovascular organic disease, disorder of a hypothalamus-pituitary-adrenal axis is involved.