Aims: We examined the adequacy of endogenous erythropoietin (EPO) levels for the degree of anaemia in patients with chronic heart failure (CHF) and its relation to prognosis.
Methods and results: We studied 74 anaemic CHF patients from a cohort of 240 patients. The adequacy of endogenous EPO levels was assessed by derived observed/predicted (O/P) ratio. A ratio value < 0.92 indicates EPO levels lower than expected, whereas a value > 1.09 indicates EPO levels higher than expected. The primary endpoint was mortality. During a median follow up of 4.9 years, 35 of the 74 (47.3%) anaemic patients died. EPO levels lower than expected were observed in 29 patients (39%), whereas EPO levels higher than expected were present in 22 anaemic patients (29%). The Kaplan-Meier analysis revealed that anaemic patients with EPO levels higher than expected had a significantly higher mortality rate compared to patients with EPO levels as expected or EPO levels lower than expected (log-rank: P = 0.024). A higher O/P ratio was an independent predictor of increased mortality risk adjusted for variables including age, sex, haemoglobin, NT-proBNP, and renal function; hazard ratio (HR): 1.020 95%CI (1.004-1.036), P = 0.012.
Conclusion: EPO levels higher than expected, suggesting resistance to the hormone, are common in CHF patients and are associated with a higher mortality.