Hypoxic regulation of erythropoietin secretion in heart failure patients undergoing elective surgery under cardiopulmonary bypass

Objective. To determine the relationship between severity of hypoxia and EPO production in heart failure (HF) candidates listed for surgery under cardiopulmonary bypass. Material and methods. A prospective cohort study included 29 patients with HF resulting from heart valve disease and/or coronary artery disease. Cardiopulmonary exercise test (CPET), serum EPO and O/P ratio (ratio of observed to predicted logEPO) were analyzed to compare severity of hypoxia and EPO release. Results. Serum EPO and O/P ratio were not associated with hematologic parameters and serum B-type natriuretic peptide (BNP). Minute ventilation/carbon dioxide production (VE/VCO2) was predicted by EPO level, hemoglobin level, O/P ratio, end-systolic volume, end-diastolic volume and left ventricular ejection fraction. In multivariate model, VE/VCO2 was predicted by serum EPO. EPO<16.8 IU/mL indicated higher peak oxygen consumption (VO2 peak), higher carbon dioxide (CO2) production, improved exercise tolerance, and better postoperative outcomes. Conclusion. Serum EPO in patients with heart failure can be an objective criterion for severity of circulatory hypoxia.