['The aim of this study was to establish erythropoietin as a\xa0protective factor against brain ischemia during open heart surgery.', 'A total of 36\xa0consecutive patients scheduled for revascularization heart surgery were included in the study. Of the patients 18 received 3\xa0intravenous doses of recombinant human erythropoietin (rHuEpo, 24,000\xa0IU) and 18\xa0patients received a\xa0placebo. Magnetic resonance imaging (MRI) to detect new brain ischemic lesions was performed. Additionally, S100A, S100B, neuron-specific enolase\xa0A and\xa0B (NSE-A and\xa0B) and the concentration of antibodies against N‑methyl-D-aspartate receptors (NMDAR) to identify new neurological complications were determined.', 'Patients who received rHuEpo showed no postoperative ischemic changes in the brain on MRI images. In the control group 5 (27.8\u2009%) new ischemic lesions were found. The NMDAR antibody concentration, S100A, S100B and NSE showed no significant differences between the groups for new cerebral ischemia. High levels of lactate before and after external aortic compression (p\xa0= 0.022 and p\xa0= 0.048, respectively) and duration of operation could predict new ischemic lesions (p\xa0= 0.009).'] Does perioperative erythropoietin protect the CNS against ischemic lesions in patients after open heart surgery?