The effect of intravenous administration of erythropoietin on the infarct size in primary percutaneous coronary intervention.

Background: After an acute myocardial infarction, the early restoration of coronary blood flow is mandatory for reducing infarct size. However, the process of reperfusion itself may also cause irreversible myocardial injury and contribute to the final infarct size. Recent animal studies have suggested that erythropoietin could protect the myocardium when administered after the onset of reperfusion. We investigated whether the administration of erythropoietin at the time of PCI would limit the size of the infarct during acute myocardial infarction by analysis of MRI and cardiac enzymes in this pilot study.

Methods: We randomly assigned 57 patients with acute, anterior wall ST-elevation myocardial infarction who were presented within 12h after the onset of chest pain to one group which was given an intravenous bolus of recombinant human erythropoietin (rhEPO, 50 U/kg) immediately before undergoing PCI or the control group without the IV treatment before PCI. Infarct size was assessed by measuring the release of cardiac enzymes (CK, CK-MB) and by performing MRI on day 4 after infarction.

Results: The injection of erythropoietin did not result in thrombotic or hypertensive complications. The release of cardiac enzyme was not different between two groups. On day 4, the absolute infarct volume of the area of hyperenhancement on MRI did not differ between two groups (EPO group 52.4 ± 23.6 cm(3) vs. control group 54.8 ± 28.6 cm(3), p=0.74). Two groups did not differ in the percentage of total infarct volume over left ventricle volume (EPO group 34.4 ± 11.7% vs. 37.0 ± 13.8%, p=0.50).

Conclusions: Intravenous administration of erythropoietin was safe and was not associated with thrombotic or hypertensive side effects. However, it did not reduce the infarct size when assessed by MRI and cardiac enzyme. Further studies about the dose or routes of administration of EPO are needed (ClinicalTrials.gov Identifier NCT00882466).