Background
: No-reflow after primary percutaneous coronary intervention (PCI) remains a clinical challenge. Erythropoietin (EPO) has been associated with reduced infarct size due to EPO’s antiapoptotic and nitric oxide enhancing effects. We aimed to assess the association between EPO serum levels measured on admission and angiographic no-reflow in patients undergoing primary PCI.
Methods
: From a consecutive series of 60 patients presenting with ST elevation myocardial infarction within 12 h of chest pain onset and undergoing successful primary PCI (i.e. residual stenosis < 20%), we included 48 patients (age 61±12 years, male sex 89%), comprising the first 24 with no-reflow and the first 24 without no reflow. Patients with iron deficiency, recent transfusions, liver or lung failure, other haematological disorders or undergoing treatment with EPO were excluded. EPO levels were measured by ELISA before PCI. Clinical, enzymatic, procedural and angiographic data were also collected. No-reflow was defined as a coronary TIMI flow grade ≤ 2 after vessel reopening or as a TIMI flow grade of 3 with a final myocardial blush grade <2. Multivariate predictors of no-reflow were assessed by logistic regression analysis (SPSS 13).
Results
: Patients with and without no-reflow did not differ significantly in age, sex, cardiovascular risk factors or standard therapy for acute myocardial infarction. Thrombus aspiration was used in 16 patients (32%) whereas abciximab in 31 (63%), and they did not differ between the two groups. Patients with angiographic no-reflow had lower EPO serum levels compared to those having angiographic reflow (4.2 (0.56 –9.5) vs 12.2 (5.7–20.2) mUI/ml, p=0.001). The left anterior descending artery (LAD) was the culprit vessel in 83% of patients having no-reflow as compared to 30% of those having reflow (p<0.0001). At multivariate analysis, including EPO levels, culprit artery and symptoms to balloon time, the independent predictors of no-reflow were LAD as culprit vessel (OR 15, 95% CI 3–75, p=0.001) and low EPO serum levels (OR 0.91, 95% CI 0.84 – 0.99, p=0.048).
Conclusion
: These data suggest a significant role for EPO in modulating microcirculatory injury after mechanical reperfusion in patients with ST elevation myocardial infarction.