Differential effects of prasugrel and ticagrelor on endothelial progenitor cells during ST-elevation myocardial infarction

Background: Circulating endothelial progenitor cells (EPCs) have an important role in the process of vascular injury repair and the pathophysiology of coronary artery disease. Moreover, endothelial dysfunction is correlated with major adverse cardiac events in atherosclerotic patients. So far, the effects of novel P2Y12 inhibitors (Prasugrel and Ticagrelor) on EPCs have only been studied in the sub-acute phase following acute coronary syndrome. Our aims were to assess differences in the effect of these two medications on EPCs at the acute phase of ST-elevation myocardial infarction (STEMI). Methods: EPCs were isolated from peripheral blood samples, drawn from 44 patients undergoing primary percutaneous coronary intervention (pPCI) for STEMI. First sample was drawn before loading dose of P2Y12, while the second sample was taken twenty-four hours after pPCI. Data was collected between December 2018 and December 2019. Circulating levels of EPCs were quantified by measurement of surface markers - CD34 and CD133 by flow cytometry. Functional aspects of EPCs were evaluated by measurement of colony forming units (CFUs). EPC colonies were counted using an inverted microscope. The cMTT Cell viability Assay was used to estimate the proliferation of EPCs. Results: There was no significant difference in the number of CFUs (1.1 vs 0.7, p=0.17) or levels of both CD34 (1.26 vs 1.04, p=0.52) and CD133 (1.32 vs 0.97, p=0.53), between the two groups before the administration of P2Y12 inhibitors. In contrast, levels of both CD34 (4.62 vs 1.71, p<0.01) and CD133 (4.3 vs 1.52, p<0.01) were significantly higher in the Ticagrelor group, twenty-four hours following pPCI. Conclusion: Among STEMI patients, those treated with Ticagrelor demonstrated higher levels of EPCs as compared with Prasugrel, twenty-four hours following pPCI. This may indicate a presumed important pathophysiological effect of one medication over the other, and potential opportunities for improved therapeutics among patients with STEMI.