Erythropoietin improves myocardial function and enhances re-endothelialisation. 
Aim of this study was to analyse progenitor cell mobilisation and restenosis in 
patients from the Regeneration of Vital Myocardium in ST-Segment Elevation 
Myocardial Infarction by Erythropoietin (REVIVAL-3) study. Patients with STEMI 
undergoing percutaneous coronary intervention (PCI) were randomly assigned to 
Epoetin beta (EPO) (n=68) or placebo (n=70). Drug-eluting stents (DES) were 
utilised in 93% of patients receiving EPO and in 95% of patients receiving 
placebo (p=0.83). Serial venous blood samples were drawn; CD133+ progenitor 
cells were quantified by four-colour flow cytometry and cytokines interleukin 
(IL)-1β, IL-6, IL-8, IL-10, IL-12 and tumour necrosis factor (TNF) alpha were 
analysed by cytometric bead array. Forty-eight hours after PCI a significant 
increase in CD133+ progenitor cells was observed in the EPO group. Yet, no 
differences in plasma cytokines were found. Quantitative coronary angiography 
after six months revealed an increase in segment diameter stenosis in the EPO 
group (32 ± 19% vs. 26 ± 14%, p=0.046). However, this increase in neointima 
generation was not associated with progenitor cell mobilisation. EPO in patients 
with STEMI treated with PCI is associated with an increase in diameter stenosis 
that is not associated with circulating progenitor cells.