This is a prospective cohort, one center. twenty patients who will undergo percutaneous stent implantation with everolimus eluting stent will be include. The primary endpoint was the correlation between the change (baseline vs. 1 week) in the number of circulating endothelial progenitor cells and in cell functionality following an everolimus eluting stent implantation with the grade of neointimal hyperplasia measured by optical coherence tomography

For the purpose of the study, flow cytometry analyses will be performed before intervention, at 1 week, 1 month and 9 months. In addition, cell functionality analyses will be performed by quantification of colony forming units, aldehidrodehidrogenase activity, cell proliferation by WST-1 and senescence by !-galactosidase enzyme. At 9 months the degree of neointimal proliferation will be measured by optical coherence tomography . A clinical follow-up will be performed at 1 year. Secondary endpoints include: 1. to correlate the change in the number and cell functionality of circulation progenitor cells following everolimus eluting stent and the injury score analyses measured by optical coherence tomography, and the percentage of non covered struts by optical coherence tomography at 9 months.

2.-. To evaluate the role of other subtypes of cells CD 133+/Kinase Insert Domain Receptor (KDR+), CD 14+, mesenchymal stem cells, endothelial cell markers (VE cadherina, P1H12), integrin expression of Macrophage-1 antigen (MAC-1) and the development of neointimal hyperplasia.

Inclusion Criteria:

• Patients who present stable angina, silent ischemia or unstable angina whenever there is no elevation of markers of myocardial damage above the limit of normality
• Presence of at least one severe coronary stenosis (> 70% by visual analysis), susceptible of percutaneous treatment with stent implantation and an optical coherence Tomography study
• All patients should be taking statins at least 2 months prior to their inclusion in the study.

Exclusion Criteria:

• Age under 18 years and pregnant or fertile age,
• Patients with ST-elevation myocardial infarction or non-ST-elevation acute coronary syndrome with markers of recent myocardial damage (<3 months),
• Patients in whom a drug-eluting stent and a bare stent have been implanted in the same procedure.
• Percutaneous treatment of restenotic lesions or total chronic occlusions.
• The use of stent pre-implantation ablation techniques (rotablator, directional atherectomy).
• Chronic renal insufficiency with serum creatinine greater than or equal to 2.5.
• Coronary revascularization in previous 3 months.
• Severe ventricular dysfunction (<25%).
• Major trauma or surgery in the previous 3 months.
• Previous organ transplantation, active neoplastic process or inflammatory disease, treatment with immunosuppressors.
• Contraindication or allergy to thienopyridines.
• Life expectancy less than one year.

stable angina