Case control study of patients with and without restenosis to demonstrate the link between in-stent restenosis and an excessive skin healing. Patients will undergo skin biopsy and blood sample tests to search for a relationship between both processes and for the identification of biomarkers and therapeutic targets.

Restenosis represents an excessive response to the coronary stent. On the other hand, skin healing with keloid formation is also an excessive repair response. There is evidence that both processes may be related because they share mechanisms mediated by inflammatory response. The purpose is to demonstrate the correlation between them for the identification of biomarkers and therapeutic targets.

The project is a case-control study with 2 groups of patients: a control group of 40 patients with ≥1 bare metal stent which in a posterior catheterization performed by clinical follow-up had no restenosis and a group of 20 patients with ≥1 bare metal stent and 20 patients with ≥1 drug eluting stent which had restenosis in a posterior catheterization also performed by clinical follow-up.

A skin biopsy will be performed at the baseline visit from which primary cell cultures of fibroblasts and keratinocytes will be obtained. Four to six weeks later a second biopsy on the scar will be performed and analyzed anatomically and pathologically. In addition, at the initial visit, blood samples will be drawn for analysis of inflammation markers, RNA and proteins. Studies can be performed at 3 levels:

1. The similarities and differences in cutaneous healing of patients with and without restenosis will be studied in the samples from the second biopsy.
2. With the cell culture from the first biopsy, the investigators will analyze the response of cutaneous cells to antiproliferative drugs and the potential advantage of vitamin D in inhibiting restenosis.
3. With the blood samples the investigators will analyze inflammatory factors, RNA and proteins that can predict these processes and that, in addition, can become potential therapeutic targets which might reduce the rate of restenosis.

Inclusion Criteria:

• Patients with previous coronary stent implantation and a posterior catheterization performed > 8 months after the index procedure due to clinical follow-up (those ones with bare metal stents without restenosis will be included in the group of controls and those with restenosis will be included in the group of cases, 20 with bare metal and 20 with drug eluting stents).
• Age 18-75 years.

Exclusion Criteria:

• Patients on chronic anti-inflammatory treatment, including corticosteroids.
• Patients with previous or current history of malignancy or any other disease mediated by inflammation.

Patients with bare metal stents without restenosis will be included in the group of controls and those with restenosis will be included in the group of cases, 20 with bare metal and 20 with drug eluting stents).