[Coronary restenosis]

Abstract

Coronary restenosis is the answer of the arterial wall to a mechanical violation through balloon angioplasty, bare-metal (BM) stent implantation or rotational atherectomy through repeated narrowing. It has great clinical and prognostic relevance and occurs in approximately 30% of non-coated stents and in 10% of coated coronary stents. The wound healing process that precedes restenosis includes inflammatory reactions, cellular proliferation and remodeling of the arterial wall, where protein synthesis of the extracellular matrix is initiated. The inflammatory reaction activates platelets, leucocytes and monocytes and stimulates smooth muscle cells. The medications on the drug-eluting stents (rapamycin, paclitaxel, sirolimus, evarolimus and zotarolimus) inhibit cell division, are cytotoxic and only these sustainably influence restenosis. Whether they play a role in neoatherosclerosis needs to be determined. The mechanism of restenosis with implantation of drug-eluting stents is heterogeneous and associated with the deposition of T‑lymphocytes and fibrin. Risk factors for the development of restenosis include mechanical factors, such as incorrect apposition and expansion of stents, inflammation, diabetes mellitus, genetic factors, bypass operations, stent length and stent diameter. The restenosis rate is lower with drug-eluting stents and must be considered differently between the drug-eluting stents. Drug-eluting stents of the latest generation and drug-coated balloons (DCB) showed the best clinical and angiographic results for in-stent restenosis in randomized trials. The BM and older first-generation drug-eluting stents should be avoided. Further randomized studies are needed.

Keywords: Angioplasty; Bare-metal stents; Drug-eluting stents; Endothelium; Neoatherosclerosis.