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Document Details :
Title: Drug-eluting stents: a new treatment in the prevention of restenosis
Subtitle: Part I: experimental studies
Author(s): SALU, Koen J. , BOSMANS, Johan M. , BULT, Hidde , VRINTS, Chris J.
Journal: Acta Cardiologica
Volume: 59 Issue: 1 Date: February 2004
Over the past decade, the use of endoluminal metallic stents has become common practice during percutaneous coronary intervention (PCI), especially after clinical trials showed evidence of decreased restenosis rates when compared with balloon angioplasty alone. Although stents significantly reduce restenosis when compared with balloon angioplasty, due to elimination of acute recoil and chronic negative remodelling, restenosis rates in patients who receive stents are still 20-40% at 6 months due to an exaggerated neointimal hyperplastic vascular response.
In-stent restenosis (ISR) due to intimal hyperplasia, results from a complex cellular cascade. First, platelets are activated, form thrombi and release their granule contents. Together with cytokines and growth factors released from injured cells in the vessel wall,they recruit inflammatory cells and stimulate smooth muscle cell (SMC) migration and proliferation. Finally, SMCs start to form extracellular matrix, all resulting in an exaggerated intimal response, maintained by a chronic inflammatory process. Therefore, the recent concept of using stents coated with agents that could potentially inhibit this neointimal hyperplasia, the last hurdle in PCI, has emerged. These agents include anti-thrombotic, anti-inflammatory and anti-mitotic agents.This 2-part article reviews both the available animal and human studies. Part I will discuss the rationale and the technology of drug-eluting stents and also the experimental animal studies performed with these stents. Part II will then summarize the available data of both non-randomised clinical studies and the larger randomised clinical trials with drug-eluting stents as well as the studies in progress. Some critical remarks that still emerge after the introduction oft hese new devices in clinical practice will be discussed.