ABSTRACT
Introduction Although coronary stenting can reduce the rate of angiographic restenosis and improve clinical outcome in some lesion subsets, it is still hampered by early (sub)acute thrombosis and late restenosis. Systematically administered pharmacological agents evaluated for reducing neointimal hyperplasia have failed, most probably because of low active drug concentration at the target site.1 The development of techniques to reliably provide sustained high drug concentration at the target site is desirable. This has led to the development of strategies designed for local drug delivery. A number of strategies to achieve high drug concentrations at the target site without systemic side-effects have been evaluated in experimental and in clinical conditions. Endovascular stents may be the ideal platform for local drug delivery, since they can serve as a reservoir for local drug administration. Compared to local drug delivery catheters, the potential advantage of drug-eluting stents is the immediate tissue contact and the more prolonged drug release. Until now, most drugeluting stents have focused on the two major remaining problems of stenting: thrombosis and neointimal hyperplasia. Synthetic or biological polymers can be used as matrices for drug incorporation and elution. Several studies have demonstrated that polymer-coated stents can be a well-tolerated and effective means of providing sustained, site-specific drug delivery to the coronary artery wall.
