Directional coronary atherectomy: but wait, there's more

Approaches for prevention of restenosis

Coronary artery disease is characterized by a narrowing (stenosis) of the arteries that supply blood to the tissue of the heart. Continued restriction of blood flow manifests itself as angina and ultimately myocardial infarction (heart attack) for the patient. Heart bypass was once the only treatment for this condition, but over the years percutaneous coronary intervention (PCI) has become an increasingly attractive alternative to medical therapy and surgical revascularization for the treatment of coronary artery disease. A vascular stent is a medical device designed to serve as a temporary or permanent internal scaffold, to maintain or increase the lumen of a blood vessel. Metallic coronary stents were first introduced to prevent arterial dissections and to eliminate vessel recoil and intimal hyperplasia associated with PCI. Further advancement in the treatment of coronary artery disease is the development of drug-eluting stents that dramatically reduce the incidence of in-stent restenosis to less than 5%. Local drug delivery offers the advantages of allowing a relatively high local concentration of drug at the treatment site while minimizing systemic toxic effect. This review describes approaches for prevention of restenosis. It focuses on drugs for prevention of restenosis, bare metal stents, and drug-eluting stents. It also describes recent advances in bioresorbable stents. One of the chapters is dedicated to our novel composite bioresorbable drug-eluting fibers, designed to be used as basic elements in drug-eluting stents.

Drug-coated stents

Drug-coated stents appear to be the most promising approach among all interventional strategies to prevent restenosis. These stents both suppress geometric remodeling and inhibit neointimal hyperplasia with a therapeutic agent. Animal studies and recent randomised clinical trials with sirolimus-eluting stents have achieved excellent results in the prevention of restenosis. These stents also have a good safety record and demonstrate a durable clinical benefit for patients at long-term follow-up. This article summarises experimental and clinical experiences with local drug delivery via a stent coating in the prevention of restenosis after coronary angioplasty, outlining the clinician's view of current trends.