Early Experiences and Clinical Implications of Drug-Eluting Stents: Part 1

OBJECTIVE: To review the pathogenesis of in-stent restenosis and the evolution of drug-eluting stents (DES). DATA SOURCES: Using the search terms sirolimus, paclitaxel, and drug-eluting stents, a literature review was conducted to identify peer-reviewed articles and abstracts in MEDLINE (1966-June 2003). Recent meeting abstracts were accessed through the American Heart Association and the American College of Cardiology Web sites. Citations from available articles were also reviewed for additional references. STUDY SELECTION AND DATA EXTRACTION: Published reviews and studies showing the effects of in-stent restenosis and drug-coated and -eluting stents were evaluated and reviewed. DATA SYNTHESIS: Coronary stent implantation is a common form of percutaneous coronary interventions. Approximately 20-30% of patients undergoing stent placement develop restenosis 6 months after the procedure. The primary cause of in-stent restenosis is neointimal proliferation and subsequent accumulation of extracellular matrix, collagen, and macrophages. Eluting stents with an antimitotic agent may reduce the extent of restenosis. Research is ongoing in terms of finding the ideal combination of antimitotic agent, stent, and eluting medium to create the perfect stent. CONCLUSIONS: Research over the last decade has led to a better understanding of the pathogenesis of in-stent restenosis and ways to prevent restenosis. DES are being developed as one of the strategies to prevent restenosis.