New developments in drug-eluting stents

Abstract

Although the use of balloon catheters or stents for the treatment of coronary artery lesions shows good short-term results, long-term prognosis due to the occurrence of restenosis in 20%-30% of patients is less promising. Thus new techniques and mechanical improvements to balloons and stents are always necessary in order to achieve the best possible results from percutaneous coronary intervention. Drug-eluting stents (DES) have improved the principles of bare metal stents (BMS) by neointimal growth inhibition due to local drug release. DES can significantly reduce the incidence of in-stent restenosis. These benefits and lower costs compared to surgical treatment make the DES a more attractive alternative for the treatment of coronary heart disease. Currently, the CYPHER Sirolimus-eluting stent (SES) by Cordis (approved by the FDA on 24th April 2003), the TAXUS Express and the LIBERTE Paclitaxel-eluting stent (PES) by Boston Scientific (approved by the FDA on 4th March 2004 and October 10, 2008), the Endeavor Zotarolimus-eluting stent (ZES) by Medtronic (approved by the FDA on 1st February 2008) and the Xience V Everolimus-eluting stent (EES) by Abbott Vascular (approved by the FDA on 2nd July 2008) are approved in the US. Following approval of the Cypher and Taxus stents, the clinical data indicated a slightly higher incidence of stent thrombosis (ST) as compared to the pure BMS after implantation. The present article discusses the main clinical trials and design developments in DES currently available and takes a prospective look at future technologies in the field of DES.