First generation drug eluting stents (DES) are now a decade old, and several second generation DES have now entered the market. The Xience V or Promus everolimus-eluting stent has been accruing impressive data to suggest improved outcomes for restenosis and major adverse cardiac events, coupled with significantly improved deliverability. The Endeavour zotarolimus eluting stent however has fared less well, with some data suggesting that its use is associated with increased angiographic restenosis as compared to the first generation DES and also increased MI and stent thrombosis. To address these issues the Endeavour Resolute stent has been developed where the stent is coated with a polymer that is a mixture of a hydrophilic biocompatible component that faces the endoluminal surface and a hydrophobic component that is attached to the metal stent surface and serves as a drug reservoir, enabling sustained release of zotarolimus. With early promising data that the Resolute stent remedied many of the perceived short-comings of previous stetnts, the authors conducted a multicenter, noninferiority trial with minimal exclusion criteria, attempting to recruit “real-world” patients. While these individuals make up the bulk of day-to-day practice, they would ordinarily be excluded from trials as their treatment indication would be considered “off-label”.
2292 patients were randomly assigned to undergo treatment with either the new zotarolimus or everolimus stents and twenty percent of patients were randomly selected for repeat angiography at 13 months. The primary end point was target-lesion failure, defined as a composite of death from cardiac causes, any myocardial infarction, or clinically indicated target-lesion revascularization within 12 months. The secondary angiographic end point was the extent of in-stent stenosis at 13 months. At least one off-label criterion for stent placement was present in 66% of patients. The zotarolimus-eluting stent was found to be noninferior to the everolimus-eluting stent with respect to the primary end point, which occurred in 8.2% and 8.3% of patients, respectively (P<0.001 for noninferiority). There were no significant between-group differences in the rate of death from cardiac causes, any myocardial infarction, or revascularization. The rate of stent thrombosis was 2.3% in the zotarolimus-stent group and 1.5% in the everolimus-stent group (P=0.17). The zotarolimus-eluting stent was also noninferior regarding the degree of in-stent stenosis (21.65+/-14.42% for zotarolimus vs. 19.76+/-14.64% for everolimus, P=0.04 for noninferiority) with in-stent late lumen loss being 0.27+/-0.43 mm in the zotarolimus-stent group versus 0.19+/-0.40 mm in the everolimus group (P=0.08).
At 13 months, a new-generation zotarolimus-eluting stent was found to be noninferior to an everolimus-eluting stent in a “real-world” setting.
• Serruys PW, Silber S, Garg S, van Geuns RJ, Richardt G, Buszman PE, Kelbæk H, van Boven AJ, Hofma SH, Linke A, Klauss V, Wijns W, Macaya C, Garot P, Dimario C, Manoharan G, Kornowski R, Ischinger T, Bartorelli A, Ronden J, Bressers M, Gobbens P, Negoita M, van Leeuwen F, Windecker S. Comparison of Zotarolimus-Eluting and Everolimus-Eluting Coronary Stents. N Engl J Med. 2010 Jun 16. [Epub ahead of print]