The LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) Study randomly assigned 1,707 patients with 2,472 lesions to treatment with either a biolimus-eluting stent with a biodegradable polymer or a sirolimus-eluting stent with a durable polymer. The study involved a broad range of patients for whom a stenting procedure was considered suitable, designed to reflect routine clinical practice.
Nine months after the procedure, the numbers of deaths, heart attacks and repeat interventions required because of renewed blood vessel narrowing were equivalent in both treatment groups (9.2% of patients in the biolimus-eluting stent group and 10.5% of patients in the sirolimus-eluting stent group). In the one in four patients given an angiogram, the degree of blood vessel narrowing at the site of stent implantation was also equivalent in both treatment groups.
The DES is designed to treat narrowing of coronary arteries which is one of the principal causes of coronary artery disease. Once implanted, it uses the strength of its cylindrical mesh wall to keep the artery widened and maintain blood flow, and gradually releases its drug into the surrounding tissues. The role of the drug is to inhibit restenosis, a common problem following stent implantation, whereby excessive tissue forms around the stent and may negate the benefit that it provides. First-generation drug-eluting stents released the drug from a durable polymer, which may be associated with the formation of blood clots (thrombosis) more than a year after implantation. A new generation of DES has therefore been developed, using a polymer which is completely degraded into carbon dioxide and water after 6-9 months leaving only the metal mesh behind, more closely resembling a bare metal stent.
"The results from LEADERS are significant, as they demonstrate for the first time that a drug-eluting stent with a biodegradable polymer is just as safe and effective as a conventional drug-eluting stent with a durable polymer, under conditions which resemble those of routine clinical practice", commented LEADERS Principle Investigator Professor Stephan Windecker, University Hospital, Bern, Switzerland. "The next stage will be to investigate whether a biodegradable polymer leads to a lower risk of stent thrombosis in the longer term".