Drug eluting stents: developments and current status.

Coronary stenting has revolutionized current perspective of coronary artery disease management. Bare-metal stents (BMS) were introduced in 1994, but long-term results have been shattered by the dual problems of in-stent restenosis (ISR) and stent thrombosis associated with BMS. Though stent thrombosis became much less frequent after the introduction of antiplatelet therapy, restenosis however remained as a significant problem. Intense work on stent development has successfully led to the introduction of drug-eluting stents (DES) in 2002, as an effort to address restenosis problem. First generation DES (sirolimus and paclitaxel eluting) were introduced first and found to be more effective than BMS. The use of first generation DES dealt with the problem of restenosis. But, despite early successes, uncertainty remains on the overall safety, especially for late adverse clinical events such as stent thrombosis. Thus, the second generation (everolimus and zotarolimus eluting) stents were developed and introduced with lower thrombosis rates. Today, in the search for improving the performance of available DES various developments and clinical studies are ongoing. Research and developments is primarily centred on increasing the long-term safety and efficacy of stents.