Drug-eluting stents: clinical experiences and perspectives

Drug-eluting stents (DES) have entered the arena and are about to changed the landscape of Interventional Cardiology. Today, the number of agents under preclinical and clinical investigation has increased considerably, including drugs such as Paclitaxel, Sirolimus, Tacrolimus, Everolimus, Dexamethasone, etc. Several studies have recently been published or are still ongoing evaluating different stent designs with respect to their safety and efficacy in treatment of coronary lesions. The SCORE trial (Paclitaxel) revealed a significant reduction in restenosis at follow-up (FU) in the drug-eluting stent group (6.4% vs 36.9% control group), attributable to decreased intimal proliferation. However, stentthromboses and myocardial infarctions, due to both stent design and high drug dosages, were observed causing a MACE rate of 10.2% in the DES group. Confirming the beneficial reduction of stent renarrowing using a local drug-eluting device, the rate of restenosis in the TAXUS-I trial (Paclitaxel) was 0% at follow-up in patients with DES vs 10% in patients with bare stents. Differences in MACE were not observed, which underlined the potential impact of an optimal stent design. First clinical experiences with a Sirolimus-coated stent (FIM trial) demonstrated again a profound inhibition of neointimal ingrowth at 4-month follow-up. The RAVEL trial, the first multicenter trial evaluating the Sirolimus stent and the largest DES study published so far, confirmed the FIM findings with a rate of restenosis in the DES group of 0% at 6 month FU. At 12 month FU, the beneficial impact on neointimal growth inhibition was persistent. The pivotal study SIRIUS is addressed to evaluate this stent design more extensively. However, given all the results being available today, local application of anti-proliferative agents delivered by coronary stents is one of the most promising techniques in treatment of coronary lesions. Nevertheless, we need more trials and an agreement of definitions in order to evaluate this treatment concept and eliminate unwanted side-effects.