Evolving standard in the treatment of coronary artery disease. Drug-eluting stents.

Coronary stent implantation is the predominant method of percutaneous coronary interventions (PCI). This is to be attributed to the ease of use beside the better short and long term clinical outcome as compared to balloon angioplasty. Nevertheless, improvements in operator skill and stent technology together with better use of adjunctive pharmacological therapy have contributed to the improvement in clinical outcome. However, the main limitation of coronary stenting is still represented by in-stent restenosis (ISR) with an estimated rate of 17-32%. Thus, compared to coronary bypass surgery, the major adverse cardiac events following stent implantation are still higher and mainly represented by the need for re-intervention. The advent of drug eluting stents (DES) has led the experts to predict that with DES there will be little or no difference between PCI and coronary bypass surgery in terms of long-term outcome leading to a further expansion of indications. The clinical trial programs of the 2 available DES for clinical use (sirolimus-eluting stent, SES - Cypher and paclitaxol-eluting stent - Taxus) have been able to demonstrate the safety and clinical efficacy of both. Nevertheless, off-label use in patients on high risk for restenosis confirmed these data. At least for SES as was demonstrated by 2 "real world" registries. Thus, the introduction of DES represents a remarkable evolution for new standards in coronary artery disease treatment and offers hope to those patients considered to be "high risk" such as diabetics, patients with ISR, diffuse disease in whom surgery was previously the only therapeutic option. This paper will discuss the main results of the clinical trial programs of the DES (mentioned above) available for clinical use in the present time and analyze technical and procedural aspects which could affect long term outcome.