The development, clinical validation, and widespread use of drug-eluting stents have revolutionized the treatment of patients with coronary artery disease. Large scale, prospective, multicenter double-blind randomized trials have provided strong evidence that sirolimus-eluting stents, paclitaxel-eluting stents, and zotarolimus-eluting stents significantly reduce angiographic restenosis and enhance event-free survival compared with bare-metal stents after implantation in native coronary arteries1. However, higher rates of late and very late stent thrombosis with SES and PES, likely due to delayed and incomplete endothelialization compared with BMS, have raised safety concerns with DES as a class. Therefore, alongside clinical investigations, histopathological evaluations were conducted on the coronary arteries of patients who died after DES implantation to examine the healing status of the vessel. The evidence obtained suggested that the polymer components used to carry the drug in the first generation of DES may be associated with a local inflammatory response, associated with localized hypersensitivity and eosinophil infiltration, with consequent alteration of the vessel wall and delay in the formation of the endothelium. Because specific stent design and/or polymer features may impact DES performance, numerous studies have focused on the comparative assessment of various DES, with conflicting results.

The clinical need thus exists for enhanced stent designs which offer improved safety and efficacy profiles compared to the earlier stent platforms.

new technologies have been developed which have led to the creation of devices with delivery systems based on the use of more biocompatible or bioabsorbable polymers and cytostatic drugs similar to sirolimus. The clinical data obtained with this second generation have demonstrated, in all devices tested, no less efficacy than first-generation DES, and a better safety profile, although not statistically significant.Concerning the most widely used second generation DES,after a small first-in-man trial, its safety and efficacy was further studied in larger randomized trials on patients with non-complex lesions in which EES was compared to PES, proving its angiographic superiority and clinical non-inferiority. A step forward, in assessing the clinically significant differences among different DES, was done with a new randomized trial comparing EES versus PES, powered for testing superiority in clinical outcomes and of sufficient magnitude to provide data on patient subgroups, particularly patients with diabetes. At present, a third-generation of DES, developed to minimize the possible side effects related to the presence of the polymer, is being evaluated in humans. To avoid the presence of the polymer on the surface of the device, different platforms are being evaluated: those with a porous surface onto which the pure drug is placed and those with holes closed towards the intraluminal part by a bioabsorbable polymer, onto which the drug is loaded. A third option to avoid the need of polymers has been used in the new CRE8 DES, featuring a polymer free platform with abluminal reservoirs to release the Amphilimus formulation. This device has been tested against Taxus Liberté in a randomized clinical trial, to assess the non-inferiority angiographic efficacy results. The 6month angiographic analysis, demonstrates that the primary study endpoint has been achieved, showing that CRE8 was not inferior to Taxus Liberté in terms of efficacy performances.