Late Incomplete Stent Apposition Evaluation II: Comparison Between Polimer-based and No-polimer Stent System. IVUS Based Study

Vascular effects evaluation after non-polimeric and polimeric paclitaxel stent implantation.In particular the investigators will use Taxus )as a polimeric stent)and Axxion (as a non-polimeirc)stent system. The investigators will look at late stent malapposition by means of intracoronary ultrasound imaging technique (IVUS) at baseline and 9 months follow-up. The investigators sought to compare the two stent types with the same drug to verify the polimer role. The polimer itself seems to provoke inflammation and hypersensibility if the arterial wall and it seems to be the base of a process of positive remodeling found at drug eluting stent implantation site. This positive remodeling is the mechanism producing late stent malapposition which on its turn can determine stent thrombosis, as demonstrated by pathological studies. At the same time the investigators will study the incidence of clinical events like myocardial infarction, stent thrombosis, TLR and death along with the incidence of angiographic restenosis at 2 years follow up.