• The binary restenosis rate (defined as restenosis >50% on follow-up angiography) at six-month angiography
  

• A composite of: Major adverse cardiac events (death, myocardial infarction, and ischemia driven target lesion revascularization)
  
• Target vessel failure (defined as a composite of death from cardiac causes, myocardial infarction, and ischemia-driven target-vessel revascularization) at 6 month
  
• In-stent and in-segment minimal lumen diameter
  
• Percentage in-stent and in-segment diameter stenosis
  
• In-stent and in-segment late luminal loss at six months follow-up
  

Since data from the 2 landmark studies, the BENESTENT and STRESS studies, showed that coronary stenting significantly decreases restenosis as compared with conventional balloon angioplasty, this treatment modality has shown to be superior in an increasing number of indications. Percutaneous coronary intervention of chronic total occlusions (CTO), however, is still limited by high restenosis rates. Although coronary stenting using bare metal stents significantly decreases restenosis in CTO, restenosis rates still reach 32% to 55%.

In 200 patients with CTO randomized in the PRISON I study, we demonstrated a restenosis rate of 22% after bare metal stent implantation as compared with 33% after conventional balloon angioplasty. During the past few years, sirolimus (rapamycin), a cytostatic macrocyclic lactone with anti-inflammatory and antiproliferative properties, delivered from a polymer-encapsulated stent was shown to almost eliminate the risk of restenosis in selected groups of patients.

In this prospective, randomized, single-blind trial we enrolled 200 patients with chronic total occlusions: 100 were randomly assigned to receive bare metal BxVelocity™ stents, and 100 to receive sirolimus-eluting Cypher™ stents. The primary endpoint was angiographic binary restenosis rate at six months follow-up. Secondary endpoints were a composite of major adverse cardiac events, target vessel failure, in-stent and in-segment minimal lumen diameter, percentage diameter stenosis, and late luminal loss at six months follow-up. Clinical long-term follow-up will performed up till 24 months