Despite remarkable advances in the procedural and clinical outcomes of percutaneous revascularization, chronically occluded coronary arteries remain a formidable challenge and unresolved dilemma in interventional cardiology. Although a TCO is identified in approximately one-third of diagnostic cardiac catheterizations, still an attempted revascularization accounts for less than 8% of all percutaneous coronary interventions (PCI). Such a disparity between their frequency and treatment not only underscores the technical and procedural frustrations associated with these complex lesions, but also the clinical uncertainties regarding clinical benefits with conventional TCO revascularization and the ongoing inadequacies of current PCI methods for sustaining restenosis-free patency following initial success.
Until recently, few clinical investigations have been performed to support clinical benefit of TCO revascularization. In addition to relief of symptomatic ischemia, theoretical advantages have included enhanced left ventricular function, reduced predisposition to arrhythmic events, and improved tolerance of future ischemic events. In the Survival and Ventricular Enlargement (SAVE) trial, persistent occlusion of the infarct-related artery was associated with a relative risk of 1.47 in adjusted 4-year mortality (P=0.04). Since then, a limited number of studies documenting long-term outcomes following intended TCO revascularization have been performed.
This investigational protocol is designed to evaluate the safety and efficacy of the Cypher® sirolimus eluting coronary stent (Cordis Corporation, Miami Lakes, FL) in patients undergoing elective revascularization of nonacute total coronary occlusions (TCO). Specifically, approximately 200 patients will undergo Cypher® sirolimus eluting coronary stent(s) implantation following successful crossing of native total occlusions with a coronary guidewire. The study will be conducted at approximately 17 sites in North America. Patients included in this trial will be scheduled for percutaneous revascularization of a non-acute de novo TCO in a native vessel visually estimated to accommodate a ≥3.0 mm diameter angioplasty balloon. Important exclusion criteria will include recent myocardial infarction (\<72 hours) and any general contraindication to the procedure or scheduled clinical and angiographic follow-up. Patients may also undergo treatment of a non-target vessel lesion simultaneous with the index procedure within certain protocol-specified provisions. All patients will undergo planned angiographic follow-up 6 months following the index procedure to evaluate the primary endpoint of restenosis (\>50% diameter stenosis) within the treated/working length segment compared with results obtained using the same methodology among patients undergoing TCO revascularization with the heparin-coated Palmaz-Schatz coronary stent (Cordis Corporation, Miami Lakes, FL) in the Total Occlusion Study of Canada-1 (TOSCA) (1). Important secondary endpoints include the occurrence of major adverse cardiac events (MACE) and target vessel failure (TVF) at 30 days, 6 months and 12 months post-procedure. In addition, angiographic outcomes of in-stent and segment restenosis within the stent and segment will be examined. Further, patients enrolled in the trial will have clinical follow-up annually to five years.
