Coronary Stents: All Those Trials

In the nearly 40 years that have elapsed since the first coronary stent implantation in man, there has been a multitude of trials regarding this procedure. Stents were designed to combat two major weaknesses of balloon angioplasty: a high restenosis rate (>30%) and a 2 to 10% rate of abrupt closure. Early trials by some of the pioneers of the field suggested that stents, by scaffolding the artery, were indeed very successful in treating angioplasty-induced flow-limiting dissections. Findings of the BENESTENT-I (Belgian Netherlands stent trial) and STRESS (Stent Restenosis Study) demonstrated that stents reduced the restenosis rate to <30%. Drug-eluting stents were developed to further reduce the restenosis rates. In the SIRIUS trial (Sirolimus-Eluting Stents versus Standard Stents in Patients with Stenosis in a Native Coronary Artery), when compared with a bare metal stent, a sirolimus-eluting stent reduced significantly the need for revascularization of target lesions. Concerns regarding late and very late stent thrombosis with these first-generation drug-eluting stents led to the development of second-generation stents. Multiple trials have demonstrated very low stent thrombosis rates (<1%) with the latter stents. The promise of bioresorbable stents was dimmed by the findings of the ABSORB II trial (Bioresorbable Everolimus-Eluting Scaffold Versus a Metallic Everolimus-Eluting Stent). The findings of the SYNTAX (Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery) trial suggests that the majority of patients with left main stem and three vessel coronary artery disease are better served by coronary artery bypass surgery rather than angioplasty with drug-eluting stents.