Revascularization of chronic total occlusion of coronary artery: a challenge and an opportunity.

ABSTRACT

Remarkable progress has been achieved in the percutaneous management of coronary artery disease over the last decade. In the early 1990s, the primary success rate with the use of bare metal stents was 86-88% and the restenosis rate, 30%-40%. Over the last decade, drug-eluting stents have been developed to check the high rates of in-stent restenosis following percutaneous coronary revascularization. In randomized trials, polymer-coated sirolimus- and paclitaxel-eluting stents, when compared to bare metal stents, have been shown to markedly reduce the incidence of both angiographic restenosis and repeat revascularization. The effectiveness of drug-eluting stents in the prevention of restenosis has been confirmed in patients with stable stenotic lesions, as well as many patients with specific lesions, such as those with in-stent restenosis and acute myocardial infarction. Currently, the primary success rate using drugeluting stents has risen to over 95% and the restenosis rate to less than 10%. In spite of remarkable technological advances and improved outcomes with percutaneous coronary revascularization, chronic total occlusions of the coronary artery remain a source of procedural frustration and clinical uncertainty. With continued developments in catheterbased technologies, there is an opportunity to achieve recanalization of chronic total occlusions with drug-eluting stents; this subset of patients is now recognized as the last formidable barrier to the success of percutaneous revascularization. This review provides an overview of the pathophysiology of chronic total occlusions and the clinical outcomes associated with chronic total occlusion revascularization, and provides future directions for clinical investigation.