Abstract and Introduction
Abstract
Although interventional technology and skills have markedly advanced, percutaneous coronary intervention (PCI) for coronary chronic total occlusion (CTO) lesions remains challenging. Indeed, CTO PCI is technically complex, carries the potential for a relatively high likelihood of failure and acute complications, and requires specifically skilled operators and a demanding use of resources. In addition, controversy persists surrounding appropriate indications for attempting CTO revascularization. Finally, there is a wide uncertainty on the actual benefits achieved with successful CTO recanalization. A growing number of studies have reported procedural results and/or assessed functional effects and long-term clinical outcomes of CTO PCI. We therefore sought to review and critically appraise the evidence base for procedural outcomes and potential clinical benefits of CTO PCI.
Introduction
In a current catheterization laboratory practice, coronary chronic total occlusions (CTOs) have been commonly identified in 18% of patients with no prior coronary artery bypass grafting (CABG) and significant coronary artery disease (>50% stenosis in >1 coronary artery) undergoing nonemergent angiography. Because percutaneous coronary intervention (PCI) success rates with CTOs are less than with nonoccluded lesions, CTOs impact decision making in different clinical scenarios. Significant improvements in technique and development of novel dedicated PCI strategies have recently emerged. In parallel, industry has been investing large efforts in advancing device and wire technologies. These technical advancements notwithstanding, percutaneous treatment of CTOs remains challenging, and presently, most of these lesions are medically or surgically managed, as shown in a recent large multicenter CTO registry. The relatively low rate of CTO PCI may be attributable to several factors including PCI technical complexity, potential for a relatively high likelihood of failure and acute complications, requirement of specifically skilled operators, and a costly and demanding use of resources. Regardless of the revascularization strategy, surgical or percutaneous, a relevant issue in approaching CTOs includes uncertainties surrounding the actual benefits achieved with successful recanalization. Finally, although current guidelines state that PCI for CTO is reasonable (class IIa) in patients with appropriate clinical indications, there is a limited understanding of these latter, hampering decision making and selection of patient subsets who will likely benefit from successful CTO recanalization. A growing number of studies reporting procedural results and/or assessing functional effects and long-term clinical outcomes of CTO PCI are now available. We therefore sought to review and critically appraise the evidence base for procedural outcomes and potential clinical benefits of CTO PCI.