Progress in Predicting Chronic Total Occlusion Recanalization.

SEE PAGE 1 G iven its historically low procedural success rate, chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has long been considered the Achilles’ heel of percutaneous revascularization. Recent years, however, have witnessed significant progress in the field. Indeed, the adoption of novel strategies coupled with dedication and perseverance of pioneering operators has increased CTO PCI success rates in expert hands from 50% to 90% (1). Techniques that expanded recanalization options, including antegrade and retrograde subintimal tracking, that were originally mastered by Japanese interventionalists have been adopted and streamlined in North America. Despite these advances, PCI continues to be an underused treatment option for CTO lesions (1). There are 3 main reasons for this. First, the indications for CTO PCI remain controversial. On the one hand is the argument that a total occlusion (particularly with collaterals) is a relatively stable situation, whereas on the other hand, observational data suggest that patients with nonrevascularized CTOs have worse outcome than those with non-CTO disease or with revascularized CTOs, possibly due to the “double jeopardy” of territory if the collateral donor vessel develops an occlusion (2). Presently, CTO PCI carries a lower Appropriate Use Criteria score than non-CTO PCI for similar clinical and angiographic scenarios (3). The second reason for the underuse of CTO PCI relates to concerns about procedural and radiation safety, and increased resource utilization. The third reason is the low procedural success rates among non-expert CTOoperators