How DECISION-CTO Can Help Guide the Decision to Perform Chronic Total Occlusion Percutaneous Coronary Intervention

oronary chronic total occlusions (CTOs) are completely occluded coronary arteries without antegrade coronary flow and an estimated duration of at least 3 months. 12][3][4][5] Patients with CTOs in the setting of multivessel complex coronary artery disease are often treated with coronary bypass graft surgery.However, some patients with complex coronary artery disease are not candidates for coronary artery bypass grafting (CABG), refuse CABG, or have already undergone CABG.Some other patients have isolated CTOs or few additional lesions.Should such patients undergo CTO percutaneous coronary intervention (PCI)?This can be a challenging decision to make because CTO PCI has lower success and higher complication rates in comparison with PCI of nonocclusive lesions. 6,7 WHAT IS KNOWNSeveral observational studies and 4 randomized, controlled trials have examined the impact of CTO PCI on clinical outcomes.Earlier studies compared successful versus failed CTO PCI and reported significantly worse early and late outcomes among patients who had failed procedures. 8his comparison is hard to interpret because patients who have failed procedures have worse baseline clinical characteristics, and the failure itself may predispose to subsequent adverse events. 8Observational studies have also compared CTO PCI versus medical therapy and have generally reported better outcomes with CTO PCI, yet the lack of randomization also prevents any definitive conclusions. 1 Four randomized, controlled clinical trials of CTO PCI versus no CTO PCI have been published to date.The EXPLORE trial (Evaluating Xience and Left Ventricular Function in Percutaneous Coronary Intervention on Occlusions After ST-Elevation Myocardial Infarction) randomly assigned 304 patients who underwent primary PCI for acute ST-segment-elevation acute myocardial infarction and had a coexisting noninfarct-related artery CTO to CTO PCI (73% success) versus no CTO PCI.At 4 months, cardiac MRI showed no difference between the 2 groups in left ventricular ejection fraction and left ventricular end-diastolic volume (the primary end points of the study). 9imilarly, the REVASC trial (A Randomized Trial to Assess Regional Left Ventricular Function after Stent Implantation in Chronic Total Occlusion) in patients with a stable coronary artery disease and a CTO randomly assigned 205 patients to CTO PCI and no CTO PCI.At 6 months, cardiac MRI showed no difference between the 2 groups in segmental wall thickening in the CTO territory and regional and global left ventricular function, as well. 10