UPDATE ON THE TREATMENT OF THE CHRONIC TOTAL OCCLUSION
Barry Uretsky, M.D., University of Arkansas for Medical Sciences, Little Rock, AR, USA
A key goal in treating obstructive coronary disease is complete revascularization (CR). Multiple observational and registry studies have suggested the value of CR in maximizing survival, minimizing long-term adverse cardiac events, and improving the quality of life. The primary challenge to providing CR with percutaneous intervention (PCI) is treatment of the chronic total occlusion (CTO). Because of the technical challenges, the CTO is often ignored in PCI treatment citing the presence of collaterals filling the region and suggesting that the CTO is a rather “benign” lesion. The idea that collaterals adequately perfuse the myocardium in the CTO territory is a myth; that area is, in fact, a chronically ischemic zone and may account for the worsened outcome of CTO patients compared with matched non-CTO CAD patients. CTO PCI should align with guidelines and appropriate use criteria for management of the non-CTO lesion, governed by the same criteria, i.e. the extent of symptoms and ischemia and the adequacy of medical therapy. Available data have shown that revascularization with PCI of a CTO can improve symptoms, decrease the need for bypass surgery and improve ventricular function and may improve survival. Newer techniques have improved recanalization rates from the relatively poor 60-70% range as reported in large registries to the current 90% range in centers of excellence. These techniques include the antegrade dissection-re-entry technique with dedicated tools including the CrossBoss catheter, Sting-Ray balloon, and Sting-Ray re-entry wire and retrograde techniques, both intra-luminal and dissection re-entry. Currently no randomized trials have demonstrated that CTO PCI is more effective than medical therapy or bypass surgery in multivessel disease but such trials are ongoing and should provide increased clarity in decision-making.