CTO common after CABG

In patients with coronary disease who have previously undergone CABG, chronic total occlusions occur frequently and present significant challenges for physicians performing PCI, a speaker said at the Chronic Total Occlusions Summit.

During his presentation, Stéphane Rinfret, MD, SM, chief of interventional cardiology at McGill University in Montreal, said registry data from Canada show that about 18% of patients with coronary disease develop CTOs. This percentage, however, increases to 54% among patients who had prior CABG, with approximately 50% of these patients having at least two CTOs.

In a study that evaluated long-term follow-up after CABG with radial artery or saphenous vein graft, more patients developed at least one new native coronary artery CTO, with more occurring in the right coronary artery. The study also indicated that these patients generally had more severe lesions before CABG, Rinfret noted. He also cited another analysis showing that patients who had previous CABG fared better with native PCI vs. saphenous vein graft PCI.

However, treating native coronary disease is difficult in patients who had previous CABG, Rinfret said. One potential problem is that patients who have previously undergone CABG have different characteristics than those who have not. In one study, he and colleagues found that patients who had previous CABG tended to be older, more often had diabetes, presented with unstable condition and had more complex CTOs.

In treatment of patients who had previous CABG, the retrograde approach to CTO PCI and dissection re-entry were also more common, according to Rinfret, and these patients received more contrast and procedures were typically longer. The findings also showed that patients who had previous CABG had more in-hospital complications, although the finding was not statistically significant, and had a higher risk for death, stroke and MI than patients who did not have previous CABG.

Patients who develop CTOs after CABG present technical challenges, according to Rinfret. For example, they have multiple sources of collateral flow, often epicardial, as well as left ventricular dysfunction and are at risk for loculated tamponade. Further, physicians also have to deal with old saphenous vein graft anastomosis, septal branches coming from grafted left anterior descending artery, angulated anastomosis and a distal CTO cap submitted to saphenous vein graft flow.

Rinfret noted, however, that occluded or patent saphenous vein grafts may be useful as retrograde pathways for native CTO PCI and that the hybrid approach allows high success with acceptable complication rates. – by Melissa Foster

Reference:

Rinfret S. CTO PCI in post-CABG patients. Presented at: Chronic Total Occlusion Summit; Feb. 22-24, 2017; New York.

Disclosure: Rinfret reports receiving consultant fees or honoraria from Abbott, Boston Scientific, SoundBite, Terumo and Vascular Solutions.