Impact of coronary total occlusion on graft failure and outcomes of coronary artery bypass grafting.

Objective: The study objective was to assess the impact of chronic total occlusion on long-term graft failure and outcomes in patients who underwent coronary artery bypass grafting.

Methods: We conducted an observational study involving a single-center subgroup of the CORONARY trial. At 6 to 9 years after coronary artery bypass grafting, all alive patients were invited for coronary computed tomography angiography and clinical follow-up. We assessed the association between chronic total occlusion graft and failing graft showing Fitzgibbon type B or O. Risk factors associated with chronic total occlusion graft failure were assessed. The impact of chronic total occlusion on clinical outcomes was analyzed, including death, myocardial infarction, and repeated revascularization.

Results: A total of 349 patients undergoing coronary artery bypass grafting were enrolled between May 2007 and October 2011. Of 301 alive patients at follow-up time (median, 6.8 years; interquartile range, 6.0-8.0 years), repeat coronary computed tomography angiography was performed in 206 patients (68.4%) with 723 grafts (154 chronic total occlusion grafts and 569 nonchronic total occlusion grafts). Chronic total occlusion graft was significantly associated with an increased risk of long-term graft failure after adjustment for patient- and graft-level characteristics (adjusted odds ratio, 2.27; 95% confidence interval, 1.42-3.62; P < .001). Arterial graft, side-to-side anastomosis, higher graft flow, and antiplatelet therapy at discharge were associated with chronic total occlusion graft patency. The presence of 1 or more chronic total occlusions was not significantly associated with long-term composite of death, myocardial infarction, or repeat revascularization (adjusted hazard ratio, 0.91; 95% confidence interval, 0.54-1.51; P = .707).

Conclusions: Chronic total occlusion graft was associated with an increased risk of graft failure. Surgical technique and guideline-directed medical therapy should be noted to improve chronic total occlusion graft patency.