To graft or not to graft? Do coronary artery characteristics influence early outcomes of coronary artery bypass surgery? Analysis of coronary anastomoses of 5171 patients.

Objective: Small coronary size and extensive atherosclerosis pose operative challenges during coronary artery bypass grafting. We investigated the influence of coronary characteristics on early operative outcome.

Methods: Prospectively collected data for 5171 patients undergoing first-time coronary artery bypass grafting from April 1, 1999, to December 31, 2007, were analyzed. Coronary diameter estimated or probe-gauged intraoperatively was regarded as small if 1.25 mm or less. Coronary atherosclerosis was graded as none/mild or moderate/severe. Their influence on postoperative major adverse cardiac events, myocardial infarction or reintervention for graft failure, post-cardiotomy shock, and operative mortality, was investigated.

Results: Of 14,019 coronary anastomoses, 4417 coronaries (31.5%) were small and 5895 coronaries (43.4%) had moderate/severe atherosclerosis. All grafted coronaries were small in 1091 patients (21.1%). Left anterior descending, circumflex, and right coronary arteries received grafts in 94.8% of patients (n = 4903), 74.3% of patients (n = 3842), and 72.5% of patients (n = 3751), with corresponding rates of 31.7%, 31.7%, and 32.6% for small-caliber arteries, 44.4%, 33.3%, and 47.2% for moderate/severe atherosclerosis, and 0.6%, 0.5%, and 3.4% for endarterectomy. Postoperative major adverse cardiac events occurred in 236 patients (4.6%). There was no clear evidence that small caliber of half or more distal anastomoses in a patient (odds ratio, 1.36; 95% confidence interval, 0.97-1.94; P = .07) increased the risk of a major adverse cardiac event, but incomplete revascularization (odds ratio, 1.87; 95% confidence interval, 1.03-3.39; P = .04) and moderate/severe atherosclerosis of the left anterior descending artery (odds ratio 1.37; 95% confidence interval, 1.01-1.87; P = .04) did increase the risk.

Conclusion: Grafting small coronaries did not significantly increase the risk of an early postoperative major adverse cardiac event, but incomplete revascularization did increase the risk. Our findings support grafting small coronaries when technically feasible to prevent incomplete revascularization.