Outcomes of Second Arterial Conduits in Patients Undergoing Multivessel Coronary Artery Bypass Graft Surgery

Background: Benefits of multiarterial versus single-arterial coronary bypass grafting (CABG) are debated. Objectives: This study sought to compare long-term survival, morbidity, and graft patency after multiarterial versus single-arterial CABG. Methods: Mandatory clinical registries linked with discharge databases were used to identify baseline and operative characteristics and outcomes of 42,714 patients undergoing CABG from 2005 through 2012. Patients with single-vessel disease, without arterial conduits, or undergoing emergency, reoperative, or concomitant procedures were excluded. Survival, stroke, myocardial infarction, and repeat revascularization rates were compared using Cox modeling, and patients were matched by propensity score. Median follow-up was 7.8 years (interquartile range: 5 to 10 years); last follow-up was December 31, 2016. Results: Of the 26,124 patients, 3,647 (14.0%) underwent multiarterial CABG. Single-arterial CABG patients were older (mean 68 vs. 61 years; p < 0.001), had more comorbidities, and received fewer bypass grafts (3.4 vs. 3.6; p < 0.001). After adjusting for baseline differences, multiarterial CABG was associated with lower 10-year mortality compared with single-arterial CABG in 3,588 propensity-matched pairs (15.1% vs. 17.3%; p = 0.01). Multiarterial CABG was associated with lower 10-year myocardial infarction (hazard ratio: 0.81; 95% confidence interval: 0.69 to 0.95) and lower 10-year reintervention rate (hazard ratio: 0.81; 95% confidence interval: 0.67 to 0.99). Conclusions: In contemporary practice, single-arterial CABG is used in 85% of patients and is associated with increased long-term mortality, myocardial infarction, and reintervention compared with multiarterial CABG. Multiarterial CABG is underused in contemporary surgical revascularization, and targeted referral of younger patients for multiarterial revascularization may address this practice gap.