Multiple Versus Single Arterial Coronary Bypass Graft Surgery for Multivessel Disease

Despite recent guideline statements, there is still wide practice variation in the use of multiple arterial grafts (MAGs) versus single arterial grafts (SAGs) for patients with multivessel disease undergoing coronary artery bypass graft surgery. This may be related to differences in findings between observational and randomized controlled studies.

This study sought to compare intermediate-term MAG and SAG outcomes with enhanced matching to reduce selection bias.

New York's cardiac registry identified 63,402 multivessel disease patients undergoing coronary artery bypass graft surgery between January 1, 2005, and December 31, 2014, to compare outcomes (median follow-up 6.5 years) for patients receiving SAGs and MAGs. SAG and MAG patients were propensity matched using 38 baseline characteristics to reduce selection bias. The primary endpoint was mortality, and secondary endpoints included repeat revascularization and a composite endpoint of mortality, acute myocardial infarction, and stroke.

Before matching, 20% of procedures employed MAG. At 1 year, there was no mortality difference between matched MAG and SAG patients (2.4% vs. 2.2%, adjusted hazard ratio [AHR]: 1.11; 95% confidence interval [CI]: 0.93 to 1.32). At 7 years, MAG patients had lower mortality (12.7% vs. 14.3%, AHR: 0.86; 95% CI: 0.79 to 0.93), a lower composite outcome (20.2% vs. 22.8%, AHR: 0.88; 95% CI: 0.83 to 0.93), and a lower repeat revascularization rate (11.7% vs. 14.6%, AHR: 0.80; 95% CI: 0.74 to 0.87). At 7 years, the subgroups for which MAG did not have a lower mortality rate included patients with off-pump surgery, 2-vessel disease with right coronary artery disease, recent acute myocardial infarction, renal dysfunction, and patient ≥70 years of age.

Mortality and the composite outcome were similar between MAG and SAG patients at 1 year, but lower for MAG after 7 years. Patients of higher volume MAG surgeons experienced lower MAG mortality.