Multiple Arterial Grafting Is Associated With Better Outcomes for Coronary Artery Bypass Grafting Patients

Observational studies have shown better survival in patients undergoing coronary artery bypass grafting (CABG) with 2 arterial grafts compared with 1. However, whether a third arterial graft is associated with incremental benefit remains uncertain. We sought to analyze the outcomes of 3 versus 2 arterial grafts during CABG. As a secondary objective, we compared CABG with 2 or 3 arterial grafts (multiple arterial grafts [MAG]) with CABG using a single arterial graft (SAG).

Retrospective cohort analyses of all patients undergoing primary isolated CABG in Ontario, Canada, from October 2008 to March 2016. Propensity score matching was performed between patients with 3 arterial grafts (3Art group) versus 2 (2Art group). The primary outcome was time to first event of a composite of death, myocardial infarction, stroke, and repeat revascularization (major adverse cardiac and cerebrovascular events). Additional analyses were performed to evaluate the association between MAG versus SAG and long-term outcomes using propensity score matching.

Fifty thousand, two hundred thirty patients underwent isolated CABG during our study period; 3044 (6.1%) and 8253 (16.4%) patients had 3 and 2 arterial grafts, respectively, resulting in 2789 propensity score matching pairs for the primary analyses. Mean and maximum follow-up was 4.2 and 8.5 years, respectively. Radial artery grafting was more common in the 3Art versus 2Art group (79.3% versus 65.6%, P<0.01). In-hospital outcomes were not significantly different, including death (3Art 0.8% versus 2Art 0.5%, P=0.26). Up to 8 years, there were no differences in major adverse cardiac and cerebrovascular events (3Art 27%, 95% confidence interval [CI], 24% to 30% versus 2Art 25%, 95% CI, 22% to 28%; hazard ratio [HR], 1.08, 95% CI, 0.94-1.25), death (HR, 1.08; 95% CI, 0.90-1.29), myocardial infarction (HR, 1.15; 95% CI, 0.87-1.51), stroke (HR, 1.39; 95% CI, 0.95-2.06), or repeat revascularization (HR, 1.04; 95% CI, 0.82-1.32). When evaluating MAG versus SAG, 8629 patient pairs were formed using propensity score matching. At 8 years, cumulative incidences of major adverse cardiac and cerebrovascular events (HR, 0.82, 95% CI, 0.77-0.88), survival (HR, 0.80; 95% CI, 0.73-0.88), repeat revascularization (HR, 0.79; 95% CI, 0.69-0.90), and myocardial infarction (HR, 0.83; 95% CI, 0.72-0.97) were superior in the MAG group.

CABG with 3 arterial grafts was not associated with increased in-hospital death nor with better clinical outcomes at 8-year follow-up, compared with CABG with 2 arterial grafts. MAG was associated with superior outcomes compared with SAG.