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

Abstract

Background: 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). Methods: 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. Results: 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. Conclusions: 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.

Why and how to achieve total arterial revascularisation in coronary surgery

“…The theoretical framework is that, if one arterial graft is better than SVG, then two or even three arterial grafts should have incrementally greater survival, and this contention is supported by multiple publications [38][39][40] . In our own national database analysis, we conducted a series of large-scale propensity score matches using 17 variables.…”

“…The relationship between graft failure and reduced survival has a plausible mechanism and therefore it is suggested that the conduit of most interest is the SVG rather than the arterial conduits [37,38,40,45,46] . It would be logical, therefore, that the number of SVG grafts has greater effect on survival than the number of arterial grafts.…”

Transatlantic editorial: The use of multiple arterial grafts for coronary revascularization in Europe and North America

“…34 As discussed, although a large body of observational data suggests that a second arterial conduit is associated with improved survival, graft patency, and freedom from reintervention, the findings of randomized studies have been equivocal. [4][5][6]17,18,[20][21][22][23][24][25][26][27][28]31 For those surgeons convinced by the available evidencebase, an important factor limiting use of MAG may be technical expertise. The extent of and reason for this gap in practice are not apparent from simply analyzing surgeon case-volume and revascularization strategy.…”

Commentary: Radial artery and bilateral mammary arteries in coronary artery bypass grafting: How much is too much?

“…Findings from this study are consistent with recent work from our group showing no difference in late mortality in 2789 propensity score matched pairs comparing 3 arteries vs 2 arteries (HR: 1.08 [95% CI, 0.90-1.29], mean/ maximum follow-up 4.2/8.5 years). 10 On the contrary, a meta-analysis of 8 propensity score-matched observational studies suggests that 3 arterial grafts were associated with a lower risk of late death (HR, 0.80; 95% CI, 0.75-0.87) 11 compared with use of 2 arteries. Similarly, a metaanalysis of randomized clinical trials and observational studies suggested that late mortality was modestly reduced with total arterial revascularization compared with CABG with 2 arteries (incident rate ratio, 0.85; 95% CI, 0.73-0.99).…”