Why Don’t We Kill 2 Birds with 1 Stone?

Why Don't We Kill 2 Birds with 1 Stone? Less Adverse Cardiac Events and Improved Survival With Multiarterial Coronary Artery Bypass GraftingArticle, see p 1698 I n this issue of Circulation, Goldstone and colleagues 1 report the early and midterm outcomes of more than 59 000 patients who underwent primary isolated multivessel coronary artery bypass grafting (CABG) at 126 nonfederal hospitals in California from 2006 to 2011.They found that after propensity matching, receipt of a second arterial conduit was associated with significantly lower all-cause mortality, myocardial infarction, and coronary reintervention at a median follow-up of more than 5 years.It is interesting to note that compared with radial artery (RA) grafting, right internal thoracic artery (RITA) grafting did not confer a survival or cardiovascular advantage, but was associated with increased risk of sternal wound infection.During the study period, use of a second arterial conduit decreased from 10.7% to 9.1%, mirroring a national trend reported by the Society of Thoracic Surgeons Adult Cardiac Surgery Database (11.6% in 2000-2009 versus 6.7% in 2010-2013). 2 Notably, 30% of cardiac surgeons in California did not use a second arterial graft for the duration of the study.So why is there a reluctance to use multiple arterial grafts in multivessel CABG despite the potential benefit?As for the 70% of California's surgeons who use 2 arteries, why do they do so only in a small percentage of patients?The answers to those questions are complex but not elusive.Barriers to multiarterial grafting are diverse, ranging from perceptions about available scientific evidence, to surgical expertise, to health economics and more (Table ).Starting with the scientific evidence, the California study is the largest study to date and an important addition to other large observational studies demonstrating the real-world benefits of multiarterial grafting.[3][4][5] Clinical practice guidelines encourage multiarterial grafting, 2 but the lingering argument for not embracing multiarterial grafting is lack of evidence derived from randomized trials.Ironically, though, the 1986 landmark study from Cleveland Clinic 6 that set the standard of using at least 1 internal thoracic artery in CABG was an observational study that was never corroborated by multicenter randomized trials.The incremental survival benefit of multiarterial grafting over single internal thoracic artery (SITA) grafting may not be as large as the benefit of left internal thoracic artery to left anterior descending coronary artery grafting when compared with a vein-graft-only strategy, 6 and the added benefit of incorporating additional arterial grafts depends on the importance of the bypassed non-left anterior descending coronary artery vessels.Regardless, the absence of evidence from large randomized trials, mostly because they lack long-term follow-up, does not negate the benefits associated with multiarterial grafting reported by large, well-designed observational studies and meta-analyses.1,[3][4][5]7