Bypass surgery superior to stents for complex coronary disease [BEST trial]

1. In patients with multi-vessel coronary artery disease, bypass surgery was associated with fewer adverse events than stenting with modern drug-eluting stents.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Previous trials comparing coronary artery bypass grafting (CABG) to percutaneous coronary intervention (PCI) with stents have shown that CABG has better clinical outcomes in patients with multi-vessel coronary artery disease. However, second-generation drug-eluting stents are safer and more effective than the first-generation stents used in prior trials. The BEST trial addresses the question: are second-generation drug eluting stents non-inferior to CABG in patients with multivessel coronary artery disease?

The study was terminated early due to slow enrollment. At the pre-specified 2-year endpoint, the trial did not demonstrate non-inferiority of PCI to CABG. Over long-term follow-up, the PCI group had more spontaneous myocardial infarctions (MI) and more repeat revascularizations than the CABG group. Previous trials have found that a higher rate of stroke with CABG compared to PCI, but there was no difference in this trial.

Although PCI was not non-inferior in a general population of patients with multi-vessel coronary artery disease, there may be sub-populations in which PCI could be appropriate. For example, the authors found no significant difference in outcomes between PCI and CABG among non-diabetics, while there was a significant increase in adverse events among diabetics who got PCI rather than CABG. Another example may be patients in which complete revascularization via PCI is possible. Complete revascularization was only achieved in 50% of patients in the PCI group compared to 71.5% in the CABG group. This difference could have been a driver of the increased need for repeat revascularization in the PCI group compared to the CABG group. Thus, the issue of PCI vs. CABG may be also be a question of patient selection.

Click to read the study, published today in NEJM

Click to read an accompanying editorial in NEJM

Relevant Reading: Everolimus-Eluting Stents or Bypass Surgery for Multivessel Coronary Disease

In-Depth [randomized controlled trial]: This trial enrolled 880 East Asian patients from sites in South Korea, China, Malaysia and Thailand. The study’s target enrollment was 1776 based on a 12% incidence of the primary endpoint at 2 years in the CABG group, a non-inferiority margin of 4% and a power of 80%.

At 2 years, the primary end point had occurred in 11% of patients in the PCI group and 7.9% of patients in the CABG group. The absolute risk difference was 3.1% with a 95% confidence interval of -0.8 to 6.9. Non-inferiority of PCI could not be established since the 95% CI included the pre-specified non-inferiority margin of 4%.

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