Why is this study important?   

The BEST extended follow-up study revealed that the long-term observations from the Trial of Everolimus-Eluting Stents or Bypass Surgery for Coronary Disease (up to 14 years post-randomization) are similar to the previously published short-term observations from the trial with no significant difference in MACE between PCI and CABG in patients with multi-vessel CAD without significant left main disease.  

What question was this study supposed to answer?  

The BEST trial, originally published in 2015, was designed to test non-inferiority of PCI using second generation drug-eluting stents compared to CABG in patients with multi-vessel CAD but was not powered to do so as a result of premature discontinuation of the trial resulting from slow enrollment. As the study was not powered for the primary endpoint, the authors’ conclusions provide a description of endpoint events that occurred during a median of 11.8 years of follow-up.  

What did the study show?  

The BEST trial was a prospective, multi-center, randomized trial which enrolled patients in South Korea, Thailand, China and Malaysia with multi-vessel (non-left main) disease in whom the heart team felt there was equipoise between PCI and CABG revascularization approaches. Between July 2008 and September 2013, only 880 of the planned 1,776 patients had been enrolled and the trial was prematurely terminated due to slow enrollment. As a result, the statistical power for clinical endpoints was not reached. Numerically, there was no observed difference in major adverse cardiac events (all-cause death, MI or target-vessel revascularization) between the PCI and CABG arm in long-term follow-up, similar to the short-term observations published in the original trial. Although the authors also report on secondary endpoint data indicating numerically higher rates of spontaneous MI and repeat revascularization, the interpretation of these data in the absence of statistical power for the primary endpoint should only be considered hypothesis-generating.  

All editors: Allison G. Dupont, MD, FSCAI