BEST Trial Finds CABG Outperforms EES for Treating Multivessel CAD

March 16, 2015—The BEST (Bypass Surgery Versus Everolimus-Eluting Stent [EES] Implantation for Multivessel Coronary Artery Disease [CAD]) trial was presented at the 64th annual scientific session of the American College of Cardiology (ACC) in San Diego, California. The study was simultaneously published online in The New England Journal of Medicine. The BEST study’s Lead Investigator is Seung-Jung Park, MD, a cardiologist at Asan Medical Center in Seoul, South Korea.

According to the ACC, the BEST trial is one of only two randomized controlled trials to compare coronary artery bypass graft surgery (CABG) to percutaneous coronary intervention (PCI) since the introduction of EES. BEST showed that patients with multivessel CAD treated by CABG fared better than patients treated by PCI with an EES. 

The BEST findings align with those from the SYNTAX study of the Taxus drug-eluting stent (Boston Scientific Corporation) versus CABG for the treatment of narrowed arteries.

The BEST study included 880 patients treated at 27 hospitals in four countries. All patients had multivessel CAD and were determined to be equally appropriate candidates for either PCI or CABG. Patients were randomized 1:1 to receive either PCI with an EES or CABG. The average follow-up was more than 4.5 years. 

According to the ACC announcement’s summary of the study’s findings, in BEST, patients receiving PCI with EES compared to treatment by CABG had a 47% higher risk of one of the outcomes identified as a primary endpoint in the study: death, myocardial infarction (MI), and target vessel revascularization (TVR). The study reinforces current guidelines, which recommend CABG for treating patients with multivessel CAD. 

Death, MI, or TVR occurred in 15% of patients in the PCI group and 11% of patients in the CABG group. In addition, the BEST investigators found that patients who underwent PCI were twice as likely to need repeat revascularization and more than 1.8 times as likely to have a heart attack as patients who underwent CABG.

Dr. Park commented in the ACC press release, “Based on our data, CABG is still the preferred option for multivessel disease. We had thought that previous trials may have been limited by their use of first-generation drug-eluting stents, but these results show CABG still leads to better outcomes.” 

Dr. Park added, “During this relatively long-term follow-up, angioplasty was associated with a significant increase in the incidence of the death, MI, and TVR, a difference that was mainly attributed to the higher rate of TVR in the angioplasty group.” 
 
The ACC stated that the BEST study was terminated earlier than planned, limiting its statistical power to detect differences in individual outcomes instead of only composite outcomes. The early termination was caused by slow enrollment, thought to be a consequence of the rapid spread and increased appeal of fractional flow reserve (FFR) during the later part of the study enrollment period.

The ACC advised that in the BEST and SYNTAX studies, PCI was guided by angiography. By contrast, FFR allows physicians to more precisely assess the condition of the arteries based on the pressure of blood as it flows through them and has been associated with better outcomes for angioplasty. A new study is underway to compare outcomes from CABG to PCI using FFR in patients with multivessel CAD.