Percutaneous coronary intervention (PCI) using everolimus-eluting stents was found noninferior to coronary artery bypass grafting (CABG) with respect to the composite end point of death, stroke, or myocardial infarction at 3 years among patients with left main coronary artery disease and low or intermediate anatomical complexity, according to a report presented at the Transcatheter Cardiovascular Therapeutics annual meeting and published simultaneously in the New England Journal of Medicine.
The rate of this composite outcome was lower with PCI than with CABG during the first 30 days following the procedure, but higher between day 30 and year 3. In addition, the 3-year rate of revascularization was slightly higher with PCI (23.1% vs 19.1%), but the rate of periprocedural MI and major adverse events was lower (8.1% vs 23.0%).
Taken together, these results “suggest that PCI with everolimus-eluting stents is an acceptable or perhaps preferred alternative to CABG in selected patients with left main CAD who are candidates for either procedure,” said Gregg W. Stone, MD, of Columbia University Medical Center, New York, and his associates in the EXCEL (Evaluation of XIENCE versus CABG for Effectiveness of Left Main Revascularization) trial.
This study was funded by Abbott Vascular, maker of the everolimus-eluting stent (the XIENCE). The company also participated in the design of the trial and in the selection and management of the treatment sites.
Until now, it was generally agreed that most patients with left main CAD would have better outcomes with CABG than with PCI, based on the results of earlier trials comparing the two approaches. But contemporary drug-eluting stents have better safety and efficacy profiles than first-generation stents, and surgical techniques have also improved over time, so a study comparing the current standards of care was warranted, Dr. Stone and his associates said (New Engl J Med. 2016 Oct 31. doi:10.1056/NEJMoa1610227).
They assessed 1,905 patients at 126 medical centers in 17 countries in the open-label noninferiority trial. Participants had left main coronary artery stenosis of 70% or more (estimated visually) or of 50%-70% (estimated by invasive or noninvasive testing) if the stenosis was judged to be hemodynamically significant. The study participants also were required to have low or intermediate anatomical complexity of the involved portion of the coronary artery, as defined by a SYNTAX score of 32 or lower. A total of 948 patients were randomly assigned to PCI and 957 to CABG.
The primary composite end point – the rate of death, stroke, or MI assessed at a median of 3 years of follow-up – was 15.4% with PCI and 14.7% with CABG, a nonsignificant difference (Hazard Ratio, 1.00) that demonstrates the noninferiority of PCI. This rate was consistently noninferior across all subgroups of patients, regardless of age, sex, and the presence or absence of diabetes or chronic kidney disease.
At 30 days, the rate of the composite end point was 4.9% with PCI and 7.9% with CABG, which also demonstrates the noninferiority of PCI. At 3 years, secondary end points including the rate of ischemia-driven revascularization also showed the noninferiority of PCI, as did each of the individual components of the primary composite end point.
The rate of death, stroke, or MI was lower at 30 days with PCI than with CABG, mainly because there were fewer MIs with PCI. But a post-hoc analysis showed that this rate was higher with PCI than with CABG after 30 days.
During follow-up, ischemia-driven revascularization was more common after PCI (12.6%) than after CABG (7.5%). However, symptomatic graft occlusion after CABG (5.4%) was more frequent than definite stent thrombosis after PCI (0.7%).
Periprocedural major adverse events developed in 8.1% of the PCI group and 23.0% of the CABG group, and the difference was attributed mainly to fewer arrhythmias, infections, and blood transfusions in the PCI group. Cardiovascular mortality was similar between the two study groups, though all-cause mortality was higher with PCI due to an excess of fatal infections and malignancies in that group.
The investigators noted several limitations with the EXCEL trial. First, treatment blinding wasn’t possible, so some degree of bias may have resulted.
Second, prerandomization SYNTAX scores estimating the anatomical complexity of the affected vessels weren’t always accurate, and 24% of the patients in this study proved to have complex lesions when their procedures were undertaken. However, the rate of the primary composite end point was the same in this subgroup of patients as in the overall patient population.
Third, long-term medications after PCI differ from those after CABG, and the investigators said further study is needed to determine how these differences may have contributed to patient outcomes. And finally, longer follow-up is needed to assess whether more differences between the two study groups emerge over time. Five-year follow-up of this study population is now under way.
Dr. Stone and his associates reported ties to numerous industry sources.