NEW ORLEANS – Select patients with unprotected left main coronary artery stenosis can be effectively treated with percutaneous coronary intervention with sirolimus-eluting stents rather than coronary artery bypass grafting, South Korean investigators reported at a the April 4 late-breaking clinical trials session of the annual meeting of the American College of Cardiology.
"PCI with sirolimus-eluting stents appears to be an alternative to coronary artery bypass grafting based on a noninferior incidence of major cardiac and cerebrovascular events" in a median 2-year follow-up of 600 patients with unprotected left main coronary artery stenosis randomized to undergo either CABG or PCI with a sirolimus-eluting stent [Cordis, Johnson & Johnson], said Dr. Seung-Jung Park, the principal investigator of PRECOMBAT (Premier of Randomized Comparison of Bypass Surgery Versus Angioplasty Using Sirolimus-Eluting Stent in Patients With Left Main Coronary Artery Disease).
Major adverse cardiac or cerebrovascular events (MACCE) included all-cause death, myocardial infarction, stroke, ischemia-driven target-vessel revascularization, and cerebrovascular events, said Dr.Park of Asan Medical Center, Seoul, South Korea.
The rate of MACCE at 2 years was comparable at 12.2% for PCI-treated patients and 8.1% for CABG-treated patients. The composite of death, myocardial infarction and stroke – which the investigators considered a marker of safety – was 4.4% in the PCI group and 4.7% in the CABG group. The major difference was the rate of ischemia-driven target-vessel revascularization – 9% with PCI and 4.2% with CABG.
Further, in subgroup analyses, PCI was associated with a higher risk of MACCE in patients with unprotected left main coronary artery stenosis plus three-vessel disease.
Concomitant with the presentation, the results were published online in the New England Journal of Medicine (N. Engl. J. Med. 2011, April 4 [doi: 10.1056/NEJMoa1100452]).
PRECOMBAT baseline patient characteristics were similar. Mean age was 62 years, 76.5% were men, mean ejection fraction was 60% and high operative risk was noted for 6% of the PCI group and 8% of the CABG group. Median follow-up was 24 months.
The primary end point was a composite comparison of MACCE at 1 year and 2 years. The primary analysis was a noninferiority comparison.
MACCE occurred in 26 patients assigned to PCI and in 20 patients assigned to CABG, for cumulative event rates of 8.7% and 6.7%, respectively. The 2.0% absolute risk difference supported noninferiority of PCI to CABG (P = .01). When patient analysis was based on the actual treatment received, however, the 1-year cumulative MACCE rates were 9.2% for PCI and 5.9%, for CABG (P = .04 for noninferiority).
The all-cause death rate in year 1 was 2% for PCI and 2.7% for CABG and in year 2 was 2.4% and 3.4%, respectively (P = .45). Cardiac deaths occurred in 1.0% and 2.7%, respectively, at 2 years.
Strokes and myocardial infarction were also infrequent and the rate of these events did not differ between the treatment arms. Symptomatic graft occlusion and stent thrombosis were observed in 0.3% of the PCI group and in 1.4% of the CABG group. There were no differences by subgroup.
Describing the procedural characteristics, Dr. Park noted that in the PCI group the mean number of stents per patient was 2.7 and in the CABG group the mean number of grafts was 2.7. The procedures were completed in 205 PCI patients and in 211 CABG patients, for comparable revascularization rates of 68% and 70%, respectively.
"Our major finding, that event rates after PCI and CABG did not differ significantly in this clinical setting, are in agreement with the results of the SYNTAX substudy involving patients with left main coronary artery stenosis," Dr. Park said.
In SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery), CABG showed more benefit than did PCI for the overall study population (N. Engl. J. Med. 2009;360:961-72).
Among patients with left main coronary artery disease in SYNTAX, however, the 12-month rate of MACCE was similar at 13.7% in the CABG group and 15.8% in the PCI group (P = .44). The rate of repeat revascularization among patients with left main coronary artery disease was 11.8% in the PCI group and 6.5% in the CABG group (P = .02), but the CABG group had a 2.7% rate of stroke as compared to a 0.3% rate in the PCI subgroup; (P = .01). In SYNTAX, nearly 37% of patients with left main coronary artery disease also had three-vessel disease. The subgroup with concomitant two- or three-vessel disease had higher MACCE rates than did the subgroups of patients with left main coronary artery disease alone or in combination with one-vessel disease.