NEW ORLEANS, LA—Percutaneous coronary intervention (PCI) with sirolimus-eluting stents was found noninferior to coronary artery bypass graft (CABG) surgery for the primary endpoint of major cardiac or cerebrovascular events (MACCE) in patients with unprotected left main coronary artery stenosis, according to findings presented during a late-breaking clinical trials session April 4, 2011, at the annual American College of Cardiology Scientific Session/i2 Summit.

Presenting the results of the PRECOMBAT (Premier of Randomized Comparison of Bypass Surgery versus Angioplasty Using Sirolimus-Eluting Stent in Patients with Left Main Coronary Artery Disease) trial, Seung-Jung Park, MD, PhD, of the Asan Medical Center (Seoul, South Korea), explained that while the trial “suggests” that PCI using Cypher (Cordis, Miami Lakes, FL) stents appears to be a reasonable alternative to CABG, the noninferiority margins were too wide for the findings to be considered definitive.

The results were simultaneously published online ahead of print in the New England Journal of Medicine.

PRECOMBAT

To better define the role of PCI with sirolimus-eluting stents in the treatment of unprotected left main disease, Dr. Park and colleagues enrolled 600 patients with a de novo left main stenosis greater than 50% by visual estimate. Participants were randomly assigned to CABG (n = 300) or PCI with sirolimus-eluting stent implantation (n = 300).

Based on historical outcomes data, the investigators estimated that the incidence of the primary composite endpoint of death from any cause, MI, stroke, or ischemia-driven TVR 1 year after CABG would be 13%. A “wide” noninferiority margin of 7 percentage points was chosen to compare the 2 treatment strategies for the absolute difference in risk at 1 year.

The 1-year rates of the primary endpoint for PCI compared to CABG were 8.7% vs. 6.7%, respectively (P = 0.39; P = 0.001 for noninferiority).

However, because the event rate at 1 year did not reach the anticipated level of 13%, Dr. Park and colleagues conducted post hoc survival analyses that compared events in the 2 groups at 2 years. They found that MACCE rates still did not differ between groups, nor did the rates of any of the MACCE components except for ischemia-driven TVR, which was higher in the PCI arm (table 1).

Table 1. Primary Outcome Results at 2 Years

Abbreviation: MI, myocardial infarction; TVR, target-vessel revascularization.
^aComposite of death, MI, stroke, ischemia-driven TVR.

Similarly, no difference was noted in the composite rate of death, MI, or stroke at 2 years (4.4% with PCI vs. 4.7% with CABG; P = 0.83). Symptomatic graft occlusion and stent thrombosis was seen in 0.3% of PCI patients and in 1.4% of CABG patients at 2 years (P = 0.18).

The results were consistent across multiple subgroups, including older and younger patients, men and women, patients with bifurcation involvement, right coronary artery involvement, ACS and diabetes. Interestingly, MACCE rates also indicated equivalence for PCI and CABG in patients with lower and higher Syntax scores. Only in patients with left main plus triple vessel disease was CABG associated with a statistically significant reduction in MACCE (16.8% with PCI vs. 5.8% with CABG; P = 0.01).

Directive in Less Complex Patients

“It’s clear that unprotected left main coronary artery disease can be treated interventionally,” said James B. McClurken of Temple University School of Medicine (Philadelphia, PA). “What is clear is that the less complex lesions seem to have equal outcomes with surgery and intervention at least out to 2 years in this trial and 3 years in the SYNTAX trial.” He also noted the “wonderful outcomes” seen with PCI in the more complex lesions, including bifurcation lesions. 

Panel member Bernard Gersh, MB, ChB, of the Mayo Clinic (Rochester, MN), said that he would probably recommend PCI for patients with less non-left main disease and lower Syntax scores and reserve CABG for individuals with diffuse multivessel disease, diabetes, and higher Syntax scores. For those in the middle, he would “individualize” treatment.

“We are clearly at the point where we can discuss PCI with a patient with unprotected left main disease,” Dr. Gersh said. “What would sway me [between PCI and CABG] would be the extent of the non-left main disease.”

All the panelists stressed the need for more data. Session co-moderator Gregg W. Stone, MD, of Columbia University Medical Center (New York, NY), noted that the EXCEL trial, which is still in the planning stages, will enroll 3,100 patients with unprotected left main disease and randomize them to either CABG or PCI with the everolimus-eluting Xience stent.

Sources:

Park S-J, Kim Y-H, Park D-W, et al. Randomized trial of stents vs. bypass surgery for left main coronary artery disease. N Engl J Med. 2011;Epub ahead of print.

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