Debate: PCI vs. CABG for Left Main Disease

SAN FRANCISCO, CALIF.—In a contribution to the ongoing debate over which patients with unprotected left main disease should be treated with PCI vs. CABG, an interventionalist concluded that based on SYNTAX results, PCI is a viable alternative for more than half of left main patients, and the percentage may increase with new-generation DES. In the same session, a surgeon maintained his stance in favor of CABG.

Interventionalist Thierry Lefevre, MD, of the Institut Hospitalier Jacques Cartier in Massy, France, recalled the SYNTAX trial was an attempt, in the wake of technological advances and changing practice, to help determine the appropriate roles for PCI vs. CABG in the treatment of patients with complex anatomy in a “real world” setting.

In the left main subset, at 1 year, rates of the primary endpoint of MACCE (death, MI, stroke, and repeat revascularization) were similar between PCI and CABG (15.8% and 13.6%, respectively; P=.44), while stroke was increased with CABG (2.7% vs. 0.3%; P=.009) and repeat revascularization was higher with PCI (12% vs. 6.7%; P=.02). The same pattern was observed at 4 years. In addition, no differences were seen across left main subsets, from isolated through 3-vessel disease.

Outcomes diverged, however, when patients were stratified by SYNTAX risk score, opening a niche for PCI. In the low and intermediate risk categories (0-32), MACCE rates were similar (29% for CABG and 27.6% for PCI; P=.65), while among those with high scores (≥33), CABG retained an advantage (26.3% vs. 42.6%; P<.003).

In 2009, the ACC/AHA guidelines were updated, raising left main stenting from a Class III to a Class IIb recommendation, with evidence level B. The following year, the ESC/EACTS guidelines upgraded left main (isolated or in conjunction with single-vessel disease) stenting from Class IIb C to IIa B.

Lefevre noted that changes in interventional practice can influence outcomes. Comparison of data from the French TAXUS and LEMAX registries showed that the 1-year MACCE rate for paclitaxel-eluting stent-treated patients with the lowest Syntax scores were similar to the rate for everolimus-eluting stent-treated patients with the highest Syntax scores.

Surgery as mainstay

Surgeon David P. Taggart, MD, of the University of Oxford in the United Kingdom, held the ground for surgery, citing his 2008 state-of-the-art paper which concluded that surgical revascularization should remain the preferred revascularization strategy in left main disease, especially in light of the fact that up to 90% of left main stenoses involve distal or bifurcation disease, which has a very high risk of restenosis. In addition, up to 90% of left main patients have multivessel CAD, for which CABG has been shown to convey a survival benefit independent of left main stenosis.

Taggart argued against giving undue weight to the randomized trials comparing PCI and CABG. Although they are the gold standard for research, they typically include small numbers of patients who are often atypical and have short follow-up. On the other hand, 8 registries involving tens of thousands of more representative patients have consistently shown a survival advantage for CABG of about 5% at 3 years. And the only randomized trial of the same kinds of patients, the aforementioned SYNTAX, yielded the same finding at 4 years. 

Meanwhile, in a multicenter registry in which most patients had ostial or mid shaft lesions, PCI showed good results, with 3.4% mortality and 5% revascularization at 2.5 years.  And a recent meta-analysis of four randomized trials by Capodanno and colleagues showed no difference between PCI and CABG at 1 year for MACCE (14.5% vs. 11.8%; P=.11), but a higher rate of stroke (1.7% vs. 0.1%; P=.013) and a lower rate of repeat revascularization (5.4% vs. 11.4%; P<.001) with CABG.

In the randomized PRECOMBAT trial involving mainly patients at low and intermediate risk, rates for the composite endpoint of death, stroke, MI, and revascularization were similar for the two strategies. But, importantly, said Taggart, unlike in SYNTAX, there was no increase in stroke or mortality in this lower-risk population. 

In summary, Taggart observed that 65% of all patients with left main disease have SYNTAX scores >32 and will have a strong survival advantage with CABG even by 3 years. On the other hand, PCI appears to be a good option for ostial and mid-shaft lesions with or without single vessel CAD.