Registry Analysis Finds No Statistically Detectable Mortality Difference Between PCI and CABG for Left Main Coronary Disease

A new analysis published Tuesday in The Lancet reported no statistically detectable difference in long-term all-cause mortality between two major treatments for left main coronary artery disease: percutaneous coronary intervention, or PCI, using drug-eluting stents, and coronary artery bypass grafting, or CABG.

But the paper also stresses an important limitation. “In this non-randomised registry analysis of patients with left main coronary artery disease, there was no statistically detectable difference in all-cause mortality between PCI and CABG,” the article summary said. It added that the findings are observational and “cannot establish causal treatment effects or equivalence in survival.”

That distinction matters in a high-stakes condition. Left main coronary artery disease affects a vessel that supplies a large share of the heart muscle, making treatment choice especially consequential. The decision between a less invasive stenting procedure and open-heart bypass surgery can shape not just survival, but also recovery time, stroke risk and the likelihood of needing another procedure later. For patients who appear to be candidates for either option, the article said, “multidisciplinary Heart Team discussion might help patients and clinicians weigh potential trade-offs in the choice between PCI and CABG.”

The study, published Nov. 3 under the title “Long-term outcomes after percutaneous coronary intervention with drug-eluting stents versus coronary artery bypass grafting for left main coronary artery disease: a prospective analysis of the multicentre IRIS-MAIN registry,” draws on IRIS-MAIN, a large prospective multicenter and multinational registry of left main disease. The registry is listed on ClinicalTrials.gov as NCT01341327, with Seung-Jung Park of Asan Medical Center named as sponsor and investigator. Related IRIS-MAIN findings were also presented at TCT 2026, a major cardiology meeting in San Diego, where program listings showed Duk-Woo Park presenting long-term survival data on coronary revascularization for unprotected left main disease.

The new report lands in the middle of a debate that has lasted for years. Randomized trials comparing PCI and CABG in left main disease have produced mixed long-term signals. A 2021 Lancet individual-patient meta-analysis suggested broadly similar long-term mortality overall between the two strategies, while other studies, including NOBLE, found worse composite outcomes with PCI, driven largely by heart attacks and repeat procedures. Across the broader literature, repeat revascularization — another procedure to restore blood flow — has generally been more common after PCI.

That is also why the new registry analysis is best read as one more piece of evidence rather than a final verdict. European and U.S. guidelines already support Heart Team decision-making and allow PCI as an option in selected patients with left main disease when both PCI and CABG are feasible.

The IRIS-MAIN findings add real-world, long-term data to that discussion. But because the study was observational and non-randomized, it should be viewed as supportive context for individualized treatment decisions, not as a definitive answer to the PCI-versus-CABG question.