Left Main Coronary Artery Disease: Secular Trends in Patient Characteristics, Treatments, and Outcomes.

Left main coronary artery (LMCA) disease is the highest-risk lesion subset of ischemic heart disease, and has traditionally been an indication for coronary artery bypass grafting (CABG). Recent evidence suggests comparable clinical outcomes between percutaneous coronary intervention (PCI) and CABG for LMCA disease, with similar rates of mortality and serious composite outcomes, a higher rate of stroke with CABG, and a higher rate of repeat revascularization with PCI. These results have been translated to the current guideline recommendation that PCI is a reasonable alternative to CABG in patients with low to intermediate anatomic complexity. However, how the characteristics, treatment, and clinical outcomes of patients with unprotected LMCA disease have evolved over time has not yet been fully evaluated. We therefore described secular trends in the characteristics and long-term outcomes of unprotected LMCA disease using "real-world" clinical experience from the IRIS-MAIN (Interventional Research Incorporation Society-Left MAIN Revascularization) registry together with a broad review of this topic.