IVUS-Guided Versus Angiography-Guided Left Main Coronary Artery Stenting

This observational cohort study compared outcomes in 975 patients undergoing PCI for unprotected left main coronary artery stenosis, stratified by whether the procedure was performed with IVUS guidance or angiographic guidance alone.

IVUS-guided left main PCI was associated with significantly lower 3-year mortality than angiography-guided PCI (4.7% vs. 16%, adjusted HR 0.54). The IVUS group also had lower rates of MACE at follow-up. In the IVUS group, operators were more likely to use larger stent diameters and higher deployment pressures — consistent with the hypothesis that IVUS reveals the true vessel dimensions and enables optimal stent sizing that angiography cannot provide.

Left main PCI is among the highest-stakes interventional procedures: the left main coronary artery supplies the majority of the left ventricular myocardium, and stent failure carries catastrophic consequences. In this context, the magnitude of the mortality difference is striking and clinically meaningful, even accounting for the observational design and potential for selection bias (IVUS may have been preferentially used in more experienced centers).

These findings have contributed to the strong guideline recommendations for IVUS guidance in left main PCI, now reflected in ESC and ACC/AHA interventional cardiology guidelines.

We rate the evidence moderate. A large observational study showing a strong association between IVUS guidance and survival in left main PCI — important for establishing the practice standard, though subject to confounding inherent in non-randomized comparisons.