Long-term outcomes after left main percutaneous coronary intervention (PCI) may depend on procedural optimization, although the prognostic role of post-procedural intravascular ultrasound (IVUS) remains uncertain. A post hoc analysis of the NOBLE Trial presented at EuroPCR 2026 evaluated long-term outcomes according to IVUS use after PCI for unprotected left main coronary artery (LMCA) disease.

The NOBLE trial randomized 1,201 patients with unprotected LMCA disease to PCI or coronary artery bypass grafting (CABG) between 2008 and 2015 across 36 centers in Northern Europe. Patients were followed for major adverse cardiac and cerebrovascular events (MACCE) through 5 years and all-cause mortality through 10 years.

In this analysis, PCI-treated patients were stratified according to post-procedural IVUS use and compared with as-treated CABG patients. Propensity-adjusted Cox regression analyses were used to account for baseline differences.

Findings

• In the as-treated cohort, 574 patients underwent CABG, 443 underwent PCI with post-procedural IVUS, and 160 underwent PCI without IVUS guidance.
• Crude all-cause mortality at 10 years was higher among patients undergoing PCI without IVUS compared with CABG or PCI with IVUS guidance (33.9% vs 23.3% vs 20.6%; p = 0.0047).
• After adjustment, PCI with IVUS showed similar long-term mortality risk to CABG (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.68-1.15).
• PCI performed without IVUS showed higher mortality risk compared with CABG (HR, 1.33; 95% CI, 0.98-1.81; p for treatment = 0.031).
• CABG remained associated with lower MACCE risk compared with PCI performed with IVUS (HR, 1.52; 95% CI, 1.17-1.98) and PCI without IVUS (HR, 1.59; 95% CI, 1.12-2.26; p for treatment = 0.0025).
• Minimum stent area tertiles after PCI were not significantly associated with long-term mortality outcomes.

Among patients with unprotected LMCA disease, PCI performed with post-procedural IVUS showed similar 10-year mortality to CABG. In contrast, PCI performed without IVUS was associated with worse long-term survival, although CABG remained associated with lower overall MACCE rates.