Optical Coherence Tomography — Light and Truth

This NEJM editorial interprets the ILUMIEN IV and OCTOBER trials, which evaluated whether optical coherence tomography (OCT) guidance improves outcomes in complex percutaneous coronary intervention (PCI). OCT provides near-infrared microstructural imaging of coronary arteries with 10–15 μm resolution far exceeding intravascular ultrasound. Findings from OCT imaging have reshaped understanding of coronary disease pathophysiology, revealing plaque erosion, thin-cap fibroatheromas, and calcified nodules. The editorial notes both trials used sophisticated algorithms targeting maximal lumen diameter and complete stent expansion, but diverged in outcomes: OCTOBER showed reduced major adverse cardiac events with OCT guidance (10.1% vs. 14.1%; HR 0.70), while ILUMIEN IV, despite larger stent areas showed no significant difference in target-vessel failure. RENOVATE-COMPLEX-PCI further validated imaging guidance with superiority over angiography. While heterogeneity remains, the editorial suggests these trials collectively support intracoronary imaging as a class-effect tool for PCI optimization particularly in complex lesions. Caution is urged in oversimplifying the findings, noting nuanced trial designs and lesion selection.

This NEJM editorial interprets the ILUMIEN IV and OCTOBER trials, which evaluated whether optical coherence tomography (OCT) guidance improves outcomes in complex percutaneous coronary intervention (PCI). OCT provides near-infrared microstructural imaging of coronary arteries with 10–15 μm resolution far exceeding intravascular ultrasound. Findings from OCT imaging have reshaped understanding of coronary disease pathophysiology, revealing plaque erosion, thin-cap fibroatheromas, and calcified nodules. The editorial notes both trials used sophisticated algorithms targeting maximal lumen diameter and complete stent expansion, but diverged in outcomes: OCTOBER showed reduced major adverse cardiac events with OCT guidance (10.1% vs. 14.1%; HR 0.70), while ILUMIEN IV, despite larger stent areas showed no significant difference in target-vessel failure. RENOVATE-COMPLEX-PCI further validated imaging guidance with superiority over angiography. While heterogeneity remains, the editorial suggests these trials collectively support intracoronary imaging as a class-effect tool for PCI optimization particularly in complex lesions. Caution is urged in oversimplifying the findings, noting nuanced trial designs and lesion selection.