OCT-Defined Plaque Morphology and Clinical Outcomes After Percutaneous Coronary Intervention: An ILUMIEN IV Substudy

Optical coherence tomography (OCT) can differentiate plaque morphology (fibrous, lipidic, and calcified) within atherosclerotic lesions. The prognostic impact of predominant OCT plaque type after percutaneous coronary intervention (PCI) is unclear.

The aim of this study was to investigate clinical outcomes after PCI based on the preprocedural predominant plaque morphology from the OCT cohort of the ILUMIEN IV trial.

Subjects assigned to OCT guidance (n = 1,233) underwent core laboratory analysis to determine predominant lesion plaque morphology: lipidic (maximum arc ≥180° or thin-cap fibroatheroma), calcific (maximum arc ≥180°), or fibrotic. The primary endpoint was target-vessel failure (TVF), a composite of cardiac death, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization (ID-TVR).

PCI of a single de novo lesion was performed in 926 patients. By OCT, the plaque was predominantly lipidic, calcific, and fibrotic in 309 (33%), 252 (27%), and 365 (39%) cases, respectively. After multivariable adjustment, patients undergoing PCI of a predominantly calcific lesion had increased rates of TVF (10.7% vs 4.0%; adjusted HR: 2.20 [95% CI: 1.12-4.33]; P = 0.02) driven by greater ID-TVR (8.2% vs 3.1%; adjusted HR: 2.31 [95% CI: 1.08-4.96]; P = 0.03) compared with PCI of a fibrotic lesion. Event rates in patients undergoing PCI of a predominantly lipidic lesion were intermediate (TVF 5.6% and ID-TVR 4.0%).

Based on preprocedural OCT, PCI of calcific and fibrotic plaques was associated with the highest and lowest 2-year rates of TVF and ID-TVR, respectively, with lipidic plaques being of intermediate risk. This is the first report from a large-scale clinical trial that demonstrates the prognostic utility of baseline OCT plaque morphology on post-PCI outcomes. (ILUMIEN IV: OPTIMAL Percutaneous Coronary Intervention [PCI]; NCT03507777).