Aims Adverse plaque characteristics (APCs) by coronary computed tomography (CT) angiography (CTA) are associated with myocardial ischaemia and future acute coronary syndromes. The overall objective was to determine whether APCs on non-invasive CTA are associated with vulnerable plaque features by invasive optical coherence tomography (OCT).
Methods and results Sixty-eight coronary plaques in 45 patients were evaluated by CTA and OCT. APCs by CTA were: positive remodelling (PR), remodelling index >= 1.10; low attenuation plaque (LAP), any intraplaque voxel <30 Hounsfield units; spotty calcification (SC), intraplaque calcification <= 3 mm; and 'napkin-ring' sign, low intraplaque attenuation surrounded by a higher attenuation rim. OCT evaluated plaques for thin-cap fibroatheroma (TCFA, <= 65 mu m, lipid arch >90 degrees) and macrophage infiltration. Increasing plaque vulnerability was graded by OCT as having no TCFA, TCFA without macrophage infiltration, and TCFA with macrophage infiltration. OCT lesions included those with no TCFA (n = 44), TCFA without macrophage infiltration (n = 7), and TCFA with macrophage infiltration (n = 17). Increasing plaque vulnerability grade by OCT was associated with higher diameter stenosis (43.6 vs. 40.7 vs. 57.3%, P = 0.01), and greater prevalence of PR (11 vs. 43 vs. 71%, P < 0.001), LAP (11 vs. 29 vs. 59%, P = 0.001), and SC (2 vs. 29 vs. 18%, P = 0.02), but not for napkin-ring sign (P = 0.18). In multivariable analysis, PR [odds ratio (OR) 16.9, 95% confidence interval (CI) 3.9-73.3, P < 0.001] and LAP (OR 11.2, 95% CI 2.8-44.3, P = 0.001) predicted TCFA with macrophage infiltration, whereas SC and napkinring sign did not.
Conclusion Plaques demonstrating PR and LAP by CTA are associated with TCFA with macrophage infiltration by OCT.