Evaluation of plaque composition using iMap-intravascular ultrasound predicts thin-cap fibroatheroma determined by optical coherence tomography

Purpose: The iMap-intravascular ultrasound (iMap-IVUS), a novel radiofrequency intracoronary imaging system, can generate objective and quantitative information about coronary plaque compositions. The aim of this study was to determine whether iMap-IVUS can detect Thin-Cap Fibroatheroma (TCFA), which is a primary type of vulnerable plaque, as determined by Optical Coherence Tomography (OCT). Methods: Seventy nine culprit plaques in 70 patients with stable and 9 with unstable angina pectoris were analyzed using iMap-IVUS and OCT. Quantitative volumetric grayscale and iMap-IVUS analysis was performed across the entire lesion segment, and cross-sectional area analysis was performed to evaluate vessel remodeling. Plaque compositions were classified using iMap-IVUS as fibrotic, lipidic, necrotic and calcified, which are expressed as absolute amounts and as a percentage of plaque volume. We defined OCT-derived TCFA as lipid-rich plaque with a