Abstract 17545: Ex vivo Evaluation of Coronary Yellow Plaque on Coronary Angioscopy: A Histopathological Validation Study
Background: Yellow color intensity of coronary plaque evaluated by coronary angioscopy (CAS) might be associated with plaque vulnerability. However, the histopathological comparison data is limited. We evaluated the histological characteristics of yellow plaques characterized by CAS in coronary autopsy specimens.
Methods: We longitudinally sectioned 65 coronary arteries from 26 autopsy hearts with noncardiovascular death. The harvested arteries were imaged with intravascular ultrasound (IVUS) >70 mm length to identify the focal plaque (plaque burden >50%). CAS examinations were performed for each focal plaque to evaluate plaque color and all focal plaques were graded either white or yellow. The border characteristic of yellow plaque was also assessed (sharp or diffuse border). A necrotic core, which is considered as a key determinant of plaque vulnerability, is defined as areas in which the extracellular matrix was lacking and replaced by dead cells and cellular debris.
Results: Of 180 plaques, 64 plaques (35%) were categorized as yellow plaques: 12 had sharp and 52 had diffuse border. And 24 of 180 plaques (13%) contained necrotic core. Most yellow plaques with sharp border contained superficial calcium without lipid deposition. Yellow plaques with diffuse boarder were highly associated with prevalence of lipid accumulation. However, only 35% of yellow plaques with diffuse boarder contained necrotic core. Other plaques included extracelluler lipid and/or foam cells that are observed in the early stages of atherosclerosis. There was a significant difference between white and yellow plaques with respect to the fibrous cap thickness (345±58 versus 100±80 µm, p=0.01).
Conclusion: Various types of atherosclerotic plaques and their components, such as superficial calcium and immature lipidic component, appear as yellow on CAS. In this specific population, CAS has a limitation in detecting vulnerable plaques corresponding histological specimen.
- © 2012 by American Heart Association, Inc.