Abstract 14028: Diagnostic Accuracy of Optical Frequency Domain Imaging for Identifying Necrotic Core With Intraplaque Hemorrhage in Advanced Human Carotid Plaques: A Histopathological Validation Study
Introduction: Optical frequency domain imaging (OFDI), a light-based high-resolution imaging, has been shown to be capable of identifying vulnerable plaque constituents, such as necrotic core.
Hypothesis: OFDI is capable of imaging plaque morphologies for advanced atherosclerotic carotid artery plaques, focusing on size of necrotic core and intraplaque hemorrhage (IPH).
Methods: Eleven symptomatic patients scheduled for carotid endarterectomy underwent OFDI at the preoperative angiography. Specimens were excised intact without disruption of the luminal surface within 72 hours after OFDI. Sections were taken every 3 mm and stained for histological evaluation (65 sections). The histological diagnoses were classified into either fibrous tissue, superficial foam cells, necrotic core, calcification, and organized thrombus. The ratio of IPH/plaque area was graded into 3 scales: 3, ≥40%; 2, ≥20%; 1, <20%. OFDI signals from tissues were quantitatively analyzed by measuring the OFDI signal intensity, and an attenuation rate was calculated from an exponential formula.
Results: There was a good correlation of the fibrous cap thickness between OFDI and histology (y = 0.86x + 4.8; r = 0.92; p <0.001). Necrotic core appeared as dark areas with diffuse borders, whereas fibrous tissue as bright areas as previously reported in native coronary arteries. When tissue types were ranked according to their attenuation rates, necrotic core was highest, then foam cells accumulation, organized thrombus, calcification, and fibrous tissue (p<0.001). Moreover, higher IPH score was significantly associated with higher attenuation rate on OFDI (p <0.001, Figure).
Conclusions: The OFDI provides high diagnostic accuracy for the analysis of the tissue characteristics, including large necrotic core with high-grade IPH, of carotid artery plaques. This high-resolution imaging technique has the potential to alter the understanding and treatment of carotid artery disease.
Author Disclosures: K. Fujii: None. H. Hao: None. S. Shindo: None. M. Shirakawa: None. K. Uchida: None. R. Kawakami: None. K. Kawai: None. S. Hirota: None. S. Yoshimura: None.
- © 2016 by American Heart Association, Inc.