Abstract 21176: Can Intramural Iron Serve as a New Marker of Vulnerable Plaque?
Intraplaque hemorrhage is considered a sign and potentially a contributor of plaque instability. We hypothesize that subsequent iron deposits from plaque hemorrhage could be used, measured, and imaged as a naturally occurring marker of plaque vulnerability. We screened our unique tissue bank, which contains all 3 coronary arteries of more than 4000 deceased patients, for sudden cardiac death, myocardial infarction (MI), atherosclerosis, and normal coronary arteries. We analyzed a total of 97 arteries containing: 31 stable plaques, 24 vulnerable, and 22 normal segments. Slides were stained with HE, eVG, and specialty stains. Histological parameters included presence and amount of iron deposits [score 0–4], plaque and lumen size, percentage of stenosis, presence and size of plaque hemorrhage, size of fibrous cap and necrotic core, vasa vasorum density. Plaques were assigned to the 3 groups (normal, stable, and unstable) based on established criteria in the literature. Semi-quantitative mean iron content was significantly higher in unstable versus stable plaques and absent in normal coronary arteries (3.6 vs 2.1 vs 0; p<0.001) (Fig 1). A subgroup of plaques were scanned by micro-CT, with a Medipix, spectral scanning, x-ray imaging array, which demonstrated feasibility of using iron as an imaging marker of vulnerable/ruptured plaques (Fig 2) and excellent concordance between CT images and histology.
- © 2010 by American Heart Association, Inc.