Abstract 1914: Vulnerable Plaque Pathology for Imagers
Background: Knowledge of precise characteristics of vulnerable plaques (VP) is needed to develop noninvasive imaging technology for their detection. Ruptured atherosclerotic plaques associated with acute coronary events are pathologically described as positively remodeled vessels containing atheromatous cores, with thin and inflamed disrupted caps. It is expected that the VP demonstrate similar pathologic features.
Methods: 375 atherosclerotic plaques were histopathologically analyzed from the victims of sudden coronary death and classified as early or late core fibroatheromas (FA; n = 254), thin-cap fibroatheroma (or VP; n = 52) and ruptured plaques (RP; n = 69). Descriptive analyses of various plaque characterisitics were performed with ANOVA and chi square tests. A multivariate logistic regression adjusting for age, gender, race, and plaque characteristics predicted unstable (VP + RP) versus stable (FA) plaques.
Results: Independent predictors of the likelihood of unstable plaque were
necrotic core area: odds ratio [OR] and 95% confidence intervals of 2.8 (1.3– 6.2) for 2nd and 6.0 (2.5–14) for 3rd, vs. 1st tertile,
plaque area: 4.9 (2.1–11.3) for 3rd vs. 1st tertile, and
macrophage area: 4.0 (2.0 – 8.1) for 3rd vs. 1st tertile (all p < 0.05 to p < 0.001).
Bivariate relationship was significant only for plaque area and necrotic core area relationship, relationship was not affected by macrophage area.
Conclusions: Larger extent of the plaque area and the largest magnitude of necrotic core determine the likelihood of plaque rupture. Any noninvasive diagnostic strategy will need to target these two morphological features for the detection of unstable lesions.