Lipid derivatives of arachidonic acid used as markers of atherosclerotic plaque instability: a pilot study.

BACKGROUND:To compare the results of computer estimation of atherosclerotic plaque with biochemical data and ascertain any relationship with the occurrence of stroke. METHODS:The study involved 20 atherosclerotic plaques causing 70-99% stenosis of internal carotid arteries (ICA). Ultrasonographic examination (USG) images of plaques were analyzed using a computer program. A histogram was obtained for each plaque and a gray scale median (GSM) was determined for each histogram in order to measure the echogenicity of an examined plaque. Then the plaques, collected during endarterectomy, were examined with regard to the concentration of prostaglandins E2 (PGE2), thromboxane A2 (TXA2), and 8 - epi-prostaglandin F2α. This data was compared with GSM and the occurrence of stroke. RESULTS:The statistical analysis showed significant correlations between low GSM and the occurrence of strokes. Out of 10 plaques with GSM 35, only 1 (10.0%) had a stroke. In addition, there were significant differences in the plaque content of PGE 2, (P<0.05) and (TXA2, P<0.011) between groups. CONCLUSIONS:High levels of PGE2 and TXA2, correlated with the low GSM values, may be the features of unstable plaques and that may be associated with a risk for stroke.