[Morphometrical characteristic of atherosclerotic plaques in the coronary arteries of humans with ischemic heart disease according to their instability index].

Morphometrical research of the atherosclerosis plaques (AP) instability and responsible for decreasing of their stability structure has been carried out by estimation of the instability index (II). II is a ratio between sum of destabilizing (lipids and macrophages) and stabilizing (collagen fibers and smooth muscular cells) AP structures. Segments of the coronary arteries were received from 45-65 years old man after a coronary artery bypass grafting. Histologic, histochemical and computer morphometric methods were used. II for every AP was estimated according to the formula introduced by M. Shiomi [22]. 3 types of AP instability degree were distinguished: stable (II < 1 for AP and AP's cover), conditionally stable (II > 1 for AP and II < 1 for AP's cover) and unstable (II > 1 for AP and AP's cover). Unstable APs were subdivided into potentially dangerous with disruption risk and really dangerous with integrity disorders (tears, disruptions, erosion, and necrosis). The potentially and really dangerous instability AP was more than in 50% of researched AP. Instability degree of AP depended on quantity of stabilizing structures, especially collagen fibers.