Discrepancies between data on atherosclerotic involvement of human coronary arteries furnished by gross inspection and by light microscopy

Abstract

Intimal areas located at centimetre intervals from the points of origin of the anterior descending, circumflex and right coronary arteries, as well as intimal areas located at the main branching points of the coronary tree, were compared on macro- and microscopic levels, irrespective of the presence or absence of atherosclerotic lesions in the regions selected. The study, carried out on 606 subjects aged 1-70 years, revealed important discrepancies between data furnished by gross inspection and by light microscopy. These discrepancies occurred in the recorded character of atherosclerotic lesions; the meaning of the terms 'fibrous plaque', 'fatty streak' and 'normal intima'; the age period in which the first atherosclerotic lesions were detected; the features of these early lesions and their sequence of development; and the presence of atherosclerotic plaques in the main branch vessels. The fibromuscular and mucoid plaques, intimal necrotic areas and incorporated microthrombi, occurring as early stages of atherosclerotic involvement, were visualized only by light microscopy. In mature adults and elderly people the intimal surface of many coronary artery samples had a different appearance from the basal intimal regions.