Abstract: | Human coronary artery wall architecture was analyzed in detail in 127 histologic sections with varying degrees of narrowing due to atherosclerotic plaque. A planimetry-microscope system was used to morphometrically determine percent luminal cross-sectional area narrowing due to atherosclerotic plaque, absolute area of the coronary artery media and total cross-sectional area of the coronary artery section. In 65 sections in which the native coronary artery lumen was narrowed less than 75%, the area of the coronary artery media corrected for total coronary cross-sectional area (Mc) was 0.244 +/- 0.055 mm2. In contrast, among 62 sections in which the coronary artery lumen was narrowed more than 75% in cross-sectional area, Mc measured 0.180 +/- 0.078 (p less than 0.001). Thus, in coronary artery segments with advanced atherosclerosis, there is substantial attenuation of the media, normally the principal component of the coronary artery wall. |