Abstract
The histological findings in the subendothelial lesions of coronary arteries were observed in 14 autopsy cases who had a clinical history and ECG changes of unstable angina at rest within a month of death. 308 cross-sections (2 from each 11 segments from each heart) obtained from the cases were examined and compared with 616 sections from 28 controls who had no anginal history and ECG changes within a month of death.
Of the 308 sections from the anginal group, 76 (24.7%) were narrowed 76% to 100% by atherosclerotic plaque (control; 4.5%) and 32 (10.8%) had occulusive thrombi (control; 0%). In the subendothelial space of thickened coronary intima, the infiltration of mononuclear cells (i. e. monocytes, macrophages and foam cells) with edematous changes was present, and more frequent in the anginal group (30.4%) than the control (8.1%, p<0.01). These findings in the coronary subendothelial space may be a feature of increased endothelial permeability due to coronary vasospasm, and the repeated spasms may result in progression of coronary atherosclerosis.
