Atherosclerotic change of coronary artery was examined with reference to advancing age in autopsied materials obtained at Tokyo Medical Examiner's Office (a forensic institute) and Harunaso Hospital (a geriatric hospital). Severity of atherosclerosis was evaluated by two methods. One is measurement of the surface involvement stained by Sudan 4 and the other is estimation of grade of arterial luminal narrowing.
Fatty streaks mostly appeared in the third decade, but the affected area was limited and did not enlarge with age. Fibrous plaque mostly appeared in the fourth decade and increasd in area and severity with advancing age. Narrowing of the coronary arterial lumen by more than 50% was found to become prominent in the sixth decade, reaching the highest level in the seventh and eighth decade. Grade of coronary calcification detected by super-soft X ray had a good correlation with the arterial luminal stenosis. Myocardial infarction is associated with the most severe atherosclerosis.
