Coronary intimal necrosis occurring as an early stage of atherosclerotic involvement

In a population sample in whom violent accident was the cause of death, the following prevalence of coronary intimal necrosis, occurring as an independent lesion and as an early step of atherosclerotic involvement, was revealed: 2% of children 6--10 years old, 6% of children and juveniles 11--15 years old, 14% of adolescents 16--20 years old, 32% of young adults 21--25 years old, 56% of young adults 26--30 years old, 72% of mature adults 31--35 years old and 84% of mature adults 36--40 years old. In each age subgroup, the percentage of subjects with coronary intimal necrosis was greater than the percentage of subjects with coronary atherosclerotic plaques. A centrifugal extension with age of intimal necrosis, along the coronary tree in the direction of blood flow, was observed. Histologically, the coronary intimal necrosis exhibited a mucoid form, a swelling form and a dissecting form. Indirect evidence was offered that some areas of coronary intimal necrosis formed an adequate nidus for lipid and fibrin accumulation and also induced the development of a peculiar type of subendothelial connective tissue. These successive changes led to the onset of atheroma-like lesions with a prevalence of lipid deposits, or of intramural thrombi or of a fibro-hyaline cap. The onset, extent and evolution of coronary intimal necrosis was accelerated by the male sex, by some minor deviations from the basal branching anatomical pattern of the coronary arteries, by the main risk factors for coronary heart disease, as well as by some terminal diseases, such as the generalized form of sarcoidosis and the renal complications of systemic lupus erythematosus.