Medial thickness of coronary arteries as a correlate of atherosclerosis.

As coronary arteries grow older, they tend to acquire fibroplastic intimal thickenings. Those aging arteries that manifest the greatest fibroplasia are typically the ones that acquire atherosclerotic plaques with necrotic cores (YesA arteries); this is especially so if foam cell infiltration is also extensive. The present study finds that thicker media also distinguishes YesA from NoA specimens. Coronary arteries obtained at autopsy from males and females in eight populations, 16 groups altogether, were evaluated histologically for the YesA characteristics: intimal fibroplasia, foam cell infiltration, and medial thickness. The rankings of the 16 groups at ages 15-29 years persisted significantly into ages 30-69 years when looking at intimal fibroplasia, but not at foam cell infiltration. Medial thickness also yielded youthful population rankings that persisted into older groups, and the rankings were similar to those based on fibroplasia. Virtually all important correlations were obscured if intima:media ratios were employed, because the top and bottom numbers in the ratio typically move in parallel with each other across the meaningful group comparisons, thereby canceling each other.