Evidence concerning resistance to atheroma by media-like islands in the intima of coronary arteries

Coronary arteries with and without atheroma are compared histologically to ask what kind of artery encourages atheroma. When atheroma obliterates the structures that preceded and invited its intrusion, the sites remaining for observation form a censored data set. How to assess media-like island effects using the censored data set is the objective here. Full length of right coronary artery is prepared for H&E-stained paraffin sections. At sites lacking atheroma, measurements are taken for intimal thickness (FT), SMC numbers (CT), and their ratio, fibroplastic thickness per SMC, FC = FT/CT. Arteries with atheroma tend to have greater values for all three variables, FC,FT, and CT. Mathematical models compensating for data set censoring imply that atheroma selectively favors sites with much fibroplasia and few SMCs, i.e. high FC. Frequently encountered media-like islands in the coronary intima showed ambiguous evidence of weakly repelling atheroma. Fibroplastic intimal thickening measured by FC progresses relentlessly with age. The sites with the greatest fibroplasia seem to be the most prone to selective obliteration by atheroma. Media-like islands seem to protect only the local sites and not the whole artery from atheroma.