Here is an interesting link to an NPR “Science Friday” discussion with a Stanford researcher that points to adult stem cells as the primary cause of plaque generation leading to heart disease.
This still leaves the debate open on what the primary culprit of the vascular injury process actually is. What is injuring the cell lining that leads to stem cell accumulation and the subsequent plaque (i.e. “scar tissue”) formation? It may be that damage to the endothelial cells of the vessels is caused by small-dense LDL particles (apo-B particles – which are likely elevated on a high sugar, refined carb diet) that are oxidized and then start the foam cell process. This inflammatory damage then may spark the stem cells to activate and form a plaque (~scar tissue). I’m no expert though…
Rob Roy's Adventures in Public Health Land! 