Influence of Arterial Pressure on a Model for Cholesterol Accumulation and Intimal Growth

Abstract

Cardiovascular diseases are among the first causes of death in the first world countries nowadays, and are expected to be among them in the developing countries in the near future. Atherosclerosis, one of the main cardiovascular diseases, is a chronic inflammatory disease that affects medium and great
size arteries by means of an accumulation of fat, cholesterol, cell debris, calcium and smooth muscle cells in the artery wall. This accumulation may lead to the formation of atherosclerotic plaques, called atheromas, which could either grow towards the lumen of the artery or become unstable and rupture, causing a partial or total obstruction of the blood flow. The lack of blood supply to an organ implies the lack
of oxygen causing its temporary mal functioning (ischemia) or the death of the tissue (infarct). Since late seventies it has been hypothesized that hemodynamic forces over the endothelium, the innermost layer of arteries, are very important to the formation and development of atheromas. This hypothesis suggests that atheromas grow in regions of complex flow patterns, such as bifurcations or regions of
marked curvature, where recirculation and/or secondary flow develops. Among others, arterial pressure and cholesterol concentration in blood are some important known factors that influence the development of the atherosclerotic plaques. In this work we study the influence of the arterial pressure on the intimal growth rate predicted by a model developed by the authors and presented in previous works. We selected
for this study a model of the carotid bifurcation in the carotid artery, which has received and continues to receive a lot of attention for it supplies blood to some parts of the brain. Atheromas that develop in this bifurcation may cause a stroke, which is one of the major causes of death. In the present work we use this model, combined with Finite Volume simulations of the blood flow through the artery, to study the influence of arterial pressure on the time evolution and shape of an atheroma developed in this bifurcation.