Prediction of the Localization of High-Risk Coronary Atherosclerotic Plaques on the Basis of Low Endothelial Shear Stress An Intravascular Ultrasound and Histopathology Natural History Study

Background— Low endothelial shear stress (ESS) promotes the development of atherosclerosis; however, its role in the progression of atherosclerotic plaques and evolution to inflamed high-risk plaques has not been studied. Our hypothesis was that the lowest values of ESS are responsible for the development of high-risk coronary atherosclerotic plaques associated with excessive expansive remodeling. Methods and Results— Twenty-four swine, treated with streptozotocin to induce diabetes and fed a high-fat diet, were allocated into early (n=12) and late (n=12) atherosclerosis groups. Intima-media thickness was assessed by intravascular ultrasound in the coronary arteries at weeks 4 and 8 in the early group and weeks 23 and 30 in the late group. Plaques started to develop after week 8, leading to marked heterogeneity in plaque severity at week 30. ESS was calculated in plaque-free subsegments of interest (n=142) in the late group at week 23. Coronary arteries (n=31) of this group were harvested at week 30, and ...