Abstract 15037: Effect of the Local Hemodynamic Environment on the De Novo Development and Progression of Eccentric Coronary Atherosclerosis in Humans: A Serial in vivo Vascular Profiling Study
Introduction: Eccentric distribution of atheroma is associated with plaques likely to rupture and cause an acute coronary syndrome, but the factors responsible for the development of eccentricity remain unknown. Endothelial shear stress (ESS) drives plaque formation. We investigated the role of the local hemodynamic environment in the de novo development and progressive worsening of plaque eccentricity in humans.
Methods: Vascular profiling (3-vessel 3D coronary reconstruction by angiography & intravascular ultrasound, and blood flow simulation for ESS computation) was performed in 374 patients at baseline (BL) & 6-10 months follow-up (FU). Each reconstructed artery was divided into consecutive 3-mm segments. At BL, we identified (i) disease-free segments (max plaque thickness <0.5 mm; n=2137), and (ii) diseased regions of luminal narrowings with a throat in the middle surrounded by gradual narrowing upstream and downstream of the throat (n=408). Plaque eccentricity index (EI) was defined as: ratio of max to min plaque thickness.
Results: In disease-free regions, BL low ESS (p<0.001), increased ESS heterogeneity around the circumference of a segment (ratio: max to min ESS; p=0.001), and their interaction (p=0.026) were associated with an increased probability of de novo eccentric plaque formation at FU (max plaque thickness >0.5 mm with plaque EI>2; Fig. A). In diseased regions, BL low ESS (<1 Pa; OR: 2.33, p=0.003) and large plaque burden (>57%; OR: 2.46, p=0.002) were independent predictors of substantially increasing plaque EI with worsening lumen encroachment. The incidence of this combined outcome was higher in narrowings with both features vs all others (33 vs. 12%; p<0.001; Fig. B).
Conclusions: The hemodynamic environment has a critical effect on the development of eccentric coronary plaques at both an early and advanced stage of atherosclerosis. Local ESS assessment may help predict sites of plaque disruption and acute coronary syndromes in humans.
- © 2013 by American Heart Association, Inc.