Abstract 17559: Endothelial Shear Stress Magnitude and Circumferential Heterogeneity Predict the Localization of Eccentric Coronary Atherosclerotic Plaques in Humans
Introduction: Lesion eccentricity is associated with plaque vulnerability leading to acute coronary events. Endothelial shear stress (ESS) exhibits remarkable heterogeneity over short distances and critically determines local plaque formation/progression. The factors responsible for atherosclerosis onset with augmented plaque eccentricity are not known. We tested the hypothesis that ESS magnitude and circumferential heterogeneity (ESS-CH) dictate the localization of eccentric atherosclerotic lesions in humans.
Methods: 3D coronary artery reconstruction by angiography & intravascular ultrasound was performed in 374 pts at baseline (BL) and 6-10 months later (FU) to explore plaque natural history. 874 arteries were divided into consecutive 3-mm segments. 2,157 minimally diseased segments (max plaque thickness ≤ 0.5 mm) at BL were analyzed. Local BL ESS was assessed by computational fluid dynamics and ESS-CH within each segment was determined as the ratio of max to min ESS. Progressive eccentric plaque formation (n=427; 19.8%) was defined as plaque eccentricity index (ratio: max to min plaque thickness) >2 at FU with a temporal increase in the eccentricity index.
Results: Segments with progressive eccentric plaque formation had an increase in plaque area (%change: 16.3±2.7 vs. 3.4±0.7%, p<0.001) compared to all others. BL low ESS (p=0.019) and high ESS-CH (p=0.026) were independent predictors of progressive eccentric plaque formation (Fig. A). The incidence of progressive eccentric plaque formation (Fig. B) was 30% in the presence of both low ESS and high ESS-CH vs. 19% without this combination of characteristics (OR=1.9 [95% CI: 1.3-2.8], p=0.001).
Conclusions: Low ESS and high ESS-CH each exert an independent effect on progressive eccentric lesion formation. Coronary regions culminating in a rupture-prone phenotype, i.e. at highest risk to cause an adverse event, can be identified early by assessment of hemodynamic and plaque characteristics.
- Vulnerable plaque
- Intravascular ultrasound/Doppler
- Coronary artery disease
- © 2012 by American Heart Association, Inc.