Abstract 18072: Low Endothelial Shear Stress is Associated With High-Risk Coronary Plaque Characteristics in Humans: A Three-Dimensional Frequency-Domain Optical Coherence Tomography Study
Introduction: Large lipid pool and thin fibrous cap are characteristics of plaques at high-risk for rupture resulting in adverse cardiac events. However, the local factors associated with the development of a rupture-prone plaque phenotype are not well known in humans. Endothelial shear stress (ESS) plays a major role in the development and progression of atherosclerotic plaques. We sought to investigate in vivo the relationship between computed ESS and plaque characteristics assessed by frequency-domain optical coherence tomography (FD-OCT).
Methods: Three-dimensional coronary artery reconstruction was performed in 9 patients (4 left anterior descending, 2 left circumflex and 3 right coronary arteries) presenting with acute coronary syndrome using FD-OCT and coronary angiography. Each coronary artery was divided into sequential 3-mm segments, and each segment was analyzed for the assessment of predominant local ESS value by computational fluid dynamics and morphologic characteristics by FD-OCT. A total of 58 non-culprit segments without significant stenosis were evaluated.
Results: Segments with low ESS (<1 Pascal [Pa]) had significantly larger lipid arc (120.9° ± 36.2° vs. 82.5° ± 22.0°, p = 0.015) and thinner fibrous cap (172.7 ± 69.4 μm vs. 264.5 ± 110.5 μm, p = 0.008) compared to segments with higher ESS (≥1 Pa) (Figure). Segments with macrophage accumulation tended to have lower local ESS values (0.98 ± 0.42 Pa vs. 1.62 ± 1.50 Pa, p = 0.170) compared to those without macrophage accumulation. Similarly, segments with lipid-rich plaque (lipid arc >90°) showed lower ESS values compared to those without lipid-rich plaque (1.06 ± 1.02 Pa vs. 1.78 ± 1.54 Pa, p = 0.177).
Conclusions: The present study shows that coronary regions exposed to low ESS are characterized by larger lipid burden and thinner fibrous cap, suggesting that low ESS has a critical role in the development of vulnerable plaques.
- © 2013 by American Heart Association, Inc.