Abstract 13970: Association of Wall Shear Stress with Atherosclerotic Plaque Burden and Composition: A Radiofrequency Intravascular Ultrasound Evaluation in Patients with Coronary Artery Disease
Introduction: Very limited data exist regarding the interplay between coronary wall shear stress (WSS), plaque burden and plaque composition in patients with CAD.Hypothesis: We hypothesized that higher WSS is associated with higher plaque burden, and that lower WSS is associated with greater necrotic core.
Methods: Accordingly, 27 patients with non-obstructive CAD underwent virtual histology intravascular ultrasound (VH-IVUS) and Doppler velocity measurement for computation fluid dynamics modeling to calculate coronary WSS in each VH-IVUS segment (n=3,581, each 0.5mm thickness). External elastic membrane (EEM), plaque, and lumen areas, plaque burden, and plaque composition were derived from VH-IVUS. We assessed the association of WSS with EEM, plaque, and lumen areas, and plaque burden and composition.
Results: The median value of WSS was 23.3 (IQR: 16.5 - 33.5) dynes/cm2 in total segments. Higher WSS was associated with smaller EEM and lumen areas, and greater plaque burden, Table. For each 10% increase in plaque burden, WSS increased 12 dynes/cm2 (p<0.001). After adjusting for plaque burden, for every 10 dynes/cm2 increase in WSS, percent necrotic core decreased by 17% (p=0.01) and percent dense calcium decreased by 17% (p<0.001). There was no significant association between WSS and percent fibrous (p=0.12) and fibro-fatty tissue (p=0.58).
Conclusions: In the largest performed evaluation of the relationship between coronary WSS, plaque burden and plaque composition in patients with CAD, we demonstrate that 1) higher WSS is associated with smaller EEM and lumen areas and greater plaque burden; and 2) after adjusting for plaque burden, lower WSS is associated with greater necrotic core and dense calcium, suggesting that for a given degree of atherosclerosis, lower WSS is associated with more VH-IVUS-defined plaque vulnerability.
- © 2011 by American Heart Association, Inc.