Coronary Artery Wall Shear Stress Is Associated With Progression and Transformation of Atherosclerotic Plaque and Arterial Remodeling in Patients With Coronary Artery Disease

Abstract

Background: Experimental studies suggest that low wall shear stress (WSS) promotes plaque development and high WSS is associated with plaque destabilization. We hypothesized that low-WSS segments in patients with coronary artery disease develop plaque progression and high-WSS segments develop necrotic core progression with fibrous tissue regression. Methods and Results: Twenty patients with coronary artery disease underwent baseline and 6-month radiofrequency intravascular ultrasound (virtual histology intravascular ultrasound) and computational fluid dynamics modeling for WSS calculation. For each virtual histology intravascular ultrasound segment (n=2249), changes in plaque area, virtual histology intravascular ultrasound–derived plaque composition, and remodeling were compared in low-, intermediate-, and high-WSS categories. Compared with intermediate-WSS segments, low-WSS segments developed progression of plaque area ( P =0.027) and necrotic core ( P <0.001), whereas high-WSS segments had progression of necrotic core ( P <0.001) and dense calcium ( P <0.001) and regression of fibrous ( P <0.001) and fibrofatty ( P <0.001) tissue. Compared with intermediate-WSS segments, low-WSS segments demonstrated greater reduction in vessel ( P <0.001) and lumen area ( P <0.001), and high-WSS segments demonstrated an increase in vessel ( P <0.001) and lumen ( P <0.001) area. These changes resulted in a trend toward more constrictive remodeling in low- compared with high-WSS segments (73% versus 30%; P =0.06) and more excessive expansive remodeling in high- compared with low-WSS segments (42% versus 15%; P =0.16). Conclusions: Compared with intermediate-WSS coronary segments, low-WSS segments develop greater plaque and necrotic core progression and constrictive remodeling, and high-WSS segments develop greater necrotic core and calcium progression, regression of fibrous and fibrofatty tissue, and excessive expansive remodeling, suggestive of transformation to a more vulnerable phenotype. Clinical Trial Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT00576576.