Wahle A, Lopez JJ, Olszewski ME, Vigmostad SC, Braddy KC, Brennan TMH, Bokhari SW, Bennett JG, Holper EM, Rossen JD, Chandran KB, Sonka M:


Inverse Relationship between Local Wall Shear Stress and Plaque Thickness in Coronary Arteries is Retained by Compensatory Enlargement in Early Atherosclerosis.

American College of Cardiology, 54th Scientific Sessions, Orlando FL, Journal of the ACC, Suppl.

Volume 45, Number 3/A, Page 416A, Abstract 1126-138, February 2005

Analysis on plaque-distribution/wall-shear-stress distribution with automated consideration of local disease severity (Poster) (Links)

Abstract: Background - In coronary arteries, it is hypothesized that areas of low wall shear stress (WSS) are associated with increasing plaque thickness (PT) during atherosclerotic progression. This dynamic relationship cannot be observed directly, since obstructive plaque development affects WSS distribution. Therefore, we investigated if this relationship could be seen in areas of compensatory enlargement (outward remodeling) without luminal narrowing, thus representing the pre-disease WSS. We determined the point of atherosclerotic disease progression at which the inverse relationship diminishes. Methods - 39 in-vivo intravascular-ultrasound (IVUS) pullbacks (16 LAD, 8 LCX, 15 RCA) from 22 male and 9 female patients were reconstructed by geometrically correct 3-D fusion with X-ray angiography, and computational fluid dynamics methods were employed. After excluding branches, calcified and stented regions, a total of 3,046 cross sections were automatically analyzed; of these, 1,357 were within the 10-40% area-stenosis range (plaque+media area over vessel area) associated with compensatory enlargement. WSS and PT were calculated at 72 circumferential locations within each cross section, and for each location the existence of an inverse WSS/PT relationship was assessed. Results - In 24 of 39 vessels, at least 35% of the cross sections were in the compensatory-enlargement range. In 18 of those vessels (75%), inverse WSS/PT relationships were observed significantly more frequently in the segments within the compensatory-enlargement range than in the vessel as a whole (p<0.005). When also including the 15 vessels with less than 35% of the cross sections within the compensatory-enlargement range, a statistical difference in inverse-relationship presence was no longer observed (p>0.4). Conclusions - The inverse relationship between WSS and PT is significantly more pronounced in vessel cross sections within the compensatory-enlargement range as compared to the full spectrum of vessel stenosis severity. If less than 35% of a vessel segment remains without luminal narrowing, thus advanced atherosclerosis, the strength of this inverse relationship diminishes and is no longer significant.

Please note that the poster contains the full abstract text, updated with results from additional patients