Abstract 12877: Numerical Analysis of the Relationship Between Wall Shear Stress Pattern and Predominant Plaque Localization of the Left Anterior Descending Artery at the Distal Left Main Bifurcation Area
Low wall shear stress(WSS) is associated with plaque development. Plaque lesions distributed in the distal left main coronary artery(LMCA) preferentially propagate to the left anterior descending artery(LAD) rather than to the left circumflex artery(LCX). This phenomenon has been well documented, however, the mechanism is not well understood.
Methods:We used computational fluid dynamics(CFD) to assess the relationship between WSS and plaque distribution at the distal LMCA bifurcation area in 23 consecutive patients with chest pain. Coronary computed tomography was used for the initial screening test followed by coronary angiography and virtual histology intravascular ultrasound(IVUS). Vascular numerical analysis, including WSS, was performed in 6 regions: distal LMCA, proximal LAD, proximal LCX, outer wall of the LMCA to the proximal LAD(zone 1), outer wall of the LMCA to the proximal LCX(zone 2), and the flow divider(zone 3).
Results:Eighteen patients were suitable for WSS analysis. Peak WSS significantly and sequentially decreased between zones 1, 2, and 3(3.1±2.2, 4.8±3.2, 8.9±7.6, p<0.001, respectively). Peak WSS were also significantly decreased, distal to proximal, in the distal LMCA, proximal LAD, and proximal LCX(4.1±2.6, 5.7±4.8, 7.3±5.2, p=0.003, respectively). Persistent lower peak WSS in zone 1 was observed irrespective of plaque type(p<0.001), bifurcation angle(p=0.001), and LCX vessel size(p=0.026)(Table).
Conclusion:Regardless of bifurcation angle degree, plaque type, and LCX vessel size, a significantly lower WSS pattern at zone 1 may contribute to the mechanism of predominant plaque distribution more often found originating in the LCMA and distributing to the proximal LAD rather than the LCX.
- © 2012 by American Heart Association, Inc.