Abstract 3090: The Influence of Shear Stress on Plaque Distribution in Human Coronary Artery Bifurcations assessed with Multi-Slice Computed Tomography
Purpose Early atherosclerosis is located in low wall shear-stress (WSS) regions, however plaques are also found at the flow-dividers or so called carinas of coronary bifurcations, which are exposed to high WSS. We investigated the plaque distribution in bifurcations in relation to the WSS with multi-slice computed tomography angiography (MSCTA).
Methods With 64-slice MSCTA, we inspected in patients both branches of 2 bifurcations for the presence of plaque. For this, we extracted cross-sections 1mm distally to the carina and divided them into four equal parts, which we numbered in ascending order according to expected levels of WSS. Part I covers the outer wall of the bifurcation with the lowest WSS, which increases in part II (inner bend), III (outer bend) and IV (carina).
Results We inspected 65 cross-sections from 28 patients, 98% of whom had plaque in one or more cross-sections. Of all parts I, 72% contained plaque. This percentage was 62%, 38% and 31% in parts II, III and IV, see figure⇓. In 94% of the cross-sections with early atherosclerosis (plaque in 1 or 2 parts) plaque was found in parts I or II. Within a cross-section, parts with plaque were always adjacent. In 93% of the cross-sections where plaque was located at the carina, parts I and/or II also contained plaque. Plaque was never found exclusively in part IV at the carina.
Conclusion Plaque is most present in low WSS regions. Plaque in a high WSS region is accompanied by plaque in the adjacent low WSS regions, indicating that it grows from the outer wall of the bifurcation towards the carina.