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Abstract: Background: The association of shear stress (SS) with in-stent restenosis after bare metal stenting is not clear. We investigated the significance of SS on predicting areas with neointima thickness (NT) in humans and the effect of vascular brachytherapy (VBT) following coronary artery stenting on the relationship of SS with NT. Methods: By using coronary angiography and intravascular ultrasound, we performed three-dimensional (3D) artery and stent reconstruction in 14 patients at 8-month follow-up after bare metal stenting with (stent&VBT group; 7 patients) or without (stent group; 7 patients) adjunctive beta-VBT. In-stent SS was calculated by applying computational fluid dynamics to the stent reconstruction and NT was determined in 3D space. Results: NT was significantly increased in the stent group (0.2±0.16 mm vs. 0.07±0.18 mm, p <0.001). The estimated intercepts and slopes regarding the relationship of NT with SS were 0.28 mm [95% confidence interval (CI): 0.20 to 0.36 mm, p <0.001] and −0.057 mm/Pa (95% CI: −0.062 to −0.052 mm/Pa, p <0.001) respectively for the stent group, and 0.15 mm (95% CI: −0.02 to 0.31 mm, p =0.082) and −0.017 mm/Pa (95% CI: −0.023 to −0.010 mm/Pa, p <0.001) respectively for the stent&VBT group. After pooling all data together, a significant effect of VBT on the relationship between NT and SS was found [estimate of interaction term (group×SS) for stent&VBT vs. stent group: 0.04 mm/Pa; 95% CI: 0.032 to 0.049 mm/Pa, p <0.001]. Conclusions: In-stent restenosis is inversely related to SS after coronary artery stenting and VBT diminishes the inverse relationship between NT and SS. [Copyright &y& Elsevier]

Abstract: We report for the first time a real three-dimensional reconstruction of the left main coronary artery, left main bifurcation, left anterior descending coronary artery and left circumflex coronary artery using biplane angiography and intravascular ultrasound imaging in a patient with a proximal stenosis in the left anterior descending coronary artery. By using computational fluid dynamics in the three-dimensional luminal model we computed endothelial shear stress, while plaque thickness was calculated as the difference between the three-dimensional lumen and outer vessel wall; plaque thickness was found to be inversely related to endothelial shear stress in the left main coronary artery and bifurcation. The application of our methodology for real three-dimensional reconstruction of the left main coronary artery and bifurcation is useful for investigating the relationship of hemodynamic parameters with plaque thickness in this critical coronary region. [Copyright &y& Elsevier]