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This Article Full Text Full Text (PDF) All Versions of this Article: 296/3/H765    most recent 01166.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Torii, R. Articles by Xu, X. Y. Search for Related Content PubMed PubMed Citation Articles by Torii, R. Articles by Xu, X. Y.

Stress phase angle depicts differences in coronary artery hemodynamics due to changes in flow and geometry after percutaneous coronary intervention

¹Department of Chemical Engineering, Imperial College London, ²International Centre for Circulatory Health, National Heart and Lung Institute, Saint Mary's Hospital and Imperial College London, ³Royal Society/Wolfson Medical Image Computing Laboratory, Imperial College London, and ⁴Department of Radiology, Saint Mary's Hospital and Imperial College London, London, United Kingdom

Submitted 8 October 2007 ; accepted in final form 9 January 2009

The effects of changes in flow velocity waveform and arterial geometry before and after percutaneous coronary intervention (PCI) in the right coronary artery (RCA) were investigated using computational fluid dynamics. An RCA from a patient with a stenosis was reconstructed based on multislice computerized tomography images. A nonstenosed model, simulating the same RCA after PCI, was also constructed. The blood flows in the RCA models were simulated using pulsatile flow waveforms acquired with an intravascular ultrasound-Doppler probe in the RCA of a patient undergoing PCI. It was found that differences in the waveforms before and after PCI did not affect the time-averaged wall shear stress and oscillatory shear index, but the phase angle between pressure and wall shear stress on the endothelium, stress phase angle (SPA), differed markedly. The median SPA was –63.9° (range, –204° to –10.0°) for the pre-PCI state, whereas it was 10.4° (range, –71.1° to 25.4°) in the post-PCI state, i.e., more asynchronous in the pre-PCI state. SPA has been reported to influence the secretion of vasoactive molecules (e.g., nitric oxide, PGI₂, and endothelin-1), and asynchronous SPA (–180°) is proposed to be proatherogenic. Our results suggest that differences in the pulsatile flow waveform may have an important influence on atherogenesis, although associated with only minor changes in the time-averaged wall shear stress and oscillatory shear index. SPA may be a useful indicator in predicting sites prone to atherosclerosis.

atherosclerosis; velocity waveform; percutaneous coronary intervention; stress phase angle; computational fluid dynamics