Relationship of shear stress with in-stent restenosis: Bare metal stenting and the effect of brachytherapy

Papafaklis, Michail I.; Bourantas, Christos V.; Theodorakis, Panagiotis E.; Katsouras, Christos S.; Fotiadis, Dimitrios I.; Michalis, Lampros K.

doi:10.1016/j.ijcard.2008.02.006

« Previous Next »International Journal of Cardiology
Volume 134, Issue 1 , Pages 25-32, 1 May 2009

Relationship of shear stress with in-stent restenosis: Bare metal stenting and the effect of brachytherapy

Michail I. Papafaklis
- Michaelideion Cardiac Center, University of Ioannina, Ioannina, Greece
Christos V. Bourantas
- Michaelideion Cardiac Center, University of Ioannina, Ioannina, Greece
Panagiotis E. Theodorakis
- Department of Materials Science and Engineering, University of Ioannina, Ioannina, Greece
Christos S. Katsouras
- Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece
Dimitrios I. Fotiadis
- Michaelideion Cardiac Center, University of Ioannina, Ioannina, Greece
- Department of Computer Science, University of Ioannina, Ioannina, Greece
Lampros K. Michalis
- Michaelideion Cardiac Center, University of Ioannina, Ioannina, Greece
- Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece
- Corresponding author. Department of Cardiology, Medical School, University of Ioannina, University Avenue, Ioannina GR 45110, Greece. Tel.: +30 26510 97710; fax: +30 26510 97017.

Received 27 August 2007; received in revised form 15 January 2008; accepted 27 February 2008. published online 16 June 2008.

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].