Impact of stent implantation on endothelial shear stress.

BACKGROUND: Endothelial shear stress (ESS) may play a key role in the pathobiology of stent restenosis (SR). Nevertheless, limited data are available about ESS and its relation to SR.

PATIENTS AND METHODS: We enrolled 14 patients who underwent successful percutaneous coronary intervention (PCI) in this study. Three-dimensional (3D) reconstruction of 14 coronary arteries before and after stent implantation was performed. Using computational fluid dynamics, mean ESS was calculated proximally, in tertiles within and distal to the stent, both before and after stent implantation.

RESULTS: Stent implantation resulted in a significant ESS decrease in the entire atherosclerotic lesion (1.83 vs. 1.26 Pa, p = 0.02). Regarding the five territories in which the entire lesion was divided, ESS decrease was marginally significant in the area of the second in-stent tertile, and in the area 5 mm distal to the stent, whereas ESS decrease was not significant in the area 5 mm proximal to the stent, and in the area of the first and third in-stent tertile. At 12 months, two patients had SR, but restenosis was not related to ESS decrease.

CONCLUSION: ESS decreases after stent implantation but not uniformly, with the major reduction being in the middle tertile of the stent, and distal to the stent. In-stent ESS decrease may create local hemodynamic conditions leading to in-stent and in-segment restenosis.