Abstract 17869: Vasomotor Function Following Paclitaxel-Coated Balloon Post-Dilatation in Porcine Coronary Stent Model
Background: Drug-eluting stents (DES) have been associated with impaired endothelial function 6–12 months after stent deployment. It is unclear whether this abnormal vasomotor function is mitigated by reduced duration of exposure to drug release. The purpose of this study was to evaluate endothelial function after post-dilation of bare metal stents with paclitaxel-coated balloons (PCB) or non-drug coated balloons (non-DCB) in a porcine model.
Methods: Thirteen pigs underwent bare-metal stent (BMS) implantation (S/A, 1.1:1; n=30 arteries), followed by post-dilation (B/A, 1.2:1) with either PCB (SeQuent®, n=17) or non-DCB (n=13). Five pigs with unstented, untreated arteries (n=14) were used as controls. Coronary vasomotor function was assessed for all stented arteries one month after implantation, using acetylcholine (Ach) at two doses (10−7 and 10−6 M) and nitroglycerin (NTG, 200 μg). Measurements were obtained for regions of the vessel, as measured from the distal stent edge: 5–10 mm (D1), and 10–15 mm (D2). Animals were terminated for histopathologic and histomorphometric analysis.
Results: Angiographic late loss (p=0.38) and histologic area stenosis (p=0.22) were not different between PCB and non-DCB. However, the % diameter change in response to Ach was significantly diminished with PCB (p<0.05, respectively) at the D1 and D2 regions, when compared with either the non-DCB or naïve arteries. There were no differences between non-DCB and naïve. Histopathology, inflammatory cell infiltration and intramural fibrin deposition were significantly greater after PCB than non-DCB (p<0.05). In addition, the inflammatory response in the stented segment correlated with the degree of % diameter change in response to Ach, at both the D1 and D2 regions.
Conclusions: Post-dilation of BMS with PCB was associated with an impaired vasodilatory response to Ach distal to the treated segments in this pig model. The vasodilatory response after post-dilation with non-DCB was not different than control, naïve arteries. These findings suggest a potential adverse influence of PCB on downstream coronary endothelial function.
- © 2010 by American Heart Association, Inc.