Abstract 20255: New Polymer-Free Everolimus-Eluting Stent Using Nitrogen-Doped Titanium Dioxide Film in a Porcine Coronary Model: Micro-Computed Tomography, Optical Coherence Tomography, and Histopathological Analysis
Background: Titanium dioxide (TiO2) films have been shown to be highly biocompatible and effective as drug-binding matrices for drug-eluting stents (DES). We sought to assess the efficacy of a new polymer-free everolimus-eluting stent (EES) using nitrogen-doped TiO2 film deposited onto a new bare-metal stent (BMS, CNUH (Tiger®) stent) we recently developed in a porcine coronary restenosis model.
Methods: A total of 40 coronary arteries in 20 pigs were randomly allocated to group 1 [CNUH (Tiger®) stent (CG Bio Inc., Jangseong, Republic of Korea), 3.0х18 mm, n = 10], group 2 [CNUH (Tiger®) stent with nitrogen-doped TiO2 film deposition, 3.0х18 mm, n = 10], group 3 [commercial durable-polymer EES (Xience Prime®, Abbott Vascular, Santa Clara, CA, USA), 3.0х18 mm, n = 10], and group 4 [polymer-free EES using nitrogen-doped TiO2 film deposition on CNUH (Tiger®) stent, 3.0х18 mm, n = 10]. Stents were randomly implanted in the left anterior descending coronary artery and left circumflex artery with stent: artery ratio of 1.3. Four weeks later, pigs underwent follow-up coronary angiography and were sacrificed for imaging and histopathological analysis.
Results: On histopathological analysis, area stenosis rate was higher in group 1 compared to group 3 and 4 (46.4±13.8% vs. 30.2±11.7% vs. 29.2±8.9%, respectively, p = 0.005). Fibrin score was lower in groups 1 and 2, compared to groups 3 and 4: 0.87±0.67 vs. 0.76±0.61 vs. 2.27±0.24 vs. 1.75±0.31, respectively, p<0.001). Comparison between DES showed lower fibrin score in group 4 than group 3 (1.75±0.31 vs. 2.27±0.24, p = 0.023). Immunofluorescence staining with CD68 showed lower inflammation in group 4 compared to group 3. Micro-computed tomography scan showed similar restenosis rate between groups 3 and 4: 16.5±3.3% vs. 15.6±1.0%, p = 0.736. Optical coherence tomography study revealed no difference between groups 3 and 4 in the lumen area (2.2±1.4 mm2 vs. 3.0±0.03 mm2, p = 0.503), stent area (3.7±0.2 mm2 vs. 3.8±0.2 mm2, p = 0.679), and percent neointimal area (37.9±3.8% vs. 20.2±4.3%, p = 0.517).
Conclusions: In a porcine model of coronary restenosis, polymer-free EES using nitrogen-doped TiO2 film showed higher biocompatibility and compared favorably with a commercial durable-polymer EES.
Author Disclosures: D. Sim: None. M. Kim: None. M. Jeong: None. D. Park: None. J. Kim: None. K. Lim: None. I. Bae: None. P. Zhehao: None. H. Yang: None. J. Lee: None. D. Hyun: None. Y. Hong: None. J. Kim: None. Y. Ahn: None. J. Kang: None.
- © 2016 by American Heart Association, Inc.