title: Frequency of Vascular Inflammation and Impact on Neointimal Proliferation of Drug Eluting Stents in Porcine Coronary Arteries.
abstract: BACKGROUND
  We aimed to describe the frequency of vascular inflammatory reactions with second generation drug eluting stents (DES) compared to first generation DES, and analyze the impact on inflammation and neointimal proliferation in a porcine coronary model.
  
  
  METHODS
  A total of 26 stents (7 multi-link VISION, 6 CYPHER, 6 TAXUS and 7 XIENCE V) were deployed in the coronary arteries of 10 domestic swine for 28 days, after which each stent was harvested and processed (divided into 8 or 9 segments) for histomorphometric analysis.
  
  
  RESULTS
  A total of 202 histological segments [146 DES and 56 bare metal stents (BMS)] were included in this study. The mean neointimal thickness was significantly reduced in the DES group compared to the BMS group. The DES group had higher injury scores (DES = 0.99 ± 0.79 versus BMS = 0.67 ± 0.44, p < 0.004), inflammatory scores (DES = 2.09 ± 1.54 versus BMS = 0.64 ± 0.98, p < 0.001) and presence of para-strut granulomas (DES = 35% versus BMS = 2%, p < 0.001). In logistic regression analysis, the presence of para-strut granulomas correlated with an area of stenosis > 50% (RR: 6.11, 95% CI: 2.97 to 12.59, p = 0.001). In the DES group, the second generation stents had a lower neointimal area (XIENCE V: 1.64 ± 0.90 mm2) compared to the first generation stents (TAXUS: 2.36 ± 1.56 mm2, p = 0.005; CYPHER 2.78 ± 1.82 mm2, p = 0.001). The XIENCE V stents had lower inflammatory scores and lower frequency of para-strut granulomas compared to the first generation stents.
  
  
  CONCLUSIONS
  Second generation DES had a lower incidence of vascular inflammatory reactions compared to first generation DES. This biological phenomenon appears to influence the patterns of neointimal formation.
authors.affiliation: Skirball Center for Cardiovascular Research, Cardiovascular Research Foundation, New York, USA; ; Division of Cardiology, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University; ; Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University Taipei, Taiwan.
authors.forename: Jong Shiuan
authors.initials: JS
authors.lastname: Yeh
authors.affiliation: Skirball Center for Cardiovascular Research, Cardiovascular Research Foundation, New York, USA; ; Division of Cardiology, Department of Internal Medicine, National Health Insurance Corporation, Ilsan Hospital, Seoul, The Republic of Korea.
authors.forename: Seung Jin
authors.initials: SJ
authors.lastname: Oh
authors.affiliation: Department of Ophthalmology, Taipei Medical University Hospital; ; Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chun Mei
authors.initials: CM
authors.lastname: Hsueh
keywords: Drug eluting stent; Porcine coronary artery; Vascular inflammation reaction