title: Comparison of nonuniform strut distribution between two drug-eluting stent platforms.
abstract: OBJECTIVE
  To compare the difference of strut distribution between two clinically available drug-eluting stent platforms (Bx Velocity and Express II stents) using intravascular ultrasound (IVUS).
  
  
  BACKGROUND
  Nonuniform strut distribution (NSD) has been shown to be associated with increased intimal hyperplasia after drug-eluting stent implantation.
  
  
  METHODS
  IVUS imaging was performed on Bx Velocity (n = 6) and Express II stents (n = 6) after inflation pressures of 10, 16, and 26 atm in a bench test model. Percent NSD was defined as the length of segments with NSD (interstrut angle > 90 degrees) divided by stent length. NSD was also assessed in postprocedure IVUS images in 53 clinical cases (32 Cypher, 21 Taxus) using 3-dimensional IVUS analysis.
  
  
  RESULTS
  Frequency of NSD segment and %NSD were lower in Bx Velocity stents than in Express II stents at the inflation pressures of 16 and 26 atm (%NSD: 16 atm, 0% vs. 13.8 +/- 9.4%; p < 0.005; 26 atm, 1.1 +/- 2.6% vs. 19.9 +/- 6.9% p < 0.0001). In postprocedural images from clinical cases, the frequency of NSD segment and %NSD were lower in Cypher stents than in Taxus stents (%NSD: 0.5 +/- 1.6 vs. 6.8 +/- 7.2; p < 0.0001).
  
  
  CONCLUSIONS
  NSD segment was observed less in Bx Velocity stents than in Express II stents.
authors.affiliation: Center for Research in Cardiovascular Interventions, Stanford University, Stanford, California 94305, USA.
authors.forename: Takao
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Junya
authors.initials: J
authors.lastname: Ako
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Ikeno
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Waseda
authors.forename: Yoriyasu
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Honda
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fitzgerald
mesh_terms: D003331:Coronary Vessels / Q000000981:diagnostic imaging; D006801:Humans; D016014:Linear Models; D008955:Models, Cardiovascular; D011312:Pressure; D011474:Prosthesis Design; D012189:Retrospective Studies; D015607:Stents; D018084:Ultrasonography, Interventional