title: Serial intravascular ultrasound analysis of stent strut distribution and fracture: an integrated analysis of the taxus IV, V, and VI trials.
abstract: OBJECTIVE
  Non-uniform distribution of drug-eluting stent struts may cause uneven drug deposition associated with an adverse neointimal response and clinical events. This study assesses circumferential stent strut distribution in bare-metal (BMS) and paclitaxel-eluting (Taxus) stents post implantation and at 9-month follow-up, as well as its impact on intimal hyperplasia (IH).
  
  
  RESULTS
  In the current analysis, intravascular ultrasound (IVUS) substudies of the Taxus IV, V, and VI trials were combined. Among them, 242 stents (117 BMS and 125 Taxus) had paired IVUS images post procedure and at 9-month follow-up that were reassessed at 1 mm intervals. Post implantation, the maximum interstrut angle (71.5 ± 17.7° vs 70.0 ± 19.6°; P=.53) and minimum number of stent struts (7.1 ± 1.0 vs 7.2 ± 0.8; P=.32) were similar in Taxus vs BMS subgroups, respectively. At 9-month follow-up, the maximum angle increased (92.8 ± 22.1° and 81.7 ± 20.6°) and stent strut numbers decreased (6.1 ± 0.9 and 6.5 ± 1.0) for both Taxus and BMS, respectively, as compared to immediately post implantation (all P<.001). The increased stent angle was more pronounced for Taxus compared with BMS (P<.01). Non-uniform strut distribution did not affect IH pattern or clinical outcomes in either stent population. No complete stent fractures were identified.
  
  
  CONCLUSIONS
  Stent strut distribution changed from implantation to follow-up with an increased interstrut angle and fewer visible stent struts. These changes were more pronounced for Taxus as compared to BMS; however, non-uniform strut distribution was unrelated to increased IH or clinical outcomes.
authors.affiliation: National Institute of Cardiology, Coronary and Structural Heart Diseases Dept. 2nd Floor, 42 Alpejska St, 04-628 Warsaw, Poland. radekpracon@yahoo.pl.
authors.forename: Radoslaw
authors.initials: R
authors.lastname: Pracon
authors.forename: Maksymilian P
authors.initials: MP
authors.lastname: Opolski
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.forename: Jerzy
authors.initials: J
authors.lastname: Pregowski
authors.forename: Mariusz
authors.initials: M
authors.lastname: Kruk
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Popma
authors.forename: Lazar
authors.initials: L
authors.lastname: Mandinov
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Ellis
authors.forename: Eberhard
authors.initials: E
authors.lastname: Grube
authors.forename: Keith D
authors.initials: KD
authors.lastname: Dawkins
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Weissman
mesh_terms: D000368:Aged; D015331:Cohort Studies; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000628:therapy*; D004311:Double-Blind Method; D054855:Drug-Eluting Stents; D004868:Equipment Failure; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000000981:diagnostic imaging*; D017239:Paclitaxel / Q000008:administration & dosage*; D011446:Prospective Studies; D017539:Tunica Intima / Q000000981:diagnostic imaging* / Q000187:drug effects* / Q000473:pathology; D018084:Ultrasonography, Interventional
chemical_list: D017239:Paclitaxel