title: Nonuniform strut distribution correlates with more neointimal hyperplasia after sirolimus-eluting stent implantation.
abstract: BACKGROUND
  Little is known about causes of intimal hyperplasia (IH) after sirolimus-eluting stent (SES) implantation.
  
  
  RESULTS
  Intravascular ultrasound was performed in 24 lesions with intra-SES restenosis and a comparison group of 25 nonrestenotic SESs. To assess stent strut distribution, the maximum interstrut angle was measured with a protractor centered on the stent, and the visible struts were counted and normalized for the number of stent cells. In SES restenosis patients, minimum lumen site was compared with image slices 2.5, 5.0, 7.5, and 10.0 mm proximal and distal to this site. The minimum lumen site had a smaller IVUS lumen area at follow-up (2.7+/-0.9 versus 6.2+/-1.9 mm2; P<0.01), larger maximum interstrut angle (135+/-39 degrees versus 72+/-23 degrees; P<0.01), larger IH area (3.4+/-1.5 versus 0.6+/-1.1 mm2; P<0.01) and thickness (0.7+/-0.3 versus 0.1+/-0.2 mm; P<0.01) at maximum interstrut angle, and fewer stent struts (4.9+/-1.0 versus 6.0+/-0.5; P<0.01) even when normalized for the number of stent cells (0.78+/-0.15 versus 0.97+/-0.07; P<0.01). Compared with nonrestenotic SES, the restenosis lesions also had a smaller minimal lumen area, larger IH area, thicker IH at maximum interstrut angle, fewer stent struts, and larger maximum interstrut angle. Multivariate analysis identified the number of visualized stent struts normalized for the number of stent cells and maximum interstrut angle as the only independent IVUS predictor of IH cross-sectional area (P<0.01 and P<0.01), minimum lumen area (P<0.01 and P<0.01), and IH thickness (P<0.01 and P<0.01).
  
  
  CONCLUSIONS
  The number and distribution of stent struts affect the amount of neointima after SES implantation.
authors.affiliation: Cardiovascular Research Foundation, Lenox Hill Heart and Vascular Institute, New York, NY 10022, USA.
authors.forename: Hideo
authors.initials: H
authors.lastname: Takebayashi
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.forename: Stéphane G
authors.initials: SG
authors.lastname: Carlier
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Fujii
authors.forename: Takenori
authors.initials: T
authors.lastname: Yasuda
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Costa
authors.forename: Issam
authors.initials: I
authors.lastname: Moussa
authors.forename: George D
authors.initials: GD
authors.lastname: Dangas
authors.forename: Roxana
authors.initials: R
authors.lastname: Mehran
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: Lansky
authors.forename: Edward
authors.initials: E
authors.lastname: Kreps
authors.forename: Michael B
authors.initials: MB
authors.lastname: Collins
authors.forename: Antonio
authors.initials: A
authors.lastname: Colombo
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
authors.forename: Martin B
authors.initials: MB
authors.lastname: Leon
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Moses
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000517:prevention & control; D023921:Coronary Stenosis / Q000628:therapy; D004343:Drug Implants; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D006801:Humans; D006965:Hyperplasia; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method; D020123:Sirolimus / Q000008:administration & dosage / Q000627:therapeutic use*; D015607:Stents; D017539:Tunica Intima / Q000000981:diagnostic imaging* / Q000473:pathology; D018084:Ultrasonography, Interventional
chemical_list: D004343:Drug Implants; D020123:Sirolimus