title: Intravascular ultrasound assessment of drug-eluting stent expansion.
abstract: BACKGROUND
  In the drug-eluting stent (DES) era, stent expansion remains an important predictor of restenosis and subacute thrombosis. Compliance charts are developed to predict final minimum stent diameter (MSD) and area (MSA). The objectives of the study were (1) to assess DES expansion by comparing intravascular ultrasound (IVUS)-measured MSD and MSA against the values predicted by compliance charts and (2) to compare each DES against its bare-metal stent (BMS) equivalent.
  
  
  METHODS
  We enrolled 200 patients with de novo coronary lesions treated with single, >2.5-mm Cypher (Cordis, Johnson & Johnson, Miami Lakes, FL) (sirolimus-eluting stent [SES], 133 patients) or Taxus (Boston Scientific, Natick, MA) (paclitaxel-eluting stent [PES], 67 patients) stent under IVUS guidance without another postdilation balloon. We used a comparison cohort of 65 equivalent BMS (Express 2 [Boston Scientific], 37 patients; Bx Velocity [Cordis, Johnson & Johnson], 28 patients) deployed under similar conditions.
  
  
  RESULTS
  The DES achieved only 75% +/- 10% of predicted MSD and 66% +/- 17% of predicted MSA; this was similar for SES and PES. Furthermore, 24% of SES and 28% of PES did not achieve a final MSA of 5 mm(2), a consistent predictor of DES failure. The SES achieved 75% +/- 10% of predicted MSA versus 75% +/- 9% for Bx Velocity (P = .9). The PES achieved 79.9% +/- 14% of predicted MSA versus 79% +/- 10% for Express 2 (P = .8). Lesion morphology, arc and length of calcium, stent diameter and length, and implantation pressures did not affect expansion.
  
  
  CONCLUSIONS
  Compliance charts fail to predict final MSD and MSA. A considerable percentage of DES does not achieve minimum standards of stent expansion. The SES and PES achieve similar expansion to their BMS platform, indicating that the polymer coating does not affect DES expansion in vivo. However, stent expansion cannot be predicted from preintervention IVUS lesion assessment.
authors.affiliation: Cardiovascular Research Foundation and Columbia University Medical Center, New York, NY, USA.
authors.forename: Jose
authors.initials: J
authors.lastname: de Ribamar Costa
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.forename: Stéphane G
authors.initials: SG
authors.lastname: Carlier
authors.forename: Kenichi
authors.initials: K
authors.lastname: Fujii
authors.forename: Koichi
authors.initials: K
authors.lastname: Sano
authors.forename: Masashi
authors.initials: M
authors.lastname: Kimura
authors.forename: Kaoru
authors.initials: K
authors.lastname: Tanaka
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Costa
authors.forename: Joanna
authors.initials: J
authors.lastname: Lui
authors.forename: Yingbo
authors.initials: Y
authors.lastname: Na
authors.forename: Celia
authors.initials: C
authors.lastname: Castellanos
authors.forename: Sinan
authors.initials: S
authors.lastname: Biro
authors.forename: Issam
authors.initials: I
authors.lastname: Moussa
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Moses
authors.forename: Martin B
authors.initials: MB
authors.lastname: Leon
mesh_terms: D023903:Coronary Restenosis / Q000517:prevention & control; D023921:Coronary Stenosis / Q000628:therapy*; D016503:Drug Delivery Systems; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D015607:Stents; D018084:Ultrasonography, Interventional