title: Comparison of paclitaxel-eluting stent and sirolimus-eluting stent expansion at incremental delivery pressures.
abstract: OBJECTIVE
  We sought to compare the adequacy of paclitaxel-eluting stent (PES) and sirolimus-eluting stent (SES) expansion based on intravascular ultrasound (IVUS) imaging criteria at conventional delivery pressures.
  
  
  METHODS
  Forty-six patients underwent SES implantation and 42 patients underwent PES implantation for de novo native coronary lesions<33 mm in length with reference lumen diameters of 2.5-3.5 mm. Stents were serially expanded with gradual balloon inflations at 14 and 20 atm. IVUS imaging was performed prior to intervention and after each balloon inflation. Stent expansion (minimal stent cross-sectional area/reference lumen cross-sectional area) was measured. Inadequate stent expansion was defined using the MUSIC criteria (all struts apposed, no tissue protrusion, and final lumen cross-sectional area>80% of the reference or >90% if minimal lumen cross-sectional area was <9 mm2).
  
  
  RESULTS
  The baseline characteristics of the two groups were similar except for shorter lesion length, larger mean lumen cross-sectional area, larger lumen diameter, and lower plaque burden in the PES group. Stent expansion was inadequate in 80% of patients with SES versus 63% of patients with PES at 14 atm, although this was not statistically significant. After 20 atm, 48% of patients with SES remained underexpanded as compared with 35% of patients with PES.
  
  
  CONCLUSIONS
  Drug-eluting stents showed significant underexpansion by MUSIC criteria at conventionally used inflation pressures. Higher balloon inflations are required especially during deployment of a SES. IVUS guidance is recommended to ensure optimal results and outcomes with both stents.
authors.affiliation: Washington Hospital Center, 110 Irving Street, NW, Suite 4B-1, Washington, DC 20010, USA.
authors.forename: Aamir
authors.initials: A
authors.lastname: Javaid
authors.forename: William W
authors.initials: WW
authors.lastname: Chu
authors.forename: Edouard
authors.initials: E
authors.lastname: Cheneau
authors.forename: Leonardo C
authors.initials: LC
authors.lastname: Clavijo
authors.forename: Lowell F
authors.initials: LF
authors.lastname: Satler
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Kent
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Weissman
authors.forename: Augusto D
authors.initials: AD
authors.lastname: Pichard
authors.forename: Ron
authors.initials: R
authors.lastname: Waksman
mesh_terms: D000368:Aged; D016009:Chi-Square Distribution; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000188:drug therapy*; D016503:Drug Delivery Systems; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D017239:Paclitaxel / Q000008:administration & dosage*; D011312:Pressure; D020123:Sirolimus / Q000008:administration & dosage*; D015607:Stents; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
chemical_list: D007166:Immunosuppressive Agents; D017239:Paclitaxel; D020123:Sirolimus