title: Impact of highly asymmetric stent expansion after sirolimus-eluting stent implantation on twelve-month clinical outcomes.
abstract: OBJECTIVE
  This study investigated the impact of highly asymmetric stent expansion after sirolimus-eluting stent(SES)implantation on clinical outcomes from post procedure to 12 months later.
  
  
  METHODS
  Subjects were 118 patients with 171 lesions who underwent SES implantation for angina pectoris and were studied by intravascular ultrasound (IVUS) following the procedure. The stent symmetry index (minimal stent diameter/maximal stent diameter) at the minimal stent area was calculated by IVUS analysis. The patients were divided into two groups for comparative study: those with stent symmetry index > or = 0.7 were classified into the optimal (O) group (93 patients; 145 lesions, mean age 66 +/- 12 years) and those with stent symmetry index < 0.7 were the sub-optimal (S) group (25 patients; 26 lesions, mean age 67 +/- 10 years).
  
  
  RESULTS
  Angiographic follow up after 8 months showed no differences in target lesion revascularization (TLR) (O group: 3.1% vs S group: 3.8%, p = 0.833). Multivariate analysis identified the post minimal stent diameter as the independent predictor of TLR (p = 0.038). The stent symmetry index < 0.7 was not a predictor of TLR (p = 0.887). Clinical outcomes after 12 months showed both groups had 0% stent thrombosis and there were no differences in deaths (O group: 2.1% vs S group: 4.0%, p = 0.602).
  
  
  CONCLUSIONS
  Highly asymmetric stent expansion after SES implantation may not have a negative impact on clinical outcomes at 12 months.
authors.affiliation: Division of Interventional Cardiology, Cardiovascular Center, Toho University Omori Medical Center, Omori-nishi 6-11-1, Ota-ku, Tokyo 143-8541. toho9686@lily.ocn.ne.jp
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Nakano
authors.forename: Kenji
authors.initials: K
authors.lastname: Wagatsuma
authors.forename: Atsushi
authors.initials: A
authors.lastname: Iga
authors.forename: Hideo
authors.initials: H
authors.lastname: Nii
authors.forename: Hideo
authors.initials: H
authors.lastname: Amano
authors.forename: Mikihito
authors.initials: M
authors.lastname: Toda
authors.forename: Junichi
authors.initials: J
authors.lastname: Yamazaki
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000000981:diagnostic imaging* / Q000601:surgery*; D020099:Coated Materials, Biocompatible; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009204:Myocardial Revascularization; D011379:Prognosis; D012189:Retrospective Studies; D020123:Sirolimus / Q000008:administration & dosage*; D015607:Stents; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
chemical_list: D020099:Coated Materials, Biocompatible; D020123:Sirolimus