title: [Neointimal tissue proliferation after coronary stent implantation without predilatation].
abstract: OBJECTIVE
  Intravascular ultrasound (IVUS) studies in conventional stent angioplasty with predilatation have demonstrated that late luminal narrowing is caused by neointimal proliferation. In the present study, we analyzed the degree and distribution of in-stent neointimal proliferation after direct stent implantation and aimed to identify variables that predict a proliferative response.
  
  
  METHODS
  We studied 45 patients who underwent successful stent implantation without predilatation and 23 patients with similar clinical and angiographic characteristics who underwent conventional stent angioplasty with predilatation. IVUS imaging was performed at 7.85+/-2.81 months. The cross-sectional area was measured at five predetermined points in the stented coronary segment. The inflation pressure used in patients who underwent direct stent implantation was higher than that employed in those who underwent conventional angioplasty with predilatation (13+/-3 atm vs 10+/-2 atm; P=.005).
  
  
  RESULTS
  Luminal and stent cross-sectional areas were greater in the group that did not undergo predilatation than in the group that did. Neointimal proliferation in the 5 sections analyzed along the axis of the stent was similar in the 2 groups. There was a weak linear relationship between the amount of plaque outside the stent and neointimal proliferation in both the group that underwent predilatation (r=0.37; P=.005) and the group that did not (r=0.33; P=.005).
  
  
  CONCLUSIONS
  As with conventional angioplasty, the neointimal proliferation that occurred after direct stent implantation showed a diffuse homogeneous pattern along the length of the stent. There was a weak correlation between this proliferative response and the amount of plaque outside the stent.
authors.affiliation: Unidad de Hemodinámica y Cardiología Intervencionista, Hospital de la Santa Creu i de Sant Pau, Barcelona, Spain. vmc18461b@hotmail.com
authors.forename: Vicens
authors.initials: V
authors.lastname: Martí
authors.forename: Isabel
authors.initials: I
authors.lastname: Romeo
authors.forename: Fernando
authors.initials: F
authors.lastname: Kozak
authors.forename: Joan
authors.initials: J
authors.lastname: García-Picart
authors.forename: Pere
authors.initials: P
authors.lastname: Guiteras
authors.forename: Juan C
authors.initials: JC
authors.lastname: García-Arriaga
authors.forename: Jordi
authors.initials: J
authors.lastname: Puntí
authors.forename: Josep M
authors.initials: JM
authors.lastname: Augé
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000379:methods; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D003627:Data Interpretation, Statistical; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015607:Stents; D013997:Time Factors; D017539:Tunica Intima / Q000473:pathology*; D018084:Ultrasonography, Interventional