title: Influence of a pressure gradient distal to implanted bare-metal stent on in-stent restenosis after percutaneous coronary intervention.
abstract: BACKGROUND
  Fractional flow reserve predicts cardiac events after coronary stent implantation. The aim of the present study was to assess the 9-month angiographic in-stent restenosis rate in the setting of optimal stenting and a persisting gradient distal to the stent as assessed by a pressure wire pullback recording in the entire length of the artery.
  
  
  RESULTS
  In 98 patients with angina pectoris, 1 de novo coronary lesion was treated with a bare-metal stent. After stent implantation, pressure wire measurements (P(d)=mean hyperemic coronary pressure and P(a)=mean aortic pressure) were performed in the target vessel: (1) P(d)/P(a) as distal to the artery as possible (fractional flow reserve per definition); (2) P(d)/P(a) just distal to the stent; (3) P(d)/P(a) just proximal to the stent; and (4) P(d)/P(a) at the ostium. Residual abnormal P(d)/P(a) was defined as a pressure drop between P(d)/P(a) measured at points 1 and 2. Fractional flow reserve distal to the artery after stenting was significantly lower (0.88+/-0.21 versus 0.97+/-0.05; P<0.001), and angiographic in-stent binary restenosis rate was significantly higher (44.0% versus 8.1%; P<0.001) in vessels with a residual abnormal P(d)/P(a). Residual abnormal P(d)/P(a) (odds ratio, 4.39; 95% confidence interval, 1.10 to 18.16; P=0.034), reference vessel size (odds ratio, 0.17; 95% confidence interval, 0.04 to 0.69; P=0.013), and stent length (odds ratio, 1.11; 95% confidence interval, 1.03 to 1.21; P=0.009) were predictors of angiographic in-stent restenosis after 9 months.
  
  
  CONCLUSIONS
  A residual abnormal P(d)/P(a) distal to a bare-metal stent was an independent predictor of in-stent restenosis after implantation of a coronary bare-metal stent.
authors.affiliation: Department of Cardiology, Catheterization Laboratory, Odense University Hospital, Sdr Blvd 29, 5000 Odense C, Denmark. okkels@dadlnet.dk
authors.forename: Lisette Okkels
authors.initials: LO
authors.lastname: Jensen
authors.forename: Per
authors.initials: P
authors.lastname: Thayssen
authors.forename: Leif
authors.initials: L
authors.lastname: Thuesen
authors.forename: Henrik Steen
authors.initials: HS
authors.lastname: Hansen
authors.forename: Jens Flensted
authors.initials: JF
authors.lastname: Lassen
authors.forename: Henning
authors.initials: H
authors.lastname: Kelbaek
authors.forename: Anders
authors.initials: A
authors.lastname: Junker
authors.forename: Knud Noerregaard
authors.initials: KN
authors.lastname: Hansen
authors.forename: Hans Erik
authors.initials: HE
authors.lastname: Boetker
authors.forename: Lars Romer
authors.initials: LR
authors.lastname: Krusell
authors.forename: Knud Erik
authors.initials: KE
authors.lastname: Pedersen
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D001157:Arterial Occlusive Diseases / Q000628:therapy; D001794:Blood Pressure / Q000502:physiology*; D003326:Coronary Circulation / Q000502:physiology*; D023903:Coronary Restenosis / Q000453:epidemiology* / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000628:therapy; D012189:Retrospective Studies; D015607:Stents