title: Clinical significance of fractional flow reserve for evaluation of functional lesion severity in stent restenosis and native coronary arteries.
abstract: OBJECTIVE
  Fractional flow reserve (FFR) is a valid surrogate for hemodynamic significance in stenotic native coronary arteries, but its validity in patients with coronary stent restenosis is unknown.
  
  
  METHODS
  Prospective.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  We studied 42 patients (mean age +/- 1 SD, 62 +/- 10 years) with stent restenosis and 57 patients (mean age, 61 +/- 12 years) with a native coronary lesion. All patients demonstrated a single coronary lesion of intermediate severity (stenosis diameter, 40 to 70%). Determination of FFR and quantitative angiography of the stenosis were performed.
  
  
  RESULTS
  Stenosis diameter was comparable in both groups (native, 52 +/- 11%; stent, 52 +/- 9%; not significant [NS]). FFR was lower in stent restenosis (0.77 +/- 0.15 vs 0.82 +/- 0.12, p < 0.05) and more often pathologic with an FFR < 0.75 (48% vs 26%, p < 0.05) compared to native coronary stenosis. However, the area under the receiver operating characteristic curve for native stenosis was 0.82 (95% confidence interval [CI], 0.71 to 0.94) and for stent restenosis was 0.84 (95% CI, 0.71 to 0.97; NS). In patients with an FFR > 0.75, there was no adverse coronary event that was related to the stented lesion in the subsequent 6 months.
  
  
  CONCLUSIONS
  The threshold of stenosis diameter of coronary lesions for pathologic FFR measurement (FFR < 0.75) is similar for stent restenosis and native coronary stenosis. Thus, FFR measurement seems to be applicable for decision making in patients with stent restenosis.
authors.affiliation: Medical Clinic I, University Hospital, University of Technology, Aachen, Germany. skrueger@lukasneuss.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Krüger
authors.forename: Karl-Christian
authors.initials: KC
authors.lastname: Koch
authors.forename: Ira
authors.initials: I
authors.lastname: Kaumanns
authors.forename: Marc W
authors.initials: MW
authors.lastname: Merx
authors.forename: Peter
authors.initials: P
authors.lastname: Hanrath
authors.forename: Rainer
authors.initials: R
authors.lastname: Hoffmann
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D001794:Blood Pressure; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015607:Stents / Q000009:adverse effects*