title: Relative coronary flow velocity reserve improves correlation with stress myocardial perfusion imaging in assessment of coronary artery stenoses.
abstract: OBJECTIVE
  To evaluate the angiographic and coronary flow velocity parameters that best correlate with the results of stress myocardial perfusion imaging.
  
  
  METHODS
  Criterion standard.
  
  
  METHODS
  Tertiary care center.
  
  
  METHODS
  Forty-eight patients undergoing diagnostic coronary angiography for angina or silent ischemia.
  
  
  METHODS
  We performed angiographic and coronary flow velocity measurements at rest and during hyperemia at the post-stenotic segment and in the adjacent angiographically normal branch of the left coronary artery. Relative coronary flow velocity reserve (RCFVR) was calculated as the ratio of post-stenotic to reference vessel coronary flow velocity reserve (CFVR). The best cutoff points for reversible perfusion defects were calculated using receiver operating characteristic curves.
  
  
  RESULTS
  Post-stenotic CFVR showed fairly good correlations with minimal lumen diameter and percentage of diameter stenosis (r = 0.57 and r = 0.55, respectively; p < 0.001). RCFVR showed stronger correlations with these angiographic indexes of stenosis severity (r = 0.66 and r = 0.68, respectively; p < 0.0001). Based on receiver operating characteristic cutoff values (1.67 for post-stenotic CFVR and 0.64 for RCFVR), RCFVR had better agreement with myocardial perfusion imaging results, compared to post-stenotic CFVR (92% vs 75%, respectively). This agreement was more meaningful in patients with moderate coronary artery stenoses (50 to 75%). The area under the curve was 0.65 (not significant) for post-stenotic CFVR and 0.88 (p < 0.01) for RCFVR.
  
  
  CONCLUSIONS
  RCFVR describes better than post-stenotic CFVR the functional significance of coronary artery stenoses.
authors.affiliation: First Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece. vvoudris@otenet.gr
authors.forename: Vassilis
authors.initials: V
authors.lastname: Voudris
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Avramides
authors.forename: Maria
authors.initials: M
authors.lastname: Koutelou
authors.forename: John
authors.initials: J
authors.lastname: Malakos
authors.forename: Athanasios
authors.initials: A
authors.lastname: Manginas
authors.forename: Manolis
authors.initials: M
authors.lastname: Papadakis
authors.forename: Dennis V
authors.initials: DV
authors.lastname: Cokkinos
mesh_terms: D001783:Blood Flow Velocity; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index