title: Preserved coronary flow reserve effectively excludes high-risk coronary artery disease on angiography.
abstract: Myocardial perfusion imaging has limited sensitivity for the detection of high-risk coronary artery disease (CAD). We tested the hypothesis that a normal coronary flow reserve (CFR) would be helpful for excluding the presence of high-risk CAD on angiography.
  
  
  METHODS
  We studied 290 consecutive patients undergoing (82)Rb PET within 180 d of invasive coronary angiography. High-risk CAD on angiography was defined as 2-vessel disease (≥ 70% stenosis), including the proximal left anterior descending artery; 3-vessel disease; or left main CAD (≥ 50% stenosis). Patients with prior Q wave myocardial infarction, elevated troponin levels between studies, prior coronary artery bypass grafting, a left ventricular ejection fraction of less than 40%, or severe valvular heart disease were excluded.
  
  
  RESULTS
  Fifty-five patients (19%) had high-risk CAD on angiography. As expected, the trade-off between the sensitivity and the specificity of the CFR for identifying high-risk CAD varied substantially depending on the cutoff selected. In multivariable analysis, a binary CFR of less than or equal to 1.93 provided incremental diagnostic information for the identification of high-risk CAD beyond the model with the Duke clinical risk score (>25%), percentage of left ventricular ischemia (>10%), transient ischemic dilation index (>1.07), and change in the left ventricular ejection fraction during stress (<2) (P = 0.0009). In patients with normal or slightly to moderately abnormal results on perfusion scans (<10% of left ventricular mass) during stress (n = 136), a preserved CFR (>1.93) excluded high-risk CAD with a high sensitivity (86%) and a high negative predictive value (97%).
  
  
  CONCLUSIONS
  A normal CFR has a high negative predictive value for excluding high-risk CAD on angiography. Although an abnormal CFR increases the probability of significant obstructive CAD, it cannot reliably distinguish significant epicardial stenosis from nonobstructive, diffuse atherosclerosis or microvascular dysfunction.
authors.affiliation: NonInvasive Cardiovascular Imaging Program, Departments of Medicine (Cardiology) and Radiology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Masanao
authors.initials: M
authors.lastname: Naya
authors.forename: Venkatesh L
authors.initials: VL
authors.lastname: Murthy
authors.forename: Viviany R
authors.initials: VR
authors.lastname: Taqueti
authors.forename: Courtney R
authors.initials: CR
authors.lastname: Foster
authors.forename: Josh
authors.initials: J
authors.lastname: Klein
authors.forename: Mariya
authors.initials: M
authors.lastname: Garber
authors.forename: Sharmila
authors.initials: S
authors.lastname: Dorbala
authors.forename: Jon
authors.initials: J
authors.lastname: Hainer
authors.forename: Ron
authors.initials: R
authors.lastname: Blankstein
authors.forename: Frederick
authors.initials: F
authors.lastname: Resnic
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Di Carli
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003251:Constriction, Pathologic / Q000473:pathology; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D003326:Coronary Circulation; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010477:Perfusion; D010496:Pericardium / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods; D011237:Predictive Value of Tests; D011336:Probability; D012372:ROC Curve; D012306:Risk; D012307:Risk Factors; D012414:Rubidium Radioisotopes; D012680:Sensitivity and Specificity; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D012414:Rubidium Radioisotopes
keywords: 82Rb PET; coronary artery disease; coronary flow reserve