title: Quantitative assessment of myocardial perfusion in the detection of significant coronary artery disease: cutoff values and diagnostic accuracy of quantitative [(15)O]H2O PET imaging.
abstract: BACKGROUND
  Recent studies have demonstrated improved diagnostic accuracy for detecting coronary artery disease (CAD) when myocardial blood flow (MBF) is quantified in absolute terms, but there are no uniformly accepted cutoff values for hemodynamically significant CAD.
  
  
  OBJECTIVE
  The goal of this study was to determine cutoff values for absolute MBF and to evaluate the diagnostic accuracy of quantitative [(15)O]H2O positron emission tomography (PET).
  
  
  METHODS
  A total of 330 patients underwent both quantitative [(15)O]H2O PET imaging and invasive coronary angiography in conjunction with fractional flow reserve measurements. A stenosis >90% and/or fractional flow reserve ≤0.80 was considered obstructive; a stenosis <30% and/or fractional flow reserve >0.80 was nonobstructive.
  
  
  RESULTS
  Hemodynamically significant CAD was diagnosed in 116 (41%) of 281 patients who fulfilled study criteria for CAD. Resting perfusion was 1.00 ± 0.25 and 0.92 ± 0.23 ml/min/g in regions supplied by nonstenotic and significantly stenosed vessels, respectively (p < 0.001). During stress, perfusion increased to 3.26 ± 1.04 ml/min/g and 1.73 ± 0.67 ml/min/g, respectively (p < 0.001). The optimal cutoff values were 2.3 and 2.5 for hyperemic MBF and myocardial flow reserve, respectively. For MBF, these cutoff values showed a sensitivity, specificity, and accuracy for detecting significant CAD of 89%, 84%, and 86%, respectively, at a per-patient level and 87%, 85%, and 85% at a per-vessel level. The corresponding myocardial flow reserve values were 86%, 72%, and 78% (per patient) and 80%, 82%, and 81% (per vessel). Age and sex significantly affected diagnostic accuracy of quantitative PET.
  
  
  CONCLUSIONS
  Quantitative MBF measurements with the use of [(15)O]H2O PET provided high diagnostic performance, but both sex and age should be taken into account.
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Danad
authors.affiliation: Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Valtteri
authors.initials: V
authors.lastname: Uusitalo
authors.affiliation: Department of Nuclear Medicine and PET, Institution of Radiology, Oncology and Radiation Science, Institute of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Tanja
authors.initials: T
authors.lastname: Kero
authors.affiliation: Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Saraste
authors.affiliation: Department of Nuclear Medicine & PET Research, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Pieter G
authors.initials: PG
authors.lastname: Raijmakers
authors.affiliation: Department of Nuclear Medicine & PET Research, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Martijn W
authors.initials: MW
authors.lastname: Heymans
authors.affiliation: Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Sami A
authors.initials: SA
authors.lastname: Kajander
authors.affiliation: Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Pietilä
authors.affiliation: Department of Cardiology, Institute of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: James
authors.affiliation: Department of Nuclear Medicine and PET, Institution of Radiology, Oncology and Radiation Science, Institute of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Jens
authors.initials: J
authors.lastname: Sörensen
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Knaapen
authors.affiliation: Turku University Hospital and University of Turku, Turku, Finland. Electronic address: juhani.knuuti@utu.fi.
authors.forename: Juhani
authors.initials: J
authors.lastname: Knuuti
mesh_terms: D000368:Aged; D003251:Constriction, Pathologic; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006321:Heart / Q000000981:diagnostic imaging; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009206:Myocardium / Q000473:pathology*; D010103:Oxygen Isotopes / Q000737:chemistry*; D049268:Positron-Emission Tomography / Q000379:methods*; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D010103:Oxygen Isotopes
keywords: myocardial blood flow; myocardial flow reserve; receiver-operator characteristic curve; sensitivity; specificity