title: Does quantification of myocardial flow reserve using rubidium-82 positron emission tomography facilitate detection of multivessel coronary artery disease?
abstract: BACKGROUND
  Relative myocardial perfusion imaging (MPI) is the standard imaging approach for the diagnosis and prognostic work-up of coronary artery disease (CAD). However, this technique may underestimate the extent of disease in patients with 3-vessel CAD. Positron emission tomography (PET) is also able to quantify myocardial blood flow. Rubidium-82 ((82)Rb) is a valid PET tracer alternative in centers that lack a cyclotron. The aim of this study was to assess whether assessment of myocardial flow reserve (MFR) measured with (82)Rb PET is an independent predictor of severe obstructive 3-vessel CAD.
  
  
  METHODS
  We enrolled a cohort of 120 consecutive patients referred to a dipyridamole (82)Rb PET MPI for evaluation of ischemia neither with prior coronary artery bypass graft nor with recent percutaneous coronary intervention that also underwent coronary angiogram within 6 months of the PET study. Patients with and without 3-vessel CAD were compared.
  
  
  RESULTS
  Among patients with severe 3-vessel CAD, MFR was globally reduced (<2) in 88% (22/25). On the adjusted logistic Cox model, MFR was an independent predictor of 3-vessel CAD [.5 unit decrease, HR: 2.1, 95% CI (1.2-3.8); P = .015]. The incremental value of (82)Rb MFR over the SSS was also shown by comparing the adjusted SSS models with and without (82)Rb MFR (P = .005).
  
  
  CONCLUSIONS
  (82)Rb MFR is an independent predictor of 3-vessel CAD and provided added value to relative MPI. Clinical integration of this approach should be considered to enhance detection and risk assessment of patients with known or suspected CAD.
authors.affiliation: Division of Cardiology, National Cardiac PET Centre, University of Ottawa Heart Institute, Ottawa, ON, Canada. mcziadi@hotmail.com
authors.forename: Maria C
authors.initials: MC
authors.lastname: Ziadi
authors.forename: Robert A
authors.initials: RA
authors.lastname: Dekemp
authors.forename: Kathryn
authors.initials: K
authors.lastname: Williams
authors.forename: Ann
authors.initials: A
authors.lastname: Guo
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Renaud
authors.forename: Benjamin J W
authors.initials: BJ
authors.lastname: Chow
authors.forename: Ran
authors.initials: R
authors.lastname: Klein
authors.forename: Terrence D
authors.initials: TD
authors.lastname: Ruddy
authors.forename: May
authors.initials: M
authors.lastname: Aung
authors.forename: Linda
authors.initials: L
authors.lastname: Garrard
authors.forename: Rob S B
authors.initials: RS
authors.lastname: Beanlands
mesh_terms: D000368:Aged; D002309:Cardiology / Q000379:methods; D015331:Cohort Studies; D017023:Coronary Angiography / Q000379:methods; D001026:Coronary Artery Bypass / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D012414:Rubidium Radioisotopes; D013997:Time Factors
chemical_list: D012414:Rubidium Radioisotopes