title: Structural epicardial disease and microvascular function are determinants of an abnormal longitudinal myocardial blood flow difference in cardiovascular risk individuals as determined with PET/CT.
abstract: BACKGROUND
  The aim of this study was to determine whether epicardial structural disease may affect the manifestation of a longitudinal decrease in myocardial blood flow (MBF) or MBF difference during hyperemia in cardiovascular risk individuals, and its dependency on the flow increase.
  
  
  RESULTS
  In 54 cardiovascular risk individuals (at risk) and in 26 healthy controls, MBF was measured with (13)N-ammonia and PET/CT in mL/g/min at rest and during dipyridamole stimulation. Computed tomography coronary angiography (CTA) was performed using a 64-slice CT of a PET/CT system. Absolute MBFs during dipyridamole stimulation were mildly lower in the mid-distal than in the mid-LV myocardium in controls (2.20 ± .51 vs 2.29 ± .51, P < .0001), while it was more pronounced in at risk with normal and abnormal CTA (1.56 ± .42 vs 1.91 ± .46 and 1.18 ± .34 vs 1.51 ± .40 mL/g/min, respectively, P < .0001), resulting in a longitudinal MBF difference that was highest in at risk with normal CTA, intermediate in at risk abnormal CTA, and lowest in controls (.35 ± .16 and .22 ± .09 vs .09 ± .04 mL/g/min, respectively, P < .0001). On multivariate analysis, log-CCS and mid-LV hyperemic MBF increase, indicative of microvascular function, were independent predictors of the observed longitudinal MBF difference (P ≤ .004 by ANOVA).
  
  
  CONCLUSIONS
  Epicardial structural disease and microvascular function are important determinants of an abnormal longitudinal MBF difference as determined with PET/CT.
authors.affiliation: Department of Internal Medicine, Cardiovascular Center, Nuclear Cardiology, University Hospital of Geneva, Geneva, Switzerland.
authors.forename: Ines
authors.initials: I
authors.lastname: Valenta
authors.forename: Alessandra
authors.initials: A
authors.lastname: Quercioli
authors.forename: Gabriella
authors.initials: G
authors.lastname: Vincenti
authors.forename: René
authors.initials: R
authors.lastname: Nkoulou
authors.forename: Stephan
authors.initials: S
authors.lastname: Dewarrat
authors.forename: Olivier
authors.initials: O
authors.lastname: Rager
authors.forename: Habib
authors.initials: H
authors.lastname: Zaidi
authors.forename: Yann
authors.initials: Y
authors.lastname: Seimbille
authors.forename: Francois
authors.initials: F
authors.lastname: Mach
authors.forename: Osman
authors.initials: O
authors.lastname: Ratib
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Schindler
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D016022:Case-Control Studies; D003326:Coronary Circulation; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D010496:Pericardium / Q000473:pathology*; D049268:Positron-Emission Tomography / Q000379:methods*; D012306:Risk; D014057:Tomography, X-Ray Computed / Q000379:methods*