title: Quantitative relationship between coronary artery calcium and myocardial blood flow by hybrid rubidium-82 PET/CT imaging in patients with suspected coronary artery disease.
abstract: We assessed the relationship between coronary artery calcium (CAC) score, myocardial blood flow (MBF) and coronary flow reserve (CFR) in patients undergoing hybrid82Rb positron emission tomography (PET)/computed tomography (CT) imaging for suspected CAD. We also evaluated if CAC score is able to predict a reduced CFR independently from conventional coronary risk factors.
  
  
  
  A total of 637 (mean age 58 ± 13 years) consecutive patients were studied. CAC score was measured according to the Agatston method and patients were categorized into 4 groups (0, 0.01-99.9, 100-399.9, and ≥400). Baseline and hyperemic MBF were automatically quantified. CFR was calculated as the ratio of hyperemic to baseline MBF and it was considered reduced when <2.
  
  
  
  Global CAC score showed a significant inverse correlation with hyperemic MBF and CFR (both P < .001), while no correlation between CAC score and baseline MBF was found. At multivariable logistic regression analysis age, diabetes and CAC score were independently associated with reduced CFR (all P < .001). The addition of CAC score to clinical data increased the global chi-square value for predicting reduced CFR from 81.01 to 91.13 (P < .01). Continuous net reclassification improvement, obtained by adding CAC score to clinical data, was 0.36.
  
  
  
  CAC score provides incremental information about coronary vascular function over established CAD risk factors in patients with suspected CAD and it might be helpful for identifying those with a reduced CFR.
authors.affiliation: Department of Advanced Biomedical Sciences, University Federico II, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Assante
authors.affiliation: Department of Advanced Biomedical Sciences, University Federico II, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Emilia
authors.initials: E
authors.lastname: Zampella
authors.affiliation: Nuclear Medicine Center, Central Manchester University Teaching Hospitals, Manchester, UK.
authors.forename: Parthiban
authors.initials: P
authors.lastname: Arumugam
authors.affiliation: Department of Advanced Biomedical Sciences, University Federico II, Via Pansini 5, 80131, Naples, Italy.|Institute of Biostructure and Bioimaging, National Council of Research, Naples, Italy.
authors.forename: Wanda
authors.initials: W
authors.lastname: Acampa
authors.affiliation: Department of Advanced Biomedical Sciences, University Federico II, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Imbriaco
authors.affiliation: Nuclear Medicine Center, Central Manchester University Teaching Hospitals, Manchester, UK.
authors.forename: Deborah
authors.initials: D
authors.lastname: Tout
authors.affiliation: Department of Translational Medical Sciences, University Federico II, Naples, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Petretta
authors.affiliation: Nuclear Medicine Center, Central Manchester University Teaching Hospitals, Manchester, UK.
authors.forename: Christine
authors.initials: C
authors.lastname: Tonge
authors.affiliation: Department of Advanced Biomedical Sciences, University Federico II, Via Pansini 5, 80131, Naples, Italy. cuocolo@unina.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Cuocolo
mesh_terms: D001783:Blood Flow Velocity; D015897:Comorbidity; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology*; D003326:Coronary Circulation; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D015995:Prevalence; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012414:Rubidium Radioisotopes; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D061205:Vascular Calcification
chemical_list: D019275:Radiopharmaceuticals; D012414:Rubidium Radioisotopes
keywords: Coronary artery calcium; PET/CT; coronary artery disease; coronary flow reserve; myocardial blood flow