title: Comparison of diagnostic accuracy of combined assessment using adenosine stress computed tomography perfusion + computed tomography angiography with transluminal attenuation gradient + computed tomography angiography against invasive fractional flow reserve.
abstract: OBJECTIVE
  The goal of this study was to compare the diagnostic accuracy of combined computed tomography perfusion (CTP) + computed tomography angiography (CTA), transluminal attenuation gradient by 320-detector row computed tomography (TAG320) + CTA, and CTP + TAG320 + CTA (multidetector computed tomography-integrated protocol [MDCT-IP]) assessment in predicting significant fractional flow reserve (FFR).
  
  
  BACKGROUND
  CTA has limited specificity for predicting functionally significant stenoses. Novel CT techniques, including adenosine stress CTP and TAG320, may improve the diagnostic accuracy of CTA.
  
  
  METHODS
  CTA, CTP, and TAG320 were assessed using 320-detector row MDCT. Patients who underwent CTA, CTP, and FFR assessment on invasive coronary angiography were included. CTP was assessed using the visual perfusion assessment. TAG320 was defined as the linear regression coefficient between luminal attenuation and axial distance. A TAG320 cutoff value of -15.1 HU/10 mm as previously described was defined as significant. Functionally significant coronary stenosis was defined as FFR ≤0.8.
  
  
  RESULTS
  The cohort included 75 patients (age 64.1 ± 10.8 years, 52 men) and 44 (35%) FFR-significant vessels. In 127 vessels, CTA predicted FFR-significant stenosis with 89% sensitivity and 65% specificity compared with MDCT-IP, which showed 88% sensitivity and 83% specificity. In 97 vessels in which the results of all techniques were available, TAG320 + CTA (area under the curve [AUC] = 0.844) and CTP + CTA (AUC = 0.845) had comparable per-vessel diagnostic accuracy (p = 0.98). The diagnostic accuracy of MDCT-IP (AUC = 0.91) was superior to TAG320 + CTA or CTP + CTA (p = 0.01).
  
  
  CONCLUSIONS
  In vessels without significant calcification or artefact, TAG320 + CTA and CTP + CTA provide comparable diagnostic accuracy for functional assessment of coronary artery stenosis. MDCT-IP may provide the best diagnostic accuracy for functional assessment of coronary artery stenosis.
authors.affiliation: Monash Cardiovascular Research Centre, Department of Medicine, Monash Medical Centre, Monash University and MonashHeart, Monash Health, Clayton, Australia; Discipline of Medicine, University of Adelaide, Adelaide, Australia. Electronic address: drdenniswong@yahoo.com.au.
authors.forename: Dennis T L
authors.initials: DT
authors.lastname: Wong
authors.affiliation: Monash Cardiovascular Research Centre, Department of Medicine, Monash Medical Centre, Monash University and MonashHeart, Monash Health, Clayton, Australia.
authors.forename: Brian S
authors.initials: BS
authors.lastname: Ko
authors.affiliation: Monash Cardiovascular Research Centre, Department of Medicine, Monash Medical Centre, Monash University and MonashHeart, Monash Health, Clayton, Australia.
authors.forename: James D
authors.initials: JD
authors.lastname: Cameron
authors.affiliation: Discipline of Medicine, University of Adelaide, Adelaide, Australia.
authors.forename: Darryl P
authors.initials: DP
authors.lastname: Leong
authors.affiliation: Monash Cardiovascular Research Centre, Department of Medicine, Monash Medical Centre, Monash University and MonashHeart, Monash Health, Clayton, Australia.
authors.forename: Michael C H
authors.initials: MC
authors.lastname: Leung
authors.affiliation: Monash Cardiovascular Research Centre, Department of Medicine, Monash Medical Centre, Monash University and MonashHeart, Monash Health, Clayton, Australia.
authors.forename: Yuvaraj
authors.initials: Y
authors.lastname: Malaiapan
authors.affiliation: Monash Cardiovascular Research Centre, Department of Medicine, Monash Medical Centre, Monash University and MonashHeart, Monash Health, Clayton, Australia.
authors.forename: Nitesh
authors.initials: N
authors.lastname: Nerlekar
authors.affiliation: Department of Diagnostic Imaging, Monash Medical Centre, Southern Health, Melbourne, Australia.
authors.forename: Marcus
authors.initials: M
authors.lastname: Crossett
authors.affiliation: Monash Cardiovascular Research Centre, Department of Medicine, Monash Medical Centre, Monash University and MonashHeart, Monash Health, Clayton, Australia; Department of Diagnostic Imaging, Monash Medical Centre, Southern Health, Melbourne, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Troupis
authors.affiliation: Monash Cardiovascular Research Centre, Department of Medicine, Monash Medical Centre, Monash University and MonashHeart, Monash Health, Clayton, Australia.
authors.forename: Ian T
authors.initials: IT
authors.lastname: Meredith
authors.affiliation: Monash Cardiovascular Research Centre, Department of Medicine, Monash Medical Centre, Monash University and MonashHeart, Monash Health, Clayton, Australia.
authors.forename: Sujith K
authors.initials: SK
authors.lastname: Seneviratne
mesh_terms: D000241:Adenosine; D000368:Aged; D015331:Cohort Studies; D017023:Coronary Angiography / Q000592:standards*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005080:Exercise Test / Q000592:standards*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000592:standards*; D055420:Perfusion Imaging; D012189:Retrospective Studies
chemical_list: D000241:Adenosine
keywords: CTA; FFR; TAG320; adenosine stress CTP