title: Quantitative plaque features from coronary computed tomography angiography to identify regional ischemia by myocardial perfusion imaging.
abstract: OBJECTIVE
  We aimed to investigate whether quantitative plaque features measured from coronary CT angiography (CCTA) predict ischemia by myocardial perfusion SPECT imaging (MPI).
  
  
  RESULTS
  Hundred and eighty-four consecutive patients (63% males) with suspected-coronary artery disease, undergoing hybrid CCTA, and attenuation corrected solid state 99mTc stress/rest MPI and single vessel ischemia were considered. Quantitative analysis of CCTA derived non-calcified plaque (NCP), low-density NCP [< 30 Hounsfield Units (HU)] (LDNCP), calcified and total plaque burdens (%, normalized to vessel volume), maximum diameter stenosis and contrast density difference (CD, maximum difference in HU/lumen area within lesion). Normal thresholds for plaque features were defined as 95th percentile thresholds, from 40% of vessels with non-ischemic MPI regions. These vessels were excluded from further analysis. Regional ischemia (≥ 2%) was quantified from MPI. All plaque features were higher in arteries corresponding to ischemia (P < 0.003 for all). In multi-variable analysis, abnormal NCP burden [odds ratio (OR) 2.6], LDNCP burden (OR 3.9), and CD (OR 2.7) were significantly associated with ischemia, whereas stenosis ≥ 50% was not (P = 0.14). In a subset of vessels with ≥ 50% stenosis, LDNCP burden (OR 4.3, P = 0.008) and CD (OR 3.7, P = 0.029) were associated with ischemia. In subsets of vessels with stenosis 30-69% and ≥ 70%, abnormal LDNCP burden (OR 6.4, P = 0.006) and CD (OR 7.3, P = 0.02) were associated with ischemia.
  
  
  CONCLUSIONS
  Quantitative plaque features obtained from CCTA, LDNCP, and CD, are associated with ischemia by MPI independent of stenosis. LDNCP burden and CD are associated with ischemia in stenosis 30-69% and ≥ 70%, respectively.
authors.affiliation: Departments of Imaging (Division of Nuclear Medicine) and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Mariana
authors.initials: M
authors.lastname: Diaz-Zamudio
authors.affiliation: Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Tobias A
authors.initials: TA
authors.lastname: Fuchs
authors.affiliation: Departments of Imaging (Division of Nuclear Medicine) and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Piotr
authors.initials: P
authors.lastname: Slomka
authors.affiliation: Departments of Imaging (Division of Nuclear Medicine) and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Otaki
authors.affiliation: Departments of Imaging (Division of Nuclear Medicine) and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Reza
authors.initials: R
authors.lastname: Arsanjani
authors.affiliation: Departments of Imaging (Division of Nuclear Medicine) and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Heidi
authors.initials: H
authors.lastname: Gransar
authors.affiliation: Departments of Imaging (Division of Nuclear Medicine) and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Guido
authors.initials: G
authors.lastname: Germano
authors.affiliation: Departments of Imaging (Division of Nuclear Medicine) and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Berman
authors.affiliation: Departments of Imaging (Division of Nuclear Medicine) and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Kaufmann
authors.affiliation: Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Damini
authors.initials: D
authors.lastname: Dey
mesh_terms: D000368:Aged; D015331:Cohort Studies; D000072226:Computed Tomography Angiography / Q000379:methods*; D016001:Confidence Intervals; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology; D055414:Myocardial Perfusion Imaging / Q000379:methods; D016017:Odds Ratio; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012720:Severity of Illness Index
keywords: CCTA ; contrast density difference; coronary plaque ; ischemia ; low density non-calcified plaque 