title: Common carotid intima media thickness and ankle-brachial pressure index correlate with local but not global atheroma burden: a cross sectional study using whole body magnetic resonance angiography.
abstract: BACKGROUND
  Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA).
  
  
  METHODS
  50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50-70%, 3 = 70-99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated.
  
  
  RESULTS
  The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045), however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β -0.39, p = 0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45), while the correlation between ABPI and atheroma burden persisted (β -0.45 p = 0.005).
  
  
  CONCLUSIONS
  ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral arterial disease. However this is primarily due to a strong correlation with ilio-femoral atheroma burden.
authors.affiliation: Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, University of Dundee, Dundee, United Kingdom; NHS Tayside Clinical Radiology, Ninewells Hospital, Dundee, United Kingdom.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Weir-McCall
authors.affiliation: Vascular & Inflammatory Diseases Research Unit, Medical Research Institute, University of Dundee, Dundee, United Kingdom.
authors.forename: Faisel
authors.initials: F
authors.lastname: Khan
authors.affiliation: Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, University of Dundee, Dundee, United Kingdom.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Lambert
authors.affiliation: University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom.
authors.forename: Carly L
authors.initials: CL
authors.lastname: Adamson
authors.affiliation: University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Gardner
authors.affiliation: NHS Tayside Medical Physics, Ninewells Hospital, Dundee, United Kingdom.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Gandy
authors.affiliation: NHS Tayside Clinical Radiology, Ninewells Hospital, Dundee, United Kingdom.
authors.forename: Prasad Guntur
authors.initials: PG
authors.lastname: Ramkumar
authors.affiliation: Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, University of Dundee, Dundee, United Kingdom.
authors.forename: Jill J F
authors.initials: JJ
authors.lastname: Belch
authors.affiliation: Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, University of Dundee, Dundee, United Kingdom.
authors.forename: Allan D
authors.initials: AD
authors.lastname: Struthers
authors.affiliation: Dundee epidemiological and biostatistics unit, University of Dundee, Dundee, United Kingdom.
authors.forename: Petra
authors.initials: P
authors.lastname: Rauchhaus
authors.affiliation: Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, University of Dundee, Dundee, United Kingdom.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Morris
authors.affiliation: Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, University of Dundee, Dundee, United Kingdom; NHS Tayside Clinical Radiology, Ninewells Hospital, Dundee, United Kingdom.
authors.forename: J Graeme
authors.initials: JG
authors.lastname: Houston
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D015415:Biomarkers; D017536:Carotid Artery, Common / Q000648:ultrastructure*; D059168:Carotid Intima-Media Thickness; D003287:Contrast Media; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009942:Organometallic Compounds; D058729:Peripheral Arterial Disease / Q000473:pathology*; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D016037:Single-Blind Method; D059289:Vascular Stiffness; D051598:Whole Body Imaging / Q000379:methods*
chemical_list: D015415:Biomarkers; D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine