title: Aortic distensibility and its relationship to coronary and thoracic atherosclerosis plaque and morphology by MDCT: insights from the ROMICAT Trial.
abstract: BACKGROUND
  Multi-detector cardiac computed tomography (CT) allows for simultaneous assessment of aortic distensibility (AD), coronary atherosclerosis, and thoracic aortic atherosclerosis.
  
  
  OBJECTIVE
  We sought to determine the relationship of AD to the presence and morphological features in coronary and thoracic atherosclerosis.
  
  
  METHODS
  In 293 patients (53 ± 12 years, 63% male), retrospectively-gated MDCT were performed. We measured intraluminal aortic areas across 10 phases of the cardiac cycle (multiphase reformation 10% increments) at pre-defined locations to calculate the ascending, descending, and local AD (at locations of thoracic plaque). AD was calculated as maximum change in area/(minimum area × pulse pressure). Coronary and thoracic plaques were categorized as calcified, mixed, or non-calcified.
  
  
  RESULTS
  Ascending and descending AD were lower in patients with any coronary plaque, calcified or mixed plaque than those without (all p<0.0001) but not with non-calcified coronary plaque (p ≥ 0.46). Per 1mm Hg(-1) 10(-3) increase in ascending and descending AD, there was an 18-29% adjusted risk reduction for having any coronary, calcified plaque, or mixed coronary plaque (ascending AD only) (all p ≤ 0.04). AD was not associated with non-calcified coronary plaque or when age was added to the models (all p>0.39). Local AD was lower at locations of calcified and mixed thoracic plaque when compared to non-calcified thoracic atherosclerosis (p<0.04).
  
  
  CONCLUSIONS
  A stiffer, less distensible aorta is associated with coronary and thoracic atherosclerosis, particularly in the presence of calcified and mixed plaques, suggesting that the mechanism of atherosclerosis in small and large vessels is similar and influenced by advancing age.
authors.affiliation: Cardiac MR PET CT Program, Division of Cardiology and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Siegel
authors.forename: Wai-Ee
authors.initials: WE
authors.lastname: Thai
authors.forename: Tust
authors.initials: T
authors.lastname: Techasith
authors.forename: Gyongyi
authors.initials: G
authors.lastname: Major
authors.forename: Jackie
authors.initials: J
authors.lastname: Szymonifka
authors.forename: Ahmed
authors.initials: A
authors.lastname: Tawakol
authors.forename: John T
authors.initials: JT
authors.lastname: Nagurney
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.forename: Quynh A
authors.initials: QA
authors.lastname: Truong
mesh_terms: D000328:Adult; D000368:Aged; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012189:Retrospective Studies; D016037:Single-Blind Method; D013895:Thoracic Arteries / Q000000981:diagnostic imaging*