title: Prevalence and factors associated with false positive suspicion of acute aortic syndrome: experience in a patient population transferred to a specialized aortic treatment center.
abstract: OBJECTIVE
  Acute aortic syndrome (AAS) is a medical emergency that requires prompt diagnosis and treatment at specialized centers. We sought to determine the frequency and etiology of false positive activation of a regional AAS network in a patient population emergently transferred for suspected AAS.
  
  
  METHODS
  We evaluated 150 consecutive patients transferred from community emergency departments directly to our Cardiac Intensive Care Unit (CICU) with a diagnosis of suspected AAS between March, 2010 and August, 2011. A final diagnosis of confirmed acute Type A, acute Type B dissection, and false positive suspicion of dissection was made in 63 (42%), 70 (46.7%) and 17 (11.3%) patients respectively.
  
  
  RESULTS
  Of the 17 false positive transfers, ten (58.8%) were suspected Type A dissection and seven (41.2%) were suspected Type B dissection. The initial hospital diagnosis in 15 (88.2%) patients was made by a computed tomography (CT) scan and 10 (66.6%) of these patients required repeat imaging with an ECG-synchronized CT to definitively rule out AAS. Five (29.4%) patients had prior history of open or endovascular aortic repair. Overall in-hospital mortality was 9.3%.
  
  
  CONCLUSIONS
  The diagnosis of AAS is confirmed in most patients emergently transferred for suspected AAS. False positive activation in this setting is driven primarily by uncertainty secondary to motion-artifact of the ascending aorta and the presence of complex anatomy following prior aortic intervention. Network-wide standardization of imaging strategies, and improved sharing of imaging may further improve triage of this complex patient population.
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Chad E
authors.initials: CE
authors.lastname: Raymond
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Bhuvnesh
authors.initials: B
authors.lastname: Aggarwal
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Schoenhagen
authors.affiliation: Emergency Medicine Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Damon M
authors.initials: DM
authors.lastname: Kralovic
authors.affiliation: Emergency Medicine Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Kristopher
authors.initials: K
authors.lastname: Kormos
authors.affiliation: Emergency Medicine Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: David
authors.initials: D
authors.lastname: Holloway
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Venu
authors.initials: V
authors.lastname: Menon
keywords: Acute aortic syndrome (AAS); aortic dissection; false positive; hospital transfer