title: Risk model for suspected acute coronary syndrome is of limited value in an emergency department.
abstract: BACKGROUND
  Among patients with acute chest pain, acute coronary syndrome (ACS) is seen only in a minority of the patients, which raises the question, whether it is possible to separate a group with a high risk of ACS for admission to a cardiac care unit (CCU) from those with a low risk who would be treated at an emergency department (ED). The aim of this study was to describe a risk stratification model for a Danish context.
  
  
  METHODS
  This was a historic prospective cohort study of patients with suspicion of ACS. The patient was defined as a low-risk patient and admitted to the ED if: 1) electrocardiogram (ECG) was normal, 2) the patient did not have persisting chest pain and 3) there was no history of ischaemic heart disease, heart failure or cardioverter defibrillator. Otherwise, patients were admitted to the CCU. The primary outcome was whether the ACS diagnosis was confirmed or rejected.
  
  
  RESULTS
  We included a total of 488 patients with suspicion of ACS, 50% of whom were low-risk patients. 17% had a verified ACS; 10% of those in the low-risk group and 24% of those in the high-risk group (p = 0.0001). Among the verified ACS cases, 71% went primarily to the CCU. The odds ratio for an ACS if assigned to the high-risk group was 3.0. Allocation to the high-risk group, male gender and age above 60 years was associated with a higher risk of ACS. For patients fulfilling the high-risk definition, sensitivity was 71%, specificity 55%, negative predictive value 90% and positive predictive value 24% for an ACS.
  
  
  CONCLUSIONS
  The model for stratification separated patients into two equal groups, allocated 71% of all ACS directly to the CCU and could not be improved by any of the additional factors examined. Further development of referral strategies for chest pain patients is required.
  
  
  BACKGROUND
  none.
  
  
  BACKGROUND
  not relevant.
authors.affiliation: christian.backer.mogensen@rsyd.dk.
authors.forename: Christian Backer
authors.initials: CB
authors.lastname: Mogensen
authors.forename: Maja
authors.initials: M
authors.lastname: Christiansen
authors.forename: Jess Bjerre
authors.initials: JB
authors.lastname: Jørgensen
authors.forename: Peter Bisgaard
authors.initials: PB
authors.lastname: Staehr
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D002637:Chest Pain / Q000209:etiology*; D004562:Electrocardiography; D004636:Emergency Service, Hospital / Q000458:organization & administration*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*