title: Adverse outcomes following emergency department discharge of patients with possible acute coronary syndrome.
abstract: OBJECTIVE
  To determine the proportion of adverse events in patients discharged after ED assessment for possible acute coronary syndrome.
  
  
  METHODS
  Prospective observational cohort study enrolling consecutive patients presenting with symptoms suggestive of coronary syndrome. Main outcome was the proportion of adverse coronary events (defined a priori) within 30 days.
  
  
  RESULTS
  Of 2627 patients, 1819 (69%) were discharged without a diagnosis of coronary syndrome and 808 (31%) were admitted for further investigation and treatment. Of these, 385 (14.7%) were given a final diagnosis of acute coronary syndrome. On 30 day follow up, 18 of the discharged patients were diagnosed with acute coronary syndrome (0.7%; 95% confidence intervals [CI] 0.4-1.1%), 10 with unstable angina (0.4%; 95% CI 0.2-0.7%) and 8 with non-ST elevation myocardial infarction (0.3%; 95% CI 0.2-0.6%). There were no cases of ST elevation infarction or death. The sensitivity for diagnosis of acute coronary syndromes was 95.5% (95% CI 92.9-97.3%). Average length of stay was 7 h for discharged patients. Forty-six per cent of patients with diabetes and 47% with a past history of coronary disease were discharged. Subsequent outpatient stress testing was performed in 13.6%.
  
  
  CONCLUSIONS
  In a large Australian ED, less than 1% of patients presenting with symptoms suggestive of coronary syndrome were discharged and subsequently had a 30 day adverse event. Reducing this proportion by admitting patients with traditional risk factors would markedly increase hospital workload. Opportunities exist to improve both the safety and efficiency of chest pain assessment in the ED.
authors.affiliation: Division of Emergency Medicine, Hunter New England Health. Locked Bag 1, Hunter Region Mail Centre, NSW 2310, Australia. conradloten@gmail.com
authors.forename: Conrad
authors.initials: C
authors.lastname: Loten
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Isbister
authors.forename: Melissa
authors.initials: M
authors.lastname: Jamcotchian
authors.forename: Carolyn
authors.initials: C
authors.lastname: Hullick
authors.forename: Patrick
authors.initials: P
authors.lastname: MacElduff
authors.forename: John
authors.initials: J
authors.lastname: Attia
authors.forename: John
authors.initials: J
authors.lastname: Marley
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D002637:Chest Pain / Q000628:therapy; D003951:Diagnostic Errors / Q000517:prevention & control / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D019370:Observation; D010351:Patient Discharge; D011446:Prospective Studies; D016896:Treatment Outcome