title: Missed myocardial infarctions in ED patients prospectively categorized as low risk by established risk scores.
abstract: OBJECTIVE
  Few studies have prospectively compared multiple cardiac risk prediction scores. We compared the rate of missed acute myocardial infarction (AMI) in chest pain patients prospectively categorized as low risk by unstructured clinical impression, and by HEART, TIMI, GRACE, and EDACS scores, in combination with two negative contemporary cardiac troponins (cTn) available in the U.S.
  
  
  METHODS
  We enrolled 434 patients with chest pain presenting to one of seven emergency departments (ED). Risk scores were prospectively calculated and included the first two cTn. Low risk was defined for each score as HEART≤3, TIMI≤0, GRACE≤50, and EDACS≤15. AMI incidence was calculated for low risk patients and compared across scores using Χ2tests and C statistics.
  
  
  RESULTS
  The patients' median age was 57, 58% were male, 60% white, and 80 (18%) had AMI. The missed AMI rate in low risk patients for each of the scores when combined with 2 cTn were HEART 3.6%, TIMI 0%, GRACE 6.3%, EDACS 0.9%, and unstructured clinical impression 0%. The C-statistic was greatest for the EDACS score, 0.94 (95% CI, 0.92-0.97).
  
  
  CONCLUSIONS
  Using their recommended cutpoints and non high sensitivity cTn, TIMI and unstructured clinical impression were the only scores with no missed cases of AMI. Using lower cutpoints (GRACE≤48, TIMI=0, EDACS≤11, HEART≤2) missed no case of AMI, but classified less patients as low-risk.
authors.affiliation: Department of Emergency Medicine, Stony Brook University, Stony Brook, NY, United States. Electronic address: adam.singer@stonybrook.edu.
authors.forename: A J
authors.initials: AJ
authors.lastname: Singer
authors.affiliation: Department of Emergency Medicine, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: M P
authors.initials: MP
authors.lastname: Than
authors.affiliation: Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN, United States.
authors.forename: S
authors.initials: S
authors.lastname: Smith
authors.affiliation: Department of Cardiology, Baylor University Medical Center, Dallas, TX, United States.
authors.forename: P
authors.initials: P
authors.lastname: McCullough
authors.affiliation: Department of Emergency Medicine, Vanderbilt University, Nashville, TN, United States.
authors.forename: T W
authors.initials: TW
authors.lastname: Barrett
authors.affiliation: Department of Emergency Medicine, Methodist Hospital, New York, NY, United States.
authors.forename: R
authors.initials: R
authors.lastname: Birkhahn
authors.affiliation: International Heart Institute of Montana, Missoula, MT, United States.
authors.forename: M
authors.initials: M
authors.lastname: Reed
authors.affiliation: Department of Emergency Medicine, Stony Brook University, Stony Brook, NY, United States.
authors.forename: H C
authors.initials: HC
authors.lastname: Thode
authors.affiliation: Alere, San Diego, CA, United States.
authors.forename: W D
authors.initials: WD
authors.lastname: Arnold
authors.affiliation: Department of Medicine, Division of Cardiology, University of California San Diego, La Jolla, CA, United States.
authors.forename: L B
authors.initials: LB
authors.lastname: Daniels
authors.affiliation: Department of Emergency Medicine, University of Maryland, Baltimore, MD, United States.
authors.forename: C
authors.initials: C
authors.lastname: de Filippi
authors.affiliation: Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC, United States.
authors.forename: G
authors.initials: G
authors.lastname: Headden
authors.affiliation: Department of Emergency Medicine, Baylor College of Medicine, Houston, TX, United States.
authors.forename: W F
authors.initials: WF
authors.lastname: Peacock
mesh_terms: D002637:Chest Pain / Q000097:blood / Q000175:diagnosis*; D003661:Decision Support Techniques; D004562:Electrocardiography / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D014336:Troponin / Q000097:blood*
chemical_list: D014336:Troponin