title: Effectiveness of practices for improving the diagnostic accuracy of Non ST Elevation Myocardial Infarction in the Emergency Department: A Laboratory Medicine Best Practices™ systematic review.
abstract: OBJECTIVE
  This article is a systematic review of the effectiveness of four practices (assay selection, decision point cardiac troponin (cTn) threshold selection, serial testing, and point of care testing) for improving the diagnostic accuracy Non-ST-Segment Elevation Myocardial Infarction (NSTEMI) in the Emergency Department.
  
  
  METHODS
  The CDC-funded Laboratory Medicine Best Practices (LMBP) Initiative systematic review method for quality improvement practices was used.
  
  
  RESULTS
  The current ACC/AHA guidelines recommend using cardiac troponin assays with a 99th percentile upper reference limit (URL) diagnostic threshold to diagnose NSTEMI. The evidence in this systematic review indicates that contemporary sensitive cTn assays meet the assay profile requirements (sensitivity, specificity, PPV, and NPV) to more accurately diagnose NSTEMI than alternate tests. Additional biomarkers did not increase diagnostic effectiveness of cTn assays. Sensitivity, specificity, and NPV were consistently high and low PPV improved with serial sampling. Evidence for use of point of care cTn testing was insufficient to make recommendation, though some evidence suggests that use may result in reduction to patient length of stay and costs.
  
  
  CONCLUSIONS
  Based on the review of and the LMBP(TM) A-6 Method criteria, we recommend the use of cardiac troponin assays without additional biomarkers using the 99th percentile URL as the clinical diagnostic threshold for the diagnosis of NSTEMI. We recommend serial sampling with one sample at presentation and at least one additional second sample taken at least 6h later to identify a rise or fall in the troponin level. No recommendation is made either for or against the use of point of care tests.
  
  
  CONCLUSIONS
  The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention/the Agency for Toxic Substances and Disease Registry (CDC/ATSDR).
authors: Battelle Memorial Institute, USA. Electronic address: layfieldc@battelle.org.
authors: Christopher
authors: C
authors: Layfield
authors: Battelle Memorial Institute, USA.
authors: John
authors: J
authors: Rose
authors: Battelle Memorial Institute, USA.
authors: Aaron
authors: A
authors: Alford
authors: Geisinger Center for Health Research, USA.
authors: Susan R
authors: SR
authors: Snyder
authors: Hennepin County Medical Center, USA; University of Minnesota Medical School, USA.
authors: Fred S
authors: FS
authors: Apple
authors: Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA.
authors: Farah M
authors: FM
authors: Chowdhury
authors: Virginia Commonwealth University Medical Center, USA.
authors: Michael C
authors: MC
authors: Kontos
authors: Duke University Medical Center, USA.
authors: L Kristin
authors: LK
authors: Newby
authors: Vanderbilt University Medical Center, USA.
authors: Alan B
authors: AB
authors: Storrow
authors: Brigham and Women's Hospital, USA; Harvard Medical School, USA.
authors: Milenko
authors: M
authors: Tanasijevic
authors: Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA.
authors: Elizabeth
authors: E
authors: Leibach
authors: American Anthropological Association, USA.
authors: Edward B
authors: EB
authors: Liebow
authors: University of Maryland School of Medicine, USA.
authors: Robert H
authors: RH
authors: Christenson
mesh_terms: D015415:Biomarkers / Q000097:blood; D004636:Emergency Service, Hospital / Q000592:standards*; D006801:Humans; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis*; D017410:Practice Guidelines as Topic / Q000592:standards; D014336:Troponin / Q000097:blood; D019210:Troponin I / Q000097:blood; D020107:Troponin T / Q000097:blood
chemical_list: D015415:Biomarkers; D014336:Troponin; D019210:Troponin I; D020107:Troponin T
keywords: Acute coronary syndrome; Cardiac troponin; Myocardial infarction; Non-ST-segment elevation