title: Evaluation of first-draw whole blood, point-of-care cardiac markers in the context of the universal definition of myocardial infarction: a comparison of a multimarker panel to troponin alone and to testing in the central laboratory.
abstract: BACKGROUND
  Previous studies evaluating point-of-care testing (POCT) for cardiac biomarkers did not use current recommendations for troponin cutoff values or recognize the recent universal definition of acute myocardial infarction. Traditionally, achieving optimal sensitivity for the detection of myocardial injury on initial presentation required combining cardiac troponin and/or creatine kinase isoenzyme MB with an early marker, usually myoglobin. In recent years, the performance of central laboratory combining cardiac troponin assays has improved significantly, potentially obviating the need for a multimarker panel to achieve optimum sensitivity.
  
  
  OBJECTIVE
  To compare 2 commonly used POCT strategies to a fourth generation, central laboratory cardiac troponin T assay on first-draw specimens from patients being evaluated for acute myocardial infarction in the emergency department. The 2 strategies included a traditional POCT multimarker panel and a newer POCT method using cardiac troponin I alone.
  
  
  METHODS
  Blood specimens from 204 patients presenting to the emergency department with signs and/or symptoms of myocardial ischemia were measured on the 2 POCT systems and by a central laboratory method. The diagnosis for each patient was determined by retrospective chart review.
  
  
  RESULTS
  The cardiac troponin T assasy alone was more sensitive for acute myocardial infarction than the multimarker POCT panel with equal or better specificity. When compared with a POCT troponin I, the cardiac troponin T was also more sensitive, but this difference was not significant. The POCT troponin I alone also had the same sensitivity as the multimarker panel.
  
  
  CONCLUSIONS
  Testing for combining cardiac troponin alone using newer, commercially available, central laboratory or POCT assays performed with equal or greater sensitivity to acute myocardial infarction as the older, traditional, multimarker panel. In the near future, high-sensitivity, central laboratory troponins will be available for routine clinical use. As a result, the quality gap between central laboratories and older POCT methods will continue to widen, unless the performance of the POCT methods is improved.
authors.affiliation: Departments of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Lee-Lewandrowski
authors.forename: James L
authors.initials: JL
authors.lastname: Januzzi
authors.forename: Ricky
authors.initials: R
authors.lastname: Grisson
authors.forename: Asim A
authors.initials: AA
authors.lastname: Mohammed
authors.forename: Grant
authors.initials: G
authors.lastname: Lewandrowski
authors.forename: Kent
authors.initials: K
authors.lastname: Lewandrowski
mesh_terms: D015415:Biomarkers / Q000097:blood; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D007755:Laboratories, Hospital; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D013997:Time Factors; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T