title: Use of the Centaur TnI-Ultra assay for detection of myocardial infarction and adverse events in patients presenting with symptoms suggestive of acute coronary syndrome.
abstract: BACKGROUND
  We determined the diagnostic accuracy of the Advia Centaur TnI-Ultra assay for detecting myocardial infarction (MI) and assessing risk of adverse events in patients presenting with ischemic symptoms suggestive of acute coronary syndrome.
  
  
  METHODS
  We measured cardiac troponin I (cTnI) on admission and 6-24 h after admission (follow-up) in plasma specimens from 371 consecutive patients. The end point was the first of cardiac event or death within 60 days. We estimated survival curves using the Kaplan-Meier method and compared groups with the log rank statistic.
  
  
  RESULTS
  MI was established in 49 patients (13%). Clinical sensitivities and specificities for MI based on the 99th percentile (0.04 microg/L) were 74% and 84%, respectively, on admission and 94% and 81% at follow-up. ROC curves showed significantly higher accuracy for MI in the follow-up specimen compared with admission (P = 0.001). Overall there were 2 cardiac deaths, 1 noncardiac death, 49 MIs, 7 coronary artery bypass grafts, and 36 percutaneous coronary interventions in 59 patients during follow-up. The event rate in those with cTnI <0.006 microg/L was significantly lower than in groups with cTnI 0.006-0.04 microg/L, >0.04-0.10 microg/L, or >0.10 microg/L (2.8% vs 11.1%, 24.1%, 55.1%, respectively; P <0.0001). Relative risks for the increasing cTnI cutoff groups were 3.9 (95% CI 1.2-13), 8.9 (2.4-34), and 25 (7.3-82) after adjustment for age, diabetes, history of hypertension, previous MI, and estimated glomerular filtration rate.
  
  
  CONCLUSIONS
  The TnI-Ultra assay is a sensitive, early diagnostic biomarker for MI and an independent predictor of adverse events at any measurable cTnI in patients with symptoms of acute coronary syndrome.
authors.affiliation: Department of Laboratory Medicine, Hennepin County Medical Center, University of Minnesota School of Medicine, Minneapolis, MN 55415, USA. apple004@umn.edu
authors.forename: Fred S
authors.initials: FS
authors.lastname: Apple
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Smith
authors.forename: Lesly A
authors.initials: LA
authors.lastname: Pearce
authors.forename: Ranka
authors.initials: R
authors.lastname: Ler
authors.forename: Maryann M
authors.initials: MM
authors.lastname: Murakami
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000401:mortality; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012372:ROC Curve; D015996:Survival Rate; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I