title: Performance of the Advia Centaur second-generation troponin assay TnI-Ultra compared with the first-generation cTnI assay.
abstract: BACKGROUND
  A cardiac troponin concentration above the 99th percentile limit of a reference population is a sensitive marker of myocardial necrosis. Current guidelines require troponin assays to have a total imprecision of < or =10% at the 99th percentile limit. In this study, the Advia Centaur second-generation TnI-Ultra assay was validated and compared with its predecessor the cardiac troponin I (cTnI) assay, with a focus on the current guidelines for diagnosis of acute myocardial damage.
  
  
  METHODS
  An imprecision profile of the TnI-Ultra assay was evaluated by analysing different pools over 20 days. The imprecision of the cTnI assay was used as comparison. The reference range was established based on TnI-Ultra analysis in 221 individuals.
  
  
  RESULTS
  The cTnI concentration that could be determined with a total imprecision of 10% was 0.05 microg/L for the TnI-Ultra assay and 0.3 microg/L for the cTnI assay. The 99th percentile limit in the distribution of a reference population was 0.06 microg/L as determined with the TnI-Ultra assay.
  
  
  CONCLUSIONS
  The TnI-Ultra assay provides significantly improved sensitivity when compared with the cTnI assay and a total imprecision of < or =10% is obtained at the 99th percentile limit of value distribution of a reference population. Using the TnI-Ultra assay, slightly increased cTnI concentration can be detected reliably following the current guidelines.
authors.affiliation: Clinical Laboratory, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: Daan
authors.initials: D
authors.lastname: van de Kerkhof
authors.forename: Berry
authors.initials: B
authors.lastname: Peters
authors.forename: Volkher
authors.initials: V
authors.lastname: Scharnhorst
mesh_terms: D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis*; D012016:Reference Values; D012680:Sensitivity and Specificity; D019209:Troponin C / Q000097:blood; D019210:Troponin I / Q000097:blood*; D020107:Troponin T / Q000097:blood
chemical_list: D019209:Troponin C; D019210:Troponin I; D020107:Troponin T