title: Analytical evaluation of a high-sensitivity troponin T assay and its clinical assessment in acute coronary syndrome.
abstract: BACKGROUND
  The recently developed, highly sensitive cardiac troponin T (hs-cTnT) immunoassay improves the detection of acute myocardial infarction (AMI). However, this assay requires further analytical and clinical evaluation.
  
  
  METHODS
  Imprecision, linearity, limits of quantification and interferences were evaluated; hs-cTnT was compared with a conventional cardiac troponin I assay (cTnI), performed on an X-pand(®)HM, in a population of patients with suspected AMI. Finally, the 99th percentile cut-off point for a reference population was explored in 213 healthy control subjects.
  
  
  RESULTS
  Imprecision analysis demonstrated coefficients of variation (CVs) below 4%, linearity showed a 0.999 coefficient of correlation, with excellent recovery (99.9%) and a limit of quantification (10%CV) was found at 9.2 ng/L. A negative interference (>20%) with haemolysis was observed when supplemental haemoglobin was above 0.25 g/dL. Patients with suspected AMI more frequently displayed an increased hs-cTnT (83%) than an increased cTnI (55%, P < 0.01). Unstable angina was present in 63% of patients with an increased hs-cTnT associated with no increase in cTnI. The 99th percentile value for our reference population was 16.9 ng/L. In 213 healthy blood donors, hs-cTnT levels were significantly correlated with age (P < 0.0001), and were higher in men than in women (P < 0.0001).
  
  
  CONCLUSIONS
  The analytical performance of hs-cTnT complied with the international guidelines for AMI detection. Determining the degree of haemolysis in a sample is of paramount importance to the interpretation of hs-cTnT results. The 99th percentile value of our reference population was established.
authors.affiliation: Clinical Chemistry Laboratory, Cochin and Hôtel-Dieu Hospitals, Assistance Publique des Hôpitaux de Paris, Paris, France. camille.gobeaux@cch.aphp.fr
authors.forename: Camille
authors.initials: C
authors.lastname: Chenevier-Gobeaux
authors.forename: Christophe
authors.initials: C
authors.lastname: Meune
authors.forename: Marie-Céline
authors.initials: MC
authors.lastname: Blanc
authors.forename: Luc
authors.initials: L
authors.lastname: Cynober
authors.forename: Patrick
authors.initials: P
authors.lastname: Jaffray
authors.forename: Guillaume
authors.initials: G
authors.lastname: Lefevre
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019937:Diagnostic Techniques and Procedures; D005260:Female; D006801:Humans; D007118:Immunoassay; D057230:Limit of Detection; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D020107:Troponin T / Q000097:blood*; D055815:Young Adult
chemical_list: D020107:Troponin T