title: Addition of copeptin improves diagnostic performance of point-of-care testing (POCT) for cardiac troponin T in early rule-out of myocardial infarction - A pilot study.
abstract: BACKGROUND
  Point of care testing (POCT) assays for cardiac troponin (cTn) are hampered by lower analytical sensitivity and thus suboptimal rule-out of myocardial infarction (MI). We investigated, whether additional measurement of copeptin using an ultrasensitive assay improves diagnostic performance of POCT for cTn T compared to a high sensitivity troponin T (hsTnT) assay.
  
  
  METHODS
  131 patients with suspected acute coronary syndrome were prospectively enrolled in our center 08/2010 to 11/2011. In blood samples obtained at presentation, ultrasensitive copeptin (Kryptor, BRAHMS) and two commercially available POCT assays, AQT90 Flex Radiometer (Radiometer) and Cobas h232 POC-System (Cobas), were tested. HsTnT (Cobas E411, Roche) at baseline and after 3 and 6h in the central laboratory served as reference.
  
  
  RESULTS
  Copeptin improved rule-out of non-STEMI combined with all tested troponin assays. Addition of copeptin increased sensitivity of Cobas from 67.9% (95% CI: 0.506; 0.852) to 89.3% (95% CI: 0.778; 1.007) and Radiometer from 71.4% (95% CI: 0.547; 0.882) to 85.7% (95% CI: 0.728; 0.987), achieving the sensitivity of hsTnT alone at admission of 85.7% (95% CI: 0.728; 0.987). The area under the curve (AUC) of Radiometer (0.822) was numerically but insignificantly (p=0.17) higher than AUC of Cobas (0.725). Addition of copeptin increased AUC of Radiometer to 0.826 (p=0.96) and AUC of Cobas to 0.814 (p=0.20).
  
  
  CONCLUSIONS
  Additional use of ultrasensitive copeptin improves diagnostic performance of conventional sensitive POCT assays overcoming lower sensitivities at the cost of a drop of clinical specificity. When hsTn is temporarily unavailable, copeptin and POCT for cTn may allow initial evaluation at a comparable performance as hsTnT at admission.
authors.affiliation: Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Mehrshad
authors.initials: M
authors.lastname: Vafaie
authors.affiliation: Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Biener
authors.affiliation: Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Mueller
authors.affiliation: Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Haitham
authors.initials: H
authors.lastname: Abu Sharar
authors.affiliation: Thermo Scientific Biomarkers, Thermo Fisher Scientific, Henningsdorf, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Hartmann
authors.affiliation: Thermo Scientific Biomarkers, Thermo Fisher Scientific, Henningsdorf, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Hertel
authors.affiliation: Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Katus
authors.affiliation: Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, Heidelberg, Germany. Electronic address: evangelos_giannitsis@med.uni-heidelberg.de.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Giannitsis
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000175:diagnosis; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002637:Chest Pain / Q000097:blood / Q000175:diagnosis; D003937:Diagnosis, Differential; D004636:Emergency Service, Hospital; D005260:Female; D006020:Glycopeptides / Q000097:blood*; D017408:Guidelines as Topic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis; D010865:Pilot Projects; D000067716:Point-of-Care Testing; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D006020:Glycopeptides; D020107:Troponin T; C048197:copeptins
keywords: Copeptin; High sensitivity troponin T; Point of care testing; Sensitivity and specificity