title: Troponin T measurements by high-sensitivity vs conventional assays for risk stratification in acute dyspnea.
abstract: BACKGROUND
  Cardiac troponin T measured by a high-sensitivity assay (hs-cTnT) recently proved to be of prognostic value in several populations. The hs-cTnT assay may also improve risk stratification in acute dyspnea.
  
  
  METHODS
  We prospectively studied the prognostic value of hs-cTnT in 678 consecutive patients presenting to the emergency department with acute dyspnea. On the basis of conventional cardiac troponin T assay (cTnT) and hs-cTnT assay measurements, patients were divided into 3 categories: (1) neither assay increased (cTnT<0.03 μg/L, hs-cTnT<0.016 μg/L), (2) only hs-cTnT increased≥0.016 μg/L (cTnT<0.03 μg/L), and (3) both assays increased (cTnT≥0.03 μg/L, hs-cTnT≥0.016 μg/L). Moreover, the prognostic value of hs-cTnT was investigated if cTnT was not detectable (<0.01).
  
  
  RESULTS
  One hundred seventy-two patients were in the lowest, 282 patients in the middle, and 223 patients in the highest troponin category. Patients in the second and third categories had significantly higher mortality compared to those in the first category (90-day mortality rate 2%, 10%, and 26% in groups 1, 2, and 3, respectively, P<0.001; 1-year mortality rate 9%, 21%, and 39%, P<0.001). Importantly, in patients with undetectable cTnT (n=347, 51%), increased hs-cTnT indicated worse outcome [90-day mortality, odds ratio 4.26 (95% CI 1.19-15.21); 1-year mortality, hazard ratio 2.27 (1.19-4.36), P=0.013], whereas N-terminal pro-brain-type natriuretic peptide (NT-proBNP) was not predictive of short-term outcome.
  
  
  CONCLUSIONS
  hs-cTnT is associated with mortality in patients presenting with acute dyspnea. hs-cTnT concentrations provide additional prognostic information to cTnT and NT-proBNP testing in patients with cTnT concentrations below the detection limit. In particular, the hs-cTnT cutoff of 0.016 μg/L enables identification of low-risk patients.
authors.affiliation: Department of Cardiology, Maastricht University Medical Center, CARIM, Maastricht, the Netherlands. sandra.van.wijk@mumc.nl
authors.forename: Sandra
authors.initials: S
authors.lastname: van Wijk
authors.forename: Leo
authors.initials: L
authors.lastname: Jacobs
authors.forename: Luc W
authors.initials: LW
authors.lastname: Eurlings
authors.forename: Roland
authors.initials: R
authors.lastname: van Kimmenade
authors.forename: Roosmarijn
authors.initials: R
authors.lastname: Lemmers
authors.forename: Pieter
authors.initials: P
authors.lastname: Broos
authors.forename: Otto
authors.initials: O
authors.lastname: Bekers
authors.forename: Martin H
authors.initials: MH
authors.lastname: Prins
authors.forename: Harry J
authors.initials: HJ
authors.lastname: Crijns
authors.forename: Yigal M
authors.initials: YM
authors.lastname: Pinto
authors.forename: Marja P
authors.initials: MP
authors.lastname: van Dieijen-Visser
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Brunner-La Rocca
mesh_terms: D000208:Acute Disease; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000401:mortality; D004417:Dyspnea / Q000175:diagnosis* / Q000401:mortality; D006801:Humans; D011379:Prognosis; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T