title: High-sensitivity troponin T concentrations in acute chest pain patients evaluated with cardiac computed tomography.
abstract: BACKGROUND
  For evaluation of patients with chest pain and suspected acute coronary syndrome (ACS), consensus guidelines recommend use of a cardiac troponin cut point that corresponds to the 99 th percentile of a healthy population. Most conventional troponin methods lack sufficient precision at this low level.
  
  
  RESULTS
  In a cross-sectional study, 377 patients (mean age 53.7 years, 64.2% male) with chest pain and low to intermediate likelihood for ACS were enrolled in the emergency department. Blood was tested with a precommercial high-sensitivity troponin T assay (hsTnT) and compared with a conventional cardiac troponin T method. Patients underwent a 64-slice coronary computed tomography coronary angiogram at the time of phlebotomy, on average 4 hours from initial presentation. Among patients with acute chest pain, 37 (9.8%) had an ACS. Using the 99th percentile cut point for a healthy population (13 pg/mL), hsTnT had 62% sensitivity, 89% specificity, 38% positive predictive value, and 96% negative predictive value for ACS. Compared with the cardiac troponin T method, hsTnT detected 27% more ACS cases (P=.001), and an hsTnT above the 99 th percentile strongly predicted ACS (odds ratio 9.0, 95% confidence interval 3.9 to 20.9, P<0.001). Independent of ACS diagnosis, computed tomography angiography demonstrated that concentrations of hsTnT were determined by numerous factors, including the presence and severity of coronary artery disease, left ventricular mass, left ventricular ejection fraction, and regional left ventricular dysfunction.
  
  
  CONCLUSIONS
  Among low- to intermediate-risk patients with chest pain, hsTnT provides good sensitivity and specificity for ACS. Elevation of hsTnT identifies patients with myocardial injury and significant structural heart disease, irrespective of the diagnosis of ACS.
authors.affiliation: Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: James L
authors.initials: JL
authors.lastname: Januzzi
authors.forename: Fabian
authors.initials: F
authors.lastname: Bamberg
authors.forename: Hang
authors.initials: H
authors.lastname: Lee
authors.forename: Quynh A
authors.initials: QA
authors.lastname: Truong
authors.forename: John H
authors.initials: JH
authors.lastname: Nichols
authors.forename: Mahir
authors.initials: M
authors.lastname: Karakas
authors.forename: Asim A
authors.initials: AA
authors.lastname: Mohammed
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Schlett
authors.forename: John T
authors.initials: JT
authors.lastname: Nagurney
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Koenig
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D002637:Chest Pain / Q000097:blood* / Q000000981:diagnostic imaging; D017023:Coronary Angiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D020107:Troponin T / Q000097:blood*
chemical_list: D020107:Troponin T