title: Sensitive troponin assays in patients with suspected acute coronary syndrome: Results from the multicenter rule out myocardial infarction using computer assisted tomography II trial.
abstract: BACKGROUND
  Sensitive troponin (Tn) assays have been developed for the evaluation of patients with suspected acute coronary syndrome (ACS). We sought to compare the performance of a commercially available sensitive Tn I (sTnI) and precommercial highly sTnI (hsTnI) method to conventional Tn (cTn) assays.
  
  
  METHODS
  Among patients with acute chest pain but normal cTn in the emergency department of 6 centers, sTnI and hsTnI were measured at baseline, 2 and 4 hours after presentation. Diagnostic accuracy of sTnI and hsTnI relative to cTn for diagnosis during index hospitalization as well as their associations with coronary artery disease in patients randomized to coronary computed tomographic angiography (CTA) was assessed.
  
  
  RESULTS
  Overall, 322 patients were enrolled, of whom 161 had a CTA; 28 had ACS (8.7%), including 21 with unstable angina pectoris (UAP). Both sTnI and hsTnI values at baseline and second draw had significantly higher sensitivity for ACS and UAP than cTn and had significantly greater area under the receiver operator characteristic curve than cTn at first and second draws. Compared with cTn, 29% of ACS cases previously categorized as UAP were reclassified to acute myocardial infarction with sTnI or hsTnI. An hsTnI below limit of detection had 100% negative predictive value for ACS or significant coronary artery stenosis in those randomized to CTA.
  
  
  CONCLUSIONS
  In patients with acute chest discomfort, use of sTnI and hsTnI methods led to significant improvement in the early diagnostic accuracy for ACS, reclassifying one-third of UAP to myocardial infarction. Very low values for hsTnI excluded underlying coronary artery disease.
authors.affiliation: Division of Cardiology, Massachusetts General Hospital, Boston, MA. Electronic address: JJanuzzi@partners.org.
authors.forename: James L
authors.initials: JL
authors.lastname: Januzzi
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Boston, MA.
authors.forename: Umesh
authors.initials: U
authors.lastname: Sharma
authors.affiliation: Department of Biostatistics, Massachusetts General Hospital, Boston, MA.
authors.forename: Pearl
authors.initials: P
authors.lastname: Zakroysky
authors.affiliation: Division of Cardiology, Massachusetts General Hospital, Boston, MA.
authors.forename: Quynh A
authors.initials: QA
authors.lastname: Truong
authors.affiliation: Mallinkrodt Institute of Radiology, Washington University, St Louis, MO.
authors.forename: Pamela K
authors.initials: PK
authors.lastname: Woodard
authors.affiliation: Department of Emergency Medicine, Baystate Medical Center, Springfield, MA.
authors.forename: J Hector
authors.initials: JH
authors.lastname: Pope
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hauser
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Boston, MA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mayrhofer
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital.
authors.forename: J Toby
authors.initials: JT
authors.lastname: Nagurney
authors.affiliation: Department of Biostatistics, Massachusetts General Hospital, Boston, MA.
authors.forename: David
authors.initials: D
authors.lastname: Schoenfeld
authors.affiliation: Department of Emergency Medicine, Baylor College of Medicine, Boston, MA.
authors.forename: W Frank
authors.initials: WF
authors.lastname: Peacock
authors.affiliation: Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, Bethesda, MD.
authors.forename: Jerome L
authors.initials: JL
authors.lastname: Fleg
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Boston, MA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Wiviott
authors.affiliation: Department of Emergency Medicine, Indiana University, Indianapolis, IN.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Pang
authors.affiliation: Department of Medicine, Tufts Medical Center, Boston, MA.
authors.forename: James
authors.initials: J
authors.lastname: Udelson
authors.affiliation: Division of Cardiology, Massachusetts General Hospital, Boston, MA; Department of Radiology, Massachusetts General Hospital, Boston, MA.
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000000981:diagnostic imaging*; D015415:Biomarkers / Q000097:blood; D042241:Early Diagnosis; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T
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