title: Diagnostic and prognostic value of high-sensitivity cardiac troponin T in patients with syncope.
abstract: OBJECTIVE
  We examined the diagnostic and predictive value of high-sensitivity cardiac troponin T (cTnThs) in patients with syncope.
  
  
  METHODS
  We performed an analysis of consecutive patients with syncope presenting to the emergency department. The primary end point was the accuracy to diagnose a cardiac syncope. In addition, the study explored the prognostic relevance of cTnThs in patients with cardiac and noncardiac syncope.
  
  
  RESULTS
  A total of 360 patients were enrolled (median age, 70.5 years; male, 55.8%; 23.9% aged >80 years). Cardiac syncope was present in 22% of patients, reflex syncope was present in 40% of patients, syncope due to orthostatic hypotension was present in 20% of patients, and unexplained syncope was present in 17.5% of patients. A total of 148 patients (41%) had cTnThs levels above the 99% confidence interval (CI) (cutoff point). The diagnostic accuracy for cTnThs levels to determine the diagnosis of cardiac syncope was quantified by the area under the curve (0.77; CI, 0.72-0.83; P < .001). A comparable area under the curve (0.78; CI, 0.73-0.83; P < .001) was obtained for the predictive value of cTnThs levels within 30 days: Patients with increased cTnThs levels had a 52% likelihood for adverse events, patients with cTnThs levels below the cutoff point had a low risk (negative predictive value, 83.5%). Increased cTnThs levels indicate adverse prognosis in patients with noncardiac causes of syncope, but not in patients with cardiac syncope being a risk factor for adverse outcome by itself.
  
  
  CONCLUSIONS
  Patients with syncope presenting to the emergency department have a high proportion of life-threatening conditions. cTnThs levels show a limited diagnostic and predictive accuracy for the identification of patients with syncope at high risk.
authors.affiliation: Department of Emergency and Intensive Care Medicine, Paracelsus Medical University, Nuremberg, Germany. Electronic address: michael.christ@klinikum-nuernberg.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Christ
authors.affiliation: Department of Emergency and Intensive Care Medicine, Paracelsus Medical University, Nuremberg, Germany.
authors.forename: Felicitas
authors.initials: F
authors.lastname: Geier
authors.affiliation: Department of Emergency and Intensive Care Medicine, Paracelsus Medical University, Nuremberg, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Popp
authors.affiliation: Institute for Biomedicine of Aging, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Singler
authors.affiliation: Center of Trauma and Orthopaedic Surgery, Helios Vogtland-Klinikum Plauen, Plauen, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Smolarsky
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, Paracelsus Medical University, Nuremberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bertsch
authors.affiliation: Department of Cardiology, University Hospital Basel, Basel, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Müller
authors.affiliation: Department of Emergency and Intensive Care Medicine, Paracelsus Medical University, Nuremberg, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Greve
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D004636:Emergency Service, Hospital; D005260:Female; D006331:Heart Diseases / Q000097:blood / Q000150:complications / Q000175:diagnosis; D006801:Humans; D007024:Hypotension, Orthostatic / Q000097:blood / Q000150:complications / Q000175:diagnosis; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013575:Syncope / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T
keywords: Cardiac troponin; Emergency service; Healthcare; Hospital; Quality Indicators; Quality of Healthcare; Syncope