title: The etiology and prognostic significance of cardiac troponin I elevation in unselected emergency department patients.
abstract: BACKGROUND
  Cardiac troponin elevations are associated not only with acute coronary syndromes (ACS) but also with multiple other cardiac and non-cardiac conditions.
  
  
  OBJECTIVE
  To investigate the etiology and clinical significance of cardiac troponin I elevations in an unselected Emergency Department (ED) patient cohort.
  
  
  METHODS
  The study population consisted of 991 consecutive troponin-positive patients admitted to the ED of a university hospital with ACS as the presumptive diagnosis. Cardiac troponin I was measured on admission and a follow-up sample was obtained at 6-12 h. Clinical diagnosis was ascertained retrospectively using all the available information including electrocardiogram, clinical data, laboratory tests, and available coronary angiograms.
  
  
  RESULTS
  At admission, 805 (81.2%) patients were already troponin positive; of these, the troponin elevation was related to myocardial infarction (MI) in 654 (81.2%) patients. Finally, 83.0% of the troponin elevations were due to MI, 7.9% were related to other cardiac causes, and 9.1% to non-cardiac diseases. The leading non-cardiac causes were pulmonary embolism, renal failure, pneumonia, and sepsis. Non-cardiac patients with elevated troponin I at admission showed significantly higher in-hospital mortality (26.7% vs. 13.4%, p = 0.002) compared to cardiac patients.
  
  
  CONCLUSIONS
  Elevated troponin levels for reasons other than MI are common in the ED and are a marker of poor in-hospital prognosis.
authors.affiliation: Department of Internal Medicine, Kanta-Hame Central Hospital, Hameenlinna, Finland.
authors.forename: Tuomo J
authors.initials: TJ
authors.lastname: Ilva
authors.forename: Markku J
authors.initials: MJ
authors.lastname: Eskola
authors.forename: Kjell C
authors.initials: KC
authors.lastname: Nikus
authors.forename: Liisa-Maria
authors.initials: LM
authors.lastname: Voipio-Pulkki
authors.forename: Juha
authors.initials: J
authors.lastname: Lund
authors.forename: Kari
authors.initials: K
authors.lastname: Pulkki
authors.forename: Harri
authors.initials: H
authors.lastname: Mustonen
authors.forename: Kari O
authors.initials: KO
authors.lastname: Niemelä
authors.forename: Pekka J
authors.initials: PJ
authors.lastname: Karhunen
authors.forename: Pekka
authors.initials: P
authors.lastname: Porela
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D004630:Emergencies; D005260:Female; D005387:Finland / Q000453:epidemiology; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis; D011379:Prognosis; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I