title: Predictive significance of detectable cardiac troponin I measured with a contemporary-sensitive assay in a real life experience.
abstract: BACKGROUND
  Cardiac troponin (cTn) testing has reduced the likelihood of erroneous discharge of patients with acute coronary syndrome (ACS) from the emergency department (ED), but doubts remain about optimal clinical use. This study was planned for evaluating the predictive significance of cTn values between the limit of detection of the method and the 99th percentile in ED patients evaluated for suspected ACS.
  
  
  METHODS
  In this retrospective study all hospital records of patients admitted over a 6-month period to the ED and with at least one cTnI value comprised between the limit of detection (0.01 ng/mL) and the 99th percentile of the assay (0.05 ng/mL) were analyzed.
  
  
  RESULTS
  A total of 4,749 patients with cTnI value between 0.01-0.05 ng/mL were identified among 57,879 ED visits throughout the study period. Overall, 2,189 patients (46.1%) were discharged from the ED, 2,529 (53.25%) were admitted to the hospital and 31 (0.65%) died during ED stay. A total number of 289 patients out of 2,189 who were discharged (i.e., 13.2%) had additional ED visits within 30 days. Among these, 6 were diagnosed with ACS, representing 0.27% of patients discharged [negative predictive value (NPV) 0.997; 95% CI, 0.994-0.999] and 2.1% of those with second admission (NPV 0.979; 95% CI, 0.955-0.992). Only one of the 2,529 patients admitted to the hospital (i.e., 0.04%) developed an ACS during hospital stay.
  
  
  CONCLUSIONS
  The results of our retrospective study suggest that the suitability of using a contemporary-sensitive cTnI immunoassay assay in the context of an appropriate protocol represents a safe and effective strategy for ruling in and ruling out ACS in patients presenting to the ED.
authors: Emergency Department, University Hospital of Parma, Parma, Italy ;
authors: Laura
authors: L
authors: Bonfanti
authors: Section of Clinical Biochemistry, University of Verona, Verona, Italy ;
authors: Giuseppe
authors: G
authors: Lippi
authors: Postgraduate Emergency Medicine School, University of Parma, Parma, Italy ;
authors: Irene
authors: I
authors: Ciullo
authors: Postgraduate Emergency Medicine School, University of Parma, Parma, Italy ;
authors: Tiziana
authors: T
authors: Meschi
authors: Postgraduate Emergency Medicine School, University of Parma, Parma, Italy ;
authors: Andrea
authors: A
authors: Ticinesi
authors: Laboratory of Clinical Chemistry and Hematology, University Hospital of Parma, Parma, Italy ;
authors: Rosalia
authors: R
authors: Aloe
authors: Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Francesco
authors: F
authors: Di Spigno
authors: Emergency Department, University Hospital of Parma, Parma, Italy ;
authors: Gianfranco
authors: G
authors: Cervellin
keywords: Acute coronary syndrome (ACS); contemporary sensitive; diagnosis; myocardial infarction; prognosis; troponin