title: A single value of high-sensitive troponin T below the limit of detection is not enough for ruling out non ST elevation myocardial infarction in the emergency department.
abstract: BACKGROUND
  Recent 2015 ESC recommendations for the management of patients with suspected acute myocardial infarction (AMI) support that a single value of high-sensitivity cardiac troponin (HS-cTn) measured at presentation could rule out AMI if below the limit of blank (LoB) or detection (LoD).
  
  
  OBJECTIVE
  We aimed to evaluate whether an undetectable HS-cTnT at presentation safely rules out NSTEMI in unselected patients with chest pain.
  
  
  METHODS
  This is a post hoc analysis of two prospective cohorts with similar design that included patients suspected of AMI at three French university hospitals. Patients were followed-up during one month, before the adjudication of a final diagnosis.
  
  
  RESULTS
  413 patients (mean age 58±17years) were analyzed; 45 (11%) had a final diagnosis of NSTEMI, and 26 (6%) had STEMI. The sensitivity of HS-cTnT value at 3ng/L (LoB) for NSTEMI was 97.8% [95% CI: 86.8-99.9], yielding a negative predictive value (NPV) of 99.3% [95% CI: 95.4-100.0]. Proportion of patients ruled out for NSTEMI was 32% when applying the LoB. The sensitivity of HS-cTnT value at 5ng/L (LoD) was 97.8% [95% CI: 86.8-99.9] yielding a NPV of 99.5% [95% CI: 96.5-100.0]. Proportion of patients ruled out for NSTEMI was 43% when applying the LoD. One patient (delay between onset of chest pain and presentation <3h) had NSTEMI and HS-cTnT <LoB at presentation.
  
  
  CONCLUSIONS
  The NPV of a single measurement of HS-cTnT below the LoD is high in unselected patients, but not enough to rule out safely NSTEMI for very early presenters.
authors.affiliation: Department of Automated Biological Diagnosis, Hôpital Cochin, Hôpitaux Universitaires Paris Centre (HUPC), Assistance Publique des Hôpitaux de Paris (AP-HP), 75014 Paris Cedex, France. Electronic address: camille.gobeaux@cch.aphp.fr.
authors.forename: Camille
authors.initials: C
authors.lastname: Chenevier-Gobeaux
authors.affiliation: Department of Cardiology, Hôpital Avicenne, Hôpitaux Universitaires Paris Seine Saint Denis, Assistance Publique des Hôpitaux de Paris (AP-HP), Bobigny, Université Paris 13, UMR S-942, Paris, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Meune
authors.affiliation: Department of Biochemistry and Hormonology, Hôpital Tenon, Hôpitaux Universitaires est Parisiens (HUEP), Assistance Publique des Hôpitaux de Paris (AP-HP), 4 Rue de la Chine, 75020 Paris, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Lefevre
authors.affiliation: Department of Emergency Medicine, Hôpital Cochin, Hôpitaux Universitaires Paris Centre (HUPC), Assistance Publique des Hôpitaux de Paris (AP-HP), 75014 Paris Cedex, France; Université Paris Descartes, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Doumenc
authors.affiliation: Department of Cardiology, Hôpital Avicenne, Hôpitaux Universitaires Paris Seine Saint Denis, Assistance Publique des Hôpitaux de Paris (AP-HP), Bobigny, Université Paris 13, UMR S-942, Paris, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Sorbets
authors.affiliation: Department of Emergency Medicine, Hôpital Tenon, Hôpitaux Universitaires est Parisiens (HUEP), Assistance Publique des Hôpitaux de Paris (AP-HP), 4 Rue de la Chine, 75020 Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Peschanski
authors.affiliation: Department of Emergency Medicine, Hôpital Tenon, Hôpitaux Universitaires est Parisiens (HUEP), Assistance Publique des Hôpitaux de Paris (AP-HP), 4 Rue de la Chine, 75020 Paris, France; Sorbonne Universités UMPC Université Paris 06, Paris, DHU Fighting Aging and Stress (FAST) Université Pierre et Marie Curie Paris 6, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ray
mesh_terms: D000328:Adult; D000368:Aged; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D000072658:Non-ST Elevated Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D011237:Predictive Value of Tests; D020107:Troponin T / Q000097:blood*
chemical_list: D020107:Troponin T
keywords: Acute coronary syndrome; Acute myocardial infarction; Chest pain; Emergency department; High sensitive troponin