title: A novel diagnostic protocol to identify patients suitable for discharge after a single high-sensitivity troponin.
abstract: OBJECTIVE
  To establish whether a novel accelerated diagnostic protocol (ADP) for suspected acute coronary syndrome (ACS) could successfully identify low-risk patients suitable for discharge after a single high-sensitivity troponin T (hs-cTnT) taken at presentation to the emergency department. We also compared the diagnostic accuracy of this ADP with strategies using initial undetectable hs-cTnT.
  
  
  METHODS
  This prospective observational study evaluated the ability of the Triage Rule-out Using high-Sensitivity Troponin (TRUST) ADP to identify low-risk patients with suspected ACS. The ADP incorporated a single presentation hs-cTnT of <14 ng/L, a non-ischaemic ECG and a modified Goldman risk score. Diagnostic performance of the ADP was compared with the detection limit cut-offs of hs-cTnT (<5 ng/L and <3 ng/L). The primary end point was fatal/non-fatal acute myocardial infarction (AMI) within 30 days.
  
  
  RESULTS
  960 participants were recruited, mean age 58.0 years, 80 (8.3%) had an AMI. The TRUST ADP classified 382 (39.8%) as low-risk with a sensitivity for identifying AMI of 98.8% (95% CI 92.5% to 99.9%). hs-cTnT detection limits (<5 ng/L and <3 ng/L) had a sensitivity of 100% (94.3 to 100) and 100% (94.4 to 100), respectively. The TRUST ADP identified more patients suitable for early discharge at 39.8% vs 29.3% (<5 ng/L) and 7.9% (<3 ng/L) (p<0.001) with a lower false-positive rate for AMI detection; specificity 43.3% (95% CI 42.7% to 43.4%) vs 32.0% (95% CI 31.5% to 32.0%) and 8.6% (95% CI 8.1% to 8.6%), respectively.
  
  
  CONCLUSIONS
  The TRUST ADP, which incorporates structured risk-assessment and a single presentation hs-cTnT blood draw, has potential to allow early discharge in 40% of patients with suspected ACS and has greater clinical utility than undetectable hs-cTnT strategies.
  
  
  BACKGROUND
  ISRCTN No. 21109279.
authors.affiliation: Bournemouth University, Centre of Postgraduate Medical Research & Education, Faculty of Health and Social Sciences, UK Poole Hospital NHS Foundation Trust, Dorset, UK.
authors.forename: Edward W
authors.initials: EW
authors.lastname: Carlton
authors.affiliation: Emergency Department, Royal Brisbane and Women's Hospital, Queensland, Australia.
authors.forename: Louise
authors.initials: L
authors.lastname: Cullen
authors.affiliation: Emergency Department, Christchurch Hospital, New Zealand.
authors.forename: Martin
authors.initials: M
authors.lastname: Than
authors.affiliation: Department of Cardiology, John Radcliffe Hospital, Oxford, UK.
authors.forename: James
authors.initials: J
authors.lastname: Gamble
authors.affiliation: Bournemouth University, Centre of Postgraduate Medical Research & Education, Faculty of Health and Social Sciences, UK.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Khattab
authors.affiliation: Sunshine Coast Hospital and Health Services, University of the Sunshine Coast, Queensland, Australia.
authors.forename: Kim
authors.initials: K
authors.lastname: Greaves
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology; D001315:Australia; D015415:Biomarkers / Q000097:blood; D002985:Clinical Protocols / Q000592:standards*; D003937:Diagnosis, Differential; D061827:Dimensional Measurement Accuracy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge / Q000592:standards*; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D018570:Risk Assessment / Q000379:methods; D012720:Severity of Illness Index; D013997:Time Factors; D014336:Troponin / Q000097:blood*
chemical_list: D015415:Biomarkers; D014336:Troponin