title: High sensitivity troponin: Does the 50% delta change alter clinical outcomes in chest pain presentations to the emergency room?
abstract: BACKGROUND
  The National Heart Foundation (NHF) and Cardiac Society of Australia and New Zealand (CSANZ) Acute Coronary Syndrome (ACS) guidelines recommend the use of a high sensitivity troponin assay (hsTrop) in the assessment of patients presenting with ACS. A troponin delta of 50% compared with the previously recommended 20% is advocated by the guidelines to aid in the clinical diagnosis of ACS. We sought to determine the clinical impact of the updated recommendation to use 50% troponin delta for patients presenting with chest pain to the emergency department.
  
  
  METHODS
  We retrospectively collected data for all patients >18 years presenting with chest or abdominal pain with a hsTrop test performed between January-June 2012. Patients with a STEMI, lacked serial hsTrop, were on dialysis or had trauma-related pain were excluded.
  
  
  RESULTS
  Of the 1054 eligible patients, 422 (40%) with serial hsTrop had at least one abnormal troponin (>14 ng/ml). 73 (6.9%) fell within 20-50%. Twenty-seven had clinical or ECG evidence suggestive of ACS and were referred for further cardiac investigations. Of the remainder, five patients were medically managed for ACS, 38 patients with non-cardiac chest pain had no further tests. At 1 year follow-up, of the patients that did not undergo further investigations, 6 patients represented with ACS; there was no cardiac mortality.
  
  
  CONCLUSIONS
  Our data showed a number of patients that would be potentially missed with the implementation of a 50% troponin. However, this loss of sensitivity was mitigated by the use of clinical acumen.
authors.affiliation: Monash University, Eastern Health Clinical School, Victoria, Australia.
authors.forename: Jithin K
authors.initials: JK
authors.lastname: Sajeev
authors.affiliation: Monash University, Eastern Health Clinical School, Victoria, Australia.
authors.forename: Gishel
authors.initials: G
authors.lastname: New
authors.affiliation: Monash University, Eastern Health Clinical School, Victoria, Australia.
authors.forename: Louise
authors.initials: L
authors.lastname: Roberts
authors.affiliation: Monash University, Eastern Health Clinical School, Victoria, Australia.
authors.forename: Siddharth K
authors.initials: SK
authors.lastname: Menon
authors.affiliation: Monash University, Eastern Health Clinical School, Victoria, Australia.
authors.forename: Florence
authors.initials: F
authors.lastname: Gunawan
authors.affiliation: Monash University, Eastern Health Clinical School, Victoria, Australia.
authors.forename: Piyumi
authors.initials: P
authors.lastname: Wijesundera
authors.affiliation: Monash University, Eastern Health Clinical School, Victoria, Australia; Cardiology Department, Austin Hospital, Heidelberg, Victoria, Australia. Electronic address: Andrew.teh@easternhealth.org.au.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Teh
mesh_terms: D001315:Australia / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D002637:Chest Pain / Q000097:blood* / Q000175:diagnosis* / Q000453:epidemiology; D003324:Coronary Artery Disease / Q000097:blood* / Q000175:diagnosis* / Q000453:epidemiology; D004636:Emergency Service, Hospital / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009520:New Zealand / Q000453:epidemiology; D012189:Retrospective Studies; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T
keywords: Acute coronary syndrome; Delta; High sensitivity; Myocardial infarction; Troponin