title: Add-on tests for improving risk-stratification in emergency department patients with chest pain who are at low to moderate risk of 30-day major adverse cardiac events.
abstract: BACKGROUND
  Chest pain patients commonly present to emergency departments (ED), and require either hospital admission and/or lengthy diagnostic protocols to rule-out myocardial infarction. We aimed to identify the best combination of add-on tests to high-sensitivity cardiac troponin (hs-cTnT) for predicting 30-day major adverse cardiac events (MACE) in adult chest pain patients presenting to an ED with suspected acute coronary syndrome.
  
  
  METHODS
  This prospective observational study was conducted in the ED of a tertiary university hospital in Hong Kong, recruiting adult patients with chest pain of less than 24h duration, suspected with acute coronary syndrome (ACS), and had no history of coronary artery bypass grafting or stent insertion. Patients underwent triage assessment, electrocardiography, blood sampling for laboratory hs-cTnT, and Thrombolysis in Myocardial Infarction (TIMI) and HEART score assessment. The primary outcome was the number of patients with 30-day MACE.
  
  
  RESULTS
  602 consecutive patients were recruited and completed 30-day follow-up. A 30-day MACE occurred in 42 (7.0%) patients. Out of 12 possible models for stratifying patients at risk of 30-day MACE within 2h of ED arrival, a combination of electrocardiography (ECG) and one-time hs-cTnT (model 5) provided the simplest and most accurate model. A risk score of 0 to 5 was derived from raw coefficients of model 5. The risk score provided excellent calibration (P=0.91) and discrimination (AUC 0.87, 95% CI: 0.82 to 0.93).
  
  
  CONCLUSIONS
  Appropriate early risk-stratification of patients with chest pain and possible ACS using a combination of ECG and one-time hs-cTnT may improve efficiency of care.
authors.affiliation: Accident and Emergency Medicine Academic Unit, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: T H
authors.initials: TH
authors.lastname: Rainer
authors.affiliation: Accident and Emergency Medicine Academic Unit, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Y K
authors.initials: YK
authors.lastname: Leung
authors.affiliation: Department of Anaesthesia and Intensive Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: A
authors.initials: A
authors.lastname: Lee
authors.affiliation: Accident and Emergency Medicine Academic Unit, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: P Y
authors.initials: PY
authors.lastname: Chan
authors.affiliation: Accident and Emergency Medicine Academic Unit, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: N M
authors.initials: NM
authors.lastname: Cheng
authors.affiliation: Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: J K
authors.initials: JK
authors.lastname: Wong
authors.affiliation: Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: B P
authors.initials: BP
authors.lastname: Yan
authors.affiliation: Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: A T
authors.initials: AT
authors.lastname: Ahuja
authors.affiliation: Accident and Emergency Medicine Academic Unit, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong. Electronic address: cagraham@cuhk.edu.hk.
authors.forename: C A
authors.initials: CA
authors.lastname: Graham
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis / Q000453:epidemiology; D000368:Aged; D002637:Chest Pain / Q000175:diagnosis / Q000453:epidemiology; D003937:Diagnosis, Differential; D003955:Diagnostic Tests, Routine / Q000379:methods / Q000706:statistics & numerical data; D004562:Electrocardiography / Q000379:methods; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology; D012107:Research Design; D018570:Risk Assessment / Q000379:methods*; D013997:Time Factors; D014218:Triage / Q000379:methods
keywords: Acute coronary syndrome; ECG; HEART score; MACE; TIMI score; hs-cTnT