title: A 1-h Combination Algorithm Allows Fast Rule-Out and Rule-In of Major Adverse Cardiac Events.
abstract: BACKGROUND
  A 1-h algorithm based on high-sensitivity cardiac troponin T (hs-cTnT) testing at presentation and again 1 h thereafter has been shown to accurately rule out acute myocardial infarction.
  
  
  OBJECTIVE
  The goal of the study was to evaluate the diagnostic accuracy of the 1-h algorithm when supplemented with patient history and an electrocardiogram (ECG) (the extended algorithm) for predicting 30-day major adverse cardiac events (MACE) and to compare it with the algorithm using hs-cTnT alone (the troponin algorithm).
  
  
  METHODS
  This prospective observational study enrolled consecutive patients presenting to the emergency department (ED) with chest pain, for whom hs-cTnT testing was ordered at presentation. Hs-cTnT results at 1 h and the ED physician's assessments of patient history and ECG were collected. The primary outcome was an adjudicated diagnosis of 30-day MACE defined as acute myocardial infarction, unstable angina, cardiogenic shock, ventricular arrhythmia, atrioventricular block, cardiac arrest, or death of a cardiac or unknown cause.
  
  
  RESULTS
  In the final analysis, 1,038 patients were included. The extended algorithm identified 60% of all patients for rule-out and had a higher sensitivity than the troponin algorithm (97.5% vs. 87.6%; p < 0.001). The negative predictive value was 99.5% and the likelihood ratio was 0.04 with the extended algorithm versus 97.8% and 0.17, respectively, with the troponin algorithm. The extended algorithm ruled-in 14% of patients with a higher sensitivity (75.2% vs. 56.2%; p < 0.001) but a slightly lower specificity (94.0% vs. 96.4%; p < 0.001) than the troponin algorithm. The rule-in arms of both algorithms had a likelihood ratio >10.
  
  
  CONCLUSIONS
  A 1-h combination algorithm allowed fast rule-out and rule-in of 30-day MACE in a majority of ED patients with chest pain and performed better than the troponin-alone algorithm.
authors.affiliation: Department of Internal and Emergency Medicine, Skåne University Hospital, Lund, Sweden; Department of Cardiology, Skåne University Hospital, Lund, Sweden; Department of Clinical Sciences at Lund, Lund University, Lund, Sweden. Electronic address: arash.mokhtari.0561@med.lu.se.
authors.forename: Arash
authors.initials: A
authors.lastname: Mokhtari
authors.affiliation: Department of Clinical Sciences at Lund, Lund University, Lund, Sweden; Division Specialised Local Health Care, Helsingborg General Hospital, Helsingborg, Sweden.
authors.forename: Catharina
authors.initials: C
authors.lastname: Borna
authors.affiliation: Department of Cardiology, Skåne University Hospital, Lund, Sweden.
authors.forename: Patrik
authors.initials: P
authors.lastname: Gilje
authors.affiliation: Department of Cardiology, Skåne University Hospital, Lund, Sweden.
authors.forename: Patrik
authors.initials: P
authors.lastname: Tydén
authors.affiliation: Department of Medical Sciences and Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden.
authors.forename: Bertil
authors.initials: B
authors.lastname: Lindahl
authors.affiliation: Department of Cardiology, Skåne University Hospital, Lund, Sweden.
authors.forename: Hans-Jörgen
authors.initials: HJ
authors.lastname: Nilsson
authors.affiliation: Department of Internal and Emergency Medicine, Skåne University Hospital, Lund, Sweden; Department of Clinical Sciences at Lund, Lund University, Lund, Sweden.
authors.forename: Ardavan
authors.initials: A
authors.lastname: Khoshnood
authors.affiliation: Occupational and Environmental Medicine, Lund University, Lund, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Björk
authors.affiliation: Department of Internal and Emergency Medicine, Skåne University Hospital, Lund, Sweden; Department of Clinical Sciences at Lund, Lund University, Lund, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Ekelund
mesh_terms: D000368:Aged; D000465:Algorithms; D002637:Chest Pain / Q000209:etiology; D004562:Electrocardiography; D004636:Emergency Service, Hospital; D005260:Female; D006331:Heart Diseases / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D020107:Troponin T / Q000097:blood
chemical_list: D020107:Troponin T
keywords: acute coronary syndrome; chest pain; diagnosis; myocardial infarction; sensitivity and specificity; unstable angina