title: Test of the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) for prehospital use.
abstract: OBJECTIVE
  To test diagnostic performance for acute cardiac ischemia (ACI) in a manually calculated and in a computerized, ECG-calculated ACI time-insensitive predictive instrument (ACI-TIPI) in prehospital chest pain patients.
  
  
  METHODS
  We carried out prospective inclusion and data acquisition with retrospective analysis. Over a 6-month period, 439 adult emergency medical services patients with chest pain underwent prehospital electrocardiography. Because of incomplete data, 77 cases were excluded, leaving a study sample of 362 patients. Excluded patients did not differ significantly with respect to age, sex, final diagnosis, or history of myocardial infarction, heart surgery, diabetes, or stroke. ACI-TIPI probabilities of ACI were computed on the basis of the prehospital ECGs as interpreted retrospectively and independently by two study investigators blinded to patient outcome, with a specially programmed electrocardiograph, and with a computer algorithm further modified by logistic-regression analysis.
  
  
  RESULTS
  Diagnostic performance on the basis of receiver operating characteristic (ROC) curve areas of the ACI-TIPI was scored, by the two physician readers, .73 and .74; and by ECG, .75. Patients with low ACI-TIPI probability (0% to 9%) had no acute myocardial infarctions, a 2.3% incidence of angina, and no prehospital life-threatening events.
  
  
  CONCLUSIONS
  ACI-TIPI probabilities of ACI as generated by a specially programmed electrocardiograph are comparable to those based on physician ECG interpretations and may be useful in the prehospital evaluation of chest pain.
authors.affiliation: Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
authors.forename: T P
authors.initials: TP
authors.lastname: Aufderheide
authors.forename: I
authors.initials: I
authors.lastname: Rowlandson
authors.forename: S W
authors.initials: SW
authors.lastname: Lawrence
authors.forename: E M
authors.initials: EM
authors.lastname: Kuhn
authors.forename: H P
authors.initials: HP
authors.lastname: Selker
mesh_terms: D000208:Acute Disease; D000368:Aged; D000465:Algorithms; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011336:Probability; D012372:ROC Curve; D012044:Regression Analysis; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D014218:Triage