title: Positive predictive value of an elevated cardiac troponin for type I myocardial infarction in ED patients based on the chief complaint.
abstract: BACKGROUND
  Cardiac troponin testing is used to aid the diagnosis of myocardial infarction (MI) in the emergency department (ED) for patients who present with a range of symptoms. From a clinical perspective, the distinction between MI due to acute coronary artery thrombosis (type I MI) and other forms of direct and secondary myocardial injury (type II MI) is very important. However, the positive predictive value (PPV) of an elevated troponin for diagnosing type I MI, based on clinical history, has not been described. The objective of this study was to determine the PPV of an elevated troponin for type I MI based on the ED chief complaint.
  
  
  METHODS
  We retrospectively reviewed the medical records of 1772 consecutive patients who had a troponin ordered in the ED at a tertiary care center over the period of March 1, 2013, to April 30, 2013. The chief complaint was based on official ED coding. For patients with a positive troponin, 2 authors independently reviewed the electronic medical record pertaining to the index encounter and subsequent hospitalization to adjudicate the cause.
  
  
  RESULTS
  There was a significant association between the PPV of an elevated troponin for type I MI and the chief complaint. Patients with a chief complaint of chest pain were significantly more likely to have a type I MI compared to those without (PPV 84% vs 20%; Adjusted Odds Ratio (AOR), 14.31; P < .0001). There was also a significant association between the rate of type I MI and the chief complaint in all patients who had a troponin drawn. Patients with a chief complaint of chest pain were significantly more likely to have a type I MI compared to those without (PPV 9.8% vs 1.3%; AOR, 7.34; P < .0001).
  
  
  CONCLUSIONS
  Applying information on the PPV of troponin for type I MI based on the clinical history could improve troponin utilization and clinical decision making.
authors: Division of Cardiology, Heart and Vascular Institute, Penn State Milton S. Hershey Medical Center, Hershey, PA.
authors: Ronald
authors: R
authors: Maag
authors: Division of Outcomes Research and Quality, Department of Surgery, Penn State Milton S. Hershey Medical Center, Hershey, PA.
authors: Susie
authors: S
authors: Sun
authors: Penn State Milton S. Hershey Medical College, Hershey, PA.
authors: Michael
authors: M
authors: Hannon
authors: Department of Internal Medicine, Penn State Milton S. Hershey Medical Center, Hershey, PA.
authors: Rhian
authors: R
authors: Davies
authors: Division of Cardiology, Heart and Vascular Institute, Penn State Milton S. Hershey Medical Center, Hershey, PA.
authors: Peter
authors: P
authors: Alagona
authors: Division of Cardiology, Heart and Vascular Institute, Penn State Milton S. Hershey Medical Center, Hershey, PA; Division of Health Services and Behavioral Research, Department of Public Health Sciences, Penn State Milton S. Hershey Medical Center, Hershey, PA. Electronic address: afoy@hmc.psu.edu.
authors: Andrew
authors: A
authors: Foy
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I