title: Simplified Predictive Instrument to Rule Out Acute Coronary Syndromes in a High-Risk Population.
abstract: BACKGROUND
  It is unclear whether diagnostic protocols based on cardiac markers to identify low-risk chest pain patients suitable for early release from the emergency department can be applied to patients older than 65 years or with traditional cardiac risk factors.
  
  
  RESULTS
  In a single-center retrospective study of 231 consecutive patients with high-risk factor burden in which a first cardiac troponin (cTn) level was measured in the emergency department and a second cTn sample was drawn 4 to 14 hours later, we compared the performance of a modified 2-Hour Accelerated Diagnostic Protocol to Assess Patients with Chest Pain Using Contemporary Troponins as the Only Biomarker (ADAPT) rule to a new risk classification scheme that identifies patients as low risk if they have no known coronary artery disease, a nonischemic electrocardiogram, and 2 cTn levels below the assay's limit of detection. Demographic and outcome data were abstracted through chart review. The median age of our population was 64 years, and 75% had Thrombosis In Myocardial Infarction risk score ≥2. Using our risk classification rule, 53 (23%) patients were low risk with a negative predictive value for 30-day cardiac events of 98%. Applying a modified ADAPT rule to our cohort, 18 (8%) patients were identified as low risk with a negative predictive value of 100%. In a sensitivity analysis, the negative predictive value of our risk algorithm did not change when we relied only on undetectable baseline cTn and eliminated the second cTn assessment.
  
  
  CONCLUSIONS
  If confirmed in prospective studies, this less-restrictive risk classification strategy could be used to safely identify chest pain patients with more traditional cardiac risk factors for early emergency department release.
authors.affiliation: Division of Cardiology, Duke University Medical Center, Durham, NC (A.C.F., K.N.).
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Fanaroff
authors.affiliation: Department of Medicine, Durham VA Medical Center, Durham, NC (R.D.S., S.V.R.).
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Schulteis
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, NC (K.S.P., S.V.R., K.N.).
authors.forename: Karen S
authors.initials: KS
authors.lastname: Pieper
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, NC (K.S.P., S.V.R., K.N.) Department of Medicine, Durham VA Medical Center, Durham, NC (R.D.S., S.V.R.).
authors.forename: Sunil V
authors.initials: SV
authors.lastname: Rao
authors.affiliation: Division of Cardiology, Duke University Medical Center, Durham, NC (A.C.F., K.N.) Duke Clinical Research Institute, Duke University Medical Center, Durham, NC (K.S.P., S.V.R., K.N.).
authors.forename: L Kristin
authors.initials: LK
authors.lastname: Newby
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications / Q000175:diagnosis*; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002637:Chest Pain / Q000209:etiology; D003661:Decision Support Techniques; D004562:Electrocardiography; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D019209:Troponin C / Q000097:blood
chemical_list: D015415:Biomarkers; D019209:Troponin C
keywords: acute coronary syndromes; chest pain; coronary disease; emergency department; risk classification