title: Assessing risk in acute chest pain: The value of stress myocardial perfusion imaging in patients admitted through the emergency department.
abstract: BACKGROUND
  To prospectively assess the clinical value of stress-gated myocardial single photon emission computed tomography (SPECT) for triaging patients admitted through the emergency department (ED) with acute chest pain (ACP).
  
  
  METHODS
  Prospective, observational cohort study in 1,576 consecutive patients who were evaluated for ACP over a 29-month period. Stress SPECT was performed within 24 hours of admission from the ED. Analysis included quantification of total and ischemic left ventricular perfusion defect size (PDS). Cardiac events were defined as an acute coronary syndrome during the index hospitalization or in follow-up over 7.3 ± 2.8 months.
  
  
  RESULTS
  Eighty-five cardiac events occurred in 77 patients (4.9%). SPECT was abnormal in 135 patients (8.6%) of whom 83 (61.5%) had a reversible defect. Event rates were significantly higher in patients with an abnormal (40%) versus a normal (1.6%) SPECT (P < .0001); and in those with a (1) large (>15%) versus small (≤15%) PDS (50.0% vs 33.7%, P = .05) and (2) large (>10%) versus small (≤10%) ischemic PDS (87.5% vs 42.4%, P < .0001, respectively). SPECT best predicted cardiac events by multivariate analysis. The addition of SPECT to clinical variables significantly improved overall risk prediction (global χ(2) 103.6 vs 207.1, P < .001).
  
  
  CONCLUSIONS
  Stress SPECT can accurately assess risk in a heterogeneous group of patients with ACP of unclear cardiac etiology, and beyond that provided by a clinical risk assessment alone. Our results support the use of stress SPECT for identifying very low-risk ACP patients with normal study results who can be safely discharged home.
authors.affiliation: Methodist DeBakey Heart and Vascular Center and The Methodist Hospital Research Institute, The Methodist Hospital, Houston, TX 77030, USA.
authors.forename: Faisal
authors.initials: F
authors.lastname: Nabi
authors.forename: Su Min
authors.initials: SM
authors.lastname: Chang
authors.forename: Jiaqiong
authors.initials: J
authors.lastname: Xu
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Gigliotti
authors.forename: John J
authors.initials: JJ
authors.lastname: Mahmarian
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002637:Chest Pain / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015897:Comorbidity; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D055414:Myocardial Perfusion Imaging / Q000706:statistics & numerical data*; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013781:Texas / Q000453:epidemiology; D055815:Young Adult