title: Accuracy of imaging technologies in the diagnosis of acute cardiac ischemia in the emergency department: a meta-analysis.
abstract: OBJECTIVE
  We sought to quantitatively evaluate the evidence on the diagnostic performance of imaging technologies (including rest and stress echocardiography and technetium-99m sestamibi scanning) for the diagnosis of acute cardiac ischemia and acute myocardial infarction in the emergency department.
  
  
  METHODS
  We conducted a systematic review and meta-analysis of the English-language literature published between 1966 and December 1998. Both prospective and retrospective studies qualified for the assessment of diagnostic performance. Diagnostic performance was assessed by means of random-effect estimates of test sensitivity, specificity, and the diagnostic odds ratio and was summarized by using summary receiver-operating characteristic curves.
  
  
  RESULTS
  Diagnostic accuracy was evaluated in 10 studies of rest echocardiography, 2 studies of dobutamine stress echocardiography, and 6 studies of technetium-99m sestamibi scanning. However, only 3 rest echocardiography and 5 technetium-99m sestamibi studies evaluated patients strictly in the ED setting. Patient populations were often highly selected to represent low- or moderate-risk groups. When limited to ED studies, rest echocardiography showed excellent sensitivity of 93% (95% CI, 81% to 97%) and good specificity of 66% (95% CI, 43% to 83%). The results were similar when all studies were considered, including data from reports of admitted patients and patients sent to the cardiac care unit. There was insufficient literature on stress echocardiography in the ED to properly assess the technology. Technetium-99m sestamibi scanning also showed excellent sensitivity (range, 91.5% to 100%) and good specificity (range, 49.3% to 84.4%) for acute myocardial infarction; for acute cardiac ischemia, the random-effects pooled sensitivity was 89% (95% CI, 73% to 96%), and the pooled specificity was 77% (95% CI, 63% to 87%).
  
  
  CONCLUSIONS
  For selected low- and moderate-risk patient groups, echocardiography and technetium-99m sestamibi imaging appear to have very good diagnostic performance with a similar sensitivity and specificity profile. More evidence should be accumulated on their performance specifically in the ED setting.
authors.affiliation: Evidence-based Practice Center, Division of Clinical Care Research, New England Medical Center, Boston, MA 02115, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Ioannidis
authors.forename: D
authors.initials: D
authors.lastname: Salem
authors.forename: P W
authors.initials: PW
authors.lastname: Chew
authors.forename: J
authors.initials: J
authors.lastname: Lau
mesh_terms: D000208:Acute Disease; D015982:Bias; D003952:Diagnostic Imaging / Q000379:methods* / Q000592:standards*; D004452:Echocardiography / Q000592:standards; D004638:Emergency Treatment / Q000379:methods* / Q000592:standards*; D019317:Evidence-Based Medicine; D005080:Exercise Test / Q000592:standards; D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000453:epidemiology; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000453:epidemiology; D016017:Odds Ratio; D015995:Prevalence; D011446:Prospective Studies; D015203:Reproducibility of Results; D012107:Research Design; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D013673:Technology Assessment, Biomedical
chemical_list: D017256:Technetium Tc 99m Sestamibi