title: Assessment of patients with low-risk chest pain in the emergency department: Head-to-head comparison of exercise stress echocardiography and exercise myocardial SPECT.
abstract: OBJECTIVE
  The aim of the study was to compare head-to-head the performance of exercise tolerance test-stress echocardiography (ex-Echo) and exercise stress-perfusion nuclear imaging (exercise-single-photon emission computed tomography [ex-SPECT]) for the diagnosis of coronary artery disease (CAD) in patients evaluated at the chest pain unit with delay from chest pain (CP) onset.
  
  
  BACKGROUND
  As an early triage strategy for CAD in emergency medicine, ex-Echo could have the advantage of widespread availability and low costs.
  
  
  METHODS
  In the years 2000-2002, 503 consecutive patients (mean age 60 years) with recent (<24 hours) CP and nonischemic electrocardiogram (ECG), in whom CAD remained undiagnosed after first line 6-hour work-up including serum markers of myocardial injury and resting echocardiogram, underwent ex-Echo and ex-SPECT within 24 hours. Patients with (+)ex-Echo or (+)ex-SPECT or (+)ex-ECG or abnormal troponin I were referred to coronary angiography; otherwise, they were discharged and followed up. End points were coronary stenosis > or =50% and cardiovascular events at 6-month follow-up.
  
  
  RESULTS
  Ninety-nine patients (20%) had (+)ex-Echo and 121 (24%) (+)ex-SPECT; CAD was diagnosed in 81% and 67%, respectively; positive tests were concordant in 69%. In negative ex-Echo and ex-SPECT, final evidence of CAD emerged in 14 and 13, respectively. Ex-Echo demonstrated higher accuracy than ex-SPECT (93% +/- 1% vs 89% +/- 1%), optimal specificity (95% +/- 5% vs 90% +/- 5%), and positive predictive value (81% +/- 4% vs 67% +/- 4%); moreover, in the case of (-)ex-ECG, observed effective likelihood ratio indicates a (+)synergy between ex-ECG and ex-Echo.
  
  
  CONCLUSIONS
  Ex-Echo can be an effective diagnostic strategy in the early triage of CP patients, improving diagnosis in case of (-)ex-ECG and reducing unnecessary angiography number. Its drawback is represented by the 5% of missed diagnosis.
authors.affiliation: Emergency Medicine Department and Chest Pain Unit, Careggi Hospital, Florence, Italy. aaaconti@hotmail.com
authors.forename: Alberto
authors.initials: A
authors.lastname: Conti
authors.forename: Lucia
authors.initials: L
authors.lastname: Sammicheli
authors.forename: Chiara
authors.initials: C
authors.lastname: Gallini
authors.forename: Egidio Natalino
authors.initials: EN
authors.lastname: Costanzo
authors.forename: David
authors.initials: D
authors.lastname: Antoniucci
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Barletta
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D002637:Chest Pain / Q000209:etiology*; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D025401:Echocardiography, Stress / Q000379:methods; D004562:Electrocardiography; D004636:Emergency Service, Hospital; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012307:Risk Factors; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D015415:Biomarkers