title: Prognostic utility of ischemic response in functional imaging tests (SPECT or stress echocardiography) in low-risk unstable angina patients.
abstract: BACKGROUND
  The aim of this study is to determine the ability of ischemic response in imaging stress tests (single-photon emission computed tomography [SPECT] or stress echocardiography [SE]) to predict events in low-risk unstable angina patients.
  
  
  METHODS
  Three hundred and fifty-nine patients with unstable angina (< 24 h), asymptomatic at admission, without ST-segment elevation or depression, normal troponins, and undergoing SPECT (n = 188) or SE (n = 171) during hospitalization (median = 1 day) were included. A positive imaging test (IMAGING+) was defined as the presence of reversible perfusion defects or wall motion abnormalities in at least 2 contiguous segments. Multivariate models were constructed using these results and clinical variables to predict events at 6 months.
  
  
  RESULTS
  Ninety-nine (27%) patients had IMAGING+, 72/188 (38%) in SPECT and 27/17 (16%) in SE (p < 0.0001). Events occurred in 84 (23%) patients: 4 had myocardial infarction, 47 new hospitalizations due to angina and 33 coronary artery revascularizations. Independent predictors of coronary artery disease were: IMAGING+ (OR: 6.4, 95% CI: 3.4-11.8, p < 0.0001), history of coronary artery disease (OR: 2.5, 95% CI: 1.2-5.2, p < 0.02) and TIMI risk (OR: 1.5, 95% CI: 1.1-2.2, p < 0.03).
  
  
  CONCLUSIONS
  In low-risk unstable angina patients, an ischemic response in functional stress tests (SPECT or SE) was associated with adverse events and severe coronary artery disease.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Trivi
authors.forename: Ricardo
authors.initials: R
authors.lastname: Ronderos
authors.forename: Alejandro
authors.initials: A
authors.lastname: Meretta
authors.affiliation: Instituto Cardiovascular de Buenos Aires. drconde@hotmail.com.
authors.forename: Diego
authors.initials: D
authors.lastname: Conde
authors.forename: Gustavo
authors.initials: G
authors.lastname: Avegliano
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy; D016009:Chi-Square Distribution; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009204:Myocardial Revascularization; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon