title: Detection of post-exercise stunning by early gated SPECT myocardial perfusion imaging: results from the IAEA multi-center study.
abstract: BACKGROUND
  Transient post-ischemic LV dysfunction due to myocardial stunning in patients with coronary artery disease can be missed by conventional gated SPECT (GSPECT) acquisitions. The aim of this IAEA-sponsored multi-center study was to determine whether early post-exercise imaging is more likely to detect stunning than conventional without adversely affecting image quality or perfusion information.
  
  
  RESULTS
  Patients undergoing exercise/rest GSPECT were enrolled in this international multicenter study. Post-exercise studies were acquired at 15 ± 5 minutes after radiotracer injection (Stress-1) and repeated at 60 ± 15 minutes (Stress-2). Rest studies (R) were acquired at 60 minutes post injection. A core laboratory quantitatively assessed perfusion pattern and LV blinded to the acquisition time. Ischemia was defined as summed stress score (SDS) ≥4, and stunning was defined as the difference between rest and post-stress LVEF (Δ-LVEF). In the 229 patients enrolled into the study, both image quality and perfusion information were similar between Stress-1 and Stress-2. Post-stress LVEF was associated with both ischemia and time of acquisition, with a significant correlation between SDS and Δ-LVEF, which was stronger at Stress-1 than Stress-2 in the ischemic compared to the non-ischemic population (r = 0.23 vs 0.08, P = 0.10).
  
  
  CONCLUSIONS
  Early post-exercise imaging is feasible, and can potentially improve the detection of post-ischemic stunning without compromising image quality and perfusion data.
authors.affiliation: Department of Nuclear Medicine, Spanish Association Hospital, Montevideo, Uruguay.
authors.forename: Fernando
authors.initials: F
authors.lastname: Mut
authors.forename: Raffaele
authors.initials: R
authors.lastname: Giubbini
authors.forename: Joao
authors.initials: J
authors.lastname: Vitola
authors.forename: Lara
authors.initials: L
authors.lastname: Lusa
authors.forename: Dragana
authors.initials: D
authors.lastname: Sobic-Saranovic
authors.forename: Amalia
authors.initials: A
authors.lastname: Peix
authors.forename: Francesco
authors.initials: F
authors.lastname: Bertagna
authors.forename: Dieu
authors.initials: D
authors.lastname: Hang Bui
authors.forename: Carlos
authors.initials: C
authors.lastname: Cunha
authors.forename: Jerry
authors.initials: J
authors.lastname: Obaldo
authors.forename: Carlo
authors.initials: C
authors.lastname: Rodella
authors.forename: Luca
authors.initials: L
authors.lastname: Camoni
authors.forename: Diana
authors.initials: D
authors.lastname: Paez
authors.forename: Maurizio
authors.initials: M
authors.lastname: Dondi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods*; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D042241:Early Diagnosis; D005080:Exercise Test / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D017682:Myocardial Stunning / Q000000981:diagnostic imaging* / Q000209:etiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity