title: Effect of changes in perfusion defect size during serial regadenoson myocardial perfusion imaging on cardiovascular outcomes in high-risk patients.
abstract: BACKGROUND
  The prognostic value of single-photon emission computed tomography myocardial perfusion imaging (MPI) is well established. There is a paucity of data on the prognostic value of changes in perfusion defect size (PDS) on serial MPIs.
  
  
  METHODS
  From the MPI database at the University of Alabama at Birmingham, consecutive patients who underwent two regadenoson stress MPIs between July 2008 and March 2013 were identified. The MPIs were analyzed side-by-side using an automated software program for presence and change in PDS. Improvement in PDS was defined as a reduction ≥5% of left ventricle. A drop in left ventricular ejection fraction (LVEF) was defined as a decrease ≥5%. The primary outcome was a composite of death, myocardial infarction (MI), and coronary revascularization (CR).
  
  
  RESULTS
  There were 698 patients (61 ± 11 years, 53% male, 48% diabetes, 25% prior MI, 49% prior CR) who underwent two regadenoson MPIs within 16 ± 9 months for clinical indications. The primary outcome occurred in 167 (24%) patients (8% death, 9% MI, 15% CR) during 24 ± 16 months of follow-up after the second MPI. The MPIs were normal in both studies in 399 (57%, Group 1), showed improvement in 94 (14%, Group 2, PDS 15% ± 16% vs 28% ± 18%, P < .001) and no change or worsening in 205 patients (29%, Group 3, 28% ± 17% vs 20% ± 17%, P < .001). The best outcomes were seen in Group 1 and the worst in Group 3 (log-rank P < .001). Similar trends were seen for the components of the primary outcome (P = .04 for death, P < .001 for MI, P < .001 for CR). In a Cox-regression model that adjusted for baseline factors including PDS and LVEF on initial MPI, the hazard ratios for primary outcome were 2.0 (P = .02) and 3.9 (P < .001) for Groups 2 and 3 compared to Group 1, respectively. In addition, an LVEF drop ≥5% was independently associated with the primary outcome (HR 1.5, P = .01).
  
  
  CONCLUSIONS
  Changes in PDS and LVEF on serial MPIs provide incremental prognostic information to initial and follow-up MPI findings. Lack of improvement or an increase in PDS and a drop in LVEF identify high-risk patients.
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Lyons Harrison Research Building 314, 1900 University BLVD, Birmingham, AL, 35294, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: El-Hajj
authors.affiliation: Division of Cardiovascular Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Wael A
authors.initials: WA
authors.lastname: AlJaroudi
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Lyons Harrison Research Building 314, 1900 University BLVD, Birmingham, AL, 35294, USA.
authors.forename: Ayman
authors.initials: A
authors.lastname: Farag
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Lyons Harrison Research Building 314, 1900 University BLVD, Birmingham, AL, 35294, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Bleich
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Lyons Harrison Research Building 314, 1900 University BLVD, Birmingham, AL, 35294, USA.
authors.forename: Padma
authors.initials: P
authors.lastname: Manaoragada
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Lyons Harrison Research Building 314, 1900 University BLVD, Birmingham, AL, 35294, USA.
authors.forename: Ami E
authors.initials: AE
authors.lastname: Iskandrian
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Lyons Harrison Research Building 314, 1900 University BLVD, Birmingham, AL, 35294, USA. fadihage@uab.edu.|Section of Cardiology, Birmingham Veterans Administration Medical Center, Birmingham, AL, USA. fadihage@uab.edu.
authors.forename: Fadi G
authors.initials: FG
authors.lastname: Hage
mesh_terms: D000407:Alabama / Q000453:epidemiology; D015897:Comorbidity; D003287:Contrast Media / Q000008:administration & dosage; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000601:surgery; D005080:Exercise Test / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000601:surgery; D055414:Myocardial Perfusion Imaging / Q000706:statistics & numerical data*; D062645:Percutaneous Coronary Intervention / Q000401:mortality; D015995:Prevalence; D011379:Prognosis; D011687:Purines / Q000008:administration & dosage*; D011720:Pyrazoles / Q000008:administration & dosage*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D015996:Survival Rate; D014665:Vasodilator Agents
chemical_list: D003287:Contrast Media; D011687:Purines; D011720:Pyrazoles; D014665:Vasodilator Agents; C430916:regadenoson
keywords: Myocardial perfusion imaging; outcomes; regadenoson; serial