title: Normal stress-only versus standard stress/rest myocardial perfusion imaging: similar patient mortality with reduced radiation exposure.
abstract: OBJECTIVE
  The aim of this study was to determine whether a normal stress-only single-photon emission computed tomographic myocardial perfusion tomography (SPECT) study confers the same prognosis as a normal SPECT on the basis of evaluation of stress and rest images.
  
  
  BACKGROUND
  Current guidelines recommend stress and rest imaging to confirm that a SPECT study is normal.
  
  
  METHODS
  We determined all-cause mortality in 16,854 consecutive patients who had a normal gated stress SPECT. Median follow-up was 4.5 years. A stress-only protocol was used in 8,034 patients (47.6%), whereas 8,820 (52.4%) had both stress and rest imaging.
  
  
  RESULTS
  The overall unadjusted annual mortality rate in patients who had a normal SPECT with a stress-only protocol was lower than in those who required additional rest imaging (2.57% vs. 2.92%, p = 0.02). After adjustment for baseline clinical characteristics no significant differences in patient mortality were seen between the 2 imaging protocols, but the stress-only group received a 61% lower radiopharmaceutical dosage. Independent predictors of worse survival included increasing age, male sex, diabetes, history of coronary artery disease, and inability to exercise (all p < 0.001) but not the type of SPECT protocol used to image patients.
  
  
  CONCLUSIONS
  Patients determined to have a normal SPECT on the basis of stress imaging alone have a similar mortality rate as those who have a normal SPECT on the basis of evaluation of both stress and rest images. Our results support that additional rest imaging is not required in patients who have a normally appearing initial stress study. A significant reduction in radiation exposure can be achieved with such an approach.
authors.affiliation: Methodist DeBakey Heart and Vascular Center, Houston, Texas 77030, USA.
authors.forename: Su Min
authors.initials: SM
authors.lastname: Chang
authors.forename: Faisal
authors.initials: F
authors.lastname: Nabi
authors.forename: Jiaqiong
authors.initials: J
authors.lastname: Xu
authors.forename: Umara
authors.initials: U
authors.lastname: Raza
authors.forename: John J
authors.initials: JJ
authors.lastname: Mahmarian
mesh_terms: D000241:Adenosine; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000401:mortality*; D004280:Dobutamine; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D004280:Dobutamine; D000241:Adenosine