title: Utility of nuclear stress imaging for detecting coronary artery bypass graft disease.
abstract: BACKGROUND
  The value of single photon emission computed tomography stress myocardial perfusion imaging (SPECT-MPI) for detecting graft disease after coronary artery bypass surgery (CABG) has not been studied prospectively in an unselected cohort.
  
  
  METHODS
  Radial Artery Versus Saphenous Vein Graft Study is a Veterans Affairs Cooperative Study to determine graft patency rates after CABG surgery. Seventy-nine participants agreed to SPECT-MPI within 24 hours of their coronary angiogram, one-year after CABG. The choice of the stress protocol was made at the discretion of the nuclear radiologist and was either a symptom-limited exercise test (n = 68) or an adenosine infusion (n = 11). The SPECT-MPI results were interpreted independent of the angiographic results and estimates of sensitivity, specificity and accuracy were based on the prediction of a graft stenosis of ≥70% on coronary angiogram.
  
  
  RESULTS
  A significant stenosis was present in 38 (48%) of 79 patients and 56 (22%) of 251 grafts. In those stress tests with an optimal exercise heart rate response (>80% maximum predicted heart rate) (n = 26) sensitivity, specificity and accuracy of SPECT-MPI for predicting the graft stenosis was 77%, 69% and 73% respectively. With adenosine (n = 11) it was 75%, 57% and 64%, respectively. Among participants with a suboptimal exercise heart rate response, the sensitivity of SPECT-MPI for predicting a graft stenosis was <50%. The accuracy of SPECT-MPI for detecting graft disease did not vary significantly with ischemic territory.
  
  
  CONCLUSIONS
  Under optimal stress conditions, SPECT-MPI has a good sensitivity and accuracy for detecting graft disease in an unselected patient population 1 year post-CABG.
authors.affiliation: University of Minnesota, Minneapolis, MN, USA. baselaloul@hotmail.com
authors.forename: Basel
authors.initials: B
authors.lastname: Al Aloul
authors.forename: Mackenzi
authors.initials: M
authors.lastname: Mbai
authors.forename: Selcuk
authors.initials: S
authors.lastname: Adabag
authors.forename: Santiago
authors.initials: S
authors.lastname: Garcia
authors.forename: Hoang
authors.initials: H
authors.lastname: Thai
authors.forename: Steven
authors.initials: S
authors.lastname: Goldman
authors.forename: William
authors.initials: W
authors.lastname: Holman
authors.forename: Gulshan
authors.initials: G
authors.lastname: Sethi
authors.forename: Rosemary
authors.initials: R
authors.lastname: Kelly
authors.forename: Herbert B
authors.initials: HB
authors.lastname: Ward
authors.forename: Edward O
authors.initials: EO
authors.lastname: McFalls
mesh_terms: D000241:Adenosine; D000368:Aged; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003326:Coronary Circulation; D005080:Exercise Test; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000637:transplantation*; D012501:Saphenous Vein / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000637:transplantation*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D014481:United States; D014493:United States Department of Veterans Affairs; D014654:Vascular Patency; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine