title: Improved outcome prediction by SPECT myocardial perfusion imaging after CT attenuation correction.
abstract: The aim of this study was to determine the impact of attenuation correction with CT (CT-AC) on the prognostic value of SPECT myocardial perfusion imaging (SPECT MPI).
  
  
  METHODS
  The summed stress score (SSS; 20-segment model) was obtained from filtered backprojection (FBP) and iterative reconstruction with CT-AC in 876 consecutive patients undergoing a 1-d stress-rest (99m)Tc-tetrofosmin SPECT MPI study for the evaluation of known or suspected coronary artery disease. Survival free of major adverse cardiac events (MACEs; cardiac death or nonfatal myocardial infarction) and survival free of any adverse cardiac events (including cardiac hospitalization, unstable angina, and late coronary revascularization) were analyzed by Kaplan-Meier analysis.
  
  
  RESULTS
  At a mean follow-up of 2.3 ± 0.6 y, a total of 184 adverse events occurred in 145 patients, including 35 MACEs (16 cardiac deaths [rate, 1.8%] and 19 nonfatal myocardial infarctions [rate, 2.2%]). With FBP, an SSS of 0-3 best distinguished patients with a low MACE rate (0.6%), followed by an SSS of 4-8 (4.3%), with increased MACE rate, and an SSS of 9-13 (3.8%), which was comparable. By contrast, with CT-AC the discrimination of low from intermediate MACE rate was best observed between an SSS of 0 (0%) and an SSS of 1-3 (3.7%), with a plateau at an SSS of 4-8 (3.2%).
  
  
  CONCLUSIONS
  CT-AC for SPECT MPI allows improved risk stratification. The prognostically relevant SSS cutoff is shifted toward lower values.
authors.affiliation: Cardiac Imaging, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Aju P
authors.initials: AP
authors.lastname: Pazhenkottil
authors.forename: Jelena-Rima
authors.initials: JR
authors.lastname: Ghadri
authors.forename: Rene N
authors.initials: RN
authors.lastname: Nkoulou
authors.forename: Mathias
authors.initials: M
authors.lastname: Wolfrum
authors.forename: Ronny R
authors.initials: RR
authors.lastname: Buechel
authors.forename: Silke M
authors.initials: SM
authors.lastname: Küest
authors.forename: Lars
authors.initials: L
authors.lastname: Husmann
authors.forename: Bernhard A
authors.initials: BA
authors.lastname: Herzog
authors.forename: Oliver
authors.initials: O
authors.lastname: Gaemperli
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Kaufmann
mesh_terms: D000241:Adenosine; D000368:Aged; D016757:Death, Sudden, Cardiac / Q000453:epidemiology; D018572:Disease-Free Survival; D004562:Electrocardiography; D023381:Endpoint Determination; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging*; D006331:Heart Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000453:epidemiology; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011237:Predictive Value of Tests; D011379:Prognosis; D019275:Radiopharmaceuticals; D012307:Risk Factors; D014055:Tomography, Emission-Computed / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin; D000241:Adenosine