title: Prognostic value of myocardium perfusion imaging with a new reconstruction algorithm.
abstract: BACKGROUND
  It has been demonstrated that a new reconstruction algorithm for myocardium perfusion imaging (MPI) allows faster acquisition with similar accuracy. The prognostic value of MPI performed with this software and short acquisition time is unknown.
  
  
  METHODS
  To determine the prognostic value we followed 3184 consecutive MPI patients between March 2008 and March 2010. A 2-day protocol with low dose 99mTc-MIBI (10-12 mCi) and a 6-minute acquisition was used. Exercise stress was used in 62.6% of the studies. Scans were reconstructed using the software "Evolution for cardiac". Perfusion defects were quantified by summed stress score (SSS) and categorized in four groups: SSS0 = 0; SSS1 = 1-3; SSS2 = 4-8; and SSS3 ≥ 9. Patients were phone contacted every 6 months for follow up and hard events were defined as death or myocardial infarction (MI) and total events as hard events plus late revascularization.
  
  
  RESULTS
  The mean radiation dose was <7 mSv/patient. Mean F/U was 33 ± 20 months; 140 of the patients were lost to follow up and 86 were censored due early revascularization (<60 days after MPS). There were 140 hard events: 89 deaths and 51 MI. Mean age was 61.5 ± 12.3 years and 57.7% were male. Hard event rate was 0.8%/year in patients with normal MPS and 3.7%/year in those with abnormal MPS. Patients with larger defects had nine times more hard events than patients with SSS = 0 (14.2% vs 1.6%). Revascularization was more frequent in patients with abnormal MPS than normal MPS (21.7% vs 3.9%; P < 0.001). Cox proportional hazard analysis showed that SSS was an independent predictor of hard events and revascularization.
  
  
  CONCLUSIONS
  The use of reduced-dose, fast myocardial perfusion SPECT and the new processing algorithm lowers acquisition time and radiation exposure compared to conventional SPECT without compromising the well-established prognostic value of MPI.
authors.forename: Ronaldo
authors.initials: R
authors.lastname: Lima
authors.affiliation: Universidade Federal do Rio de Janeiro, Cardiology, Rio de Janeiro, Brazil, ronlima@hotmail.com.
authors.forename: Lima
authors.initials: L
authors.lastname: Ronaldo
authors.forename: Andrea
authors.initials: A
authors.lastname: De Lorenzo
authors.forename: De Lorenzo
authors.initials: de L
authors.lastname: Andrea
authors.forename: Gabriel
authors.initials: G
authors.lastname: Camargo
authors.forename: Camargo
authors.initials: C
authors.lastname: Gabriel
authors.forename: Gabriel
authors.initials: G
authors.lastname: Oliveira
authors.forename: Oliveira
authors.initials: O
authors.lastname: Gabriel
authors.forename: Thiago
authors.initials: T
authors.lastname: Reis
authors.forename: Reis
authors.initials: R
authors.lastname: Thiago
authors.forename: Thais
authors.initials: T
authors.lastname: Peclat
authors.forename: Peclat
authors.initials: P
authors.lastname: Thais
authors.forename: Tamara
authors.initials: T
authors.lastname: Rothstein
authors.forename: Rothstein
authors.initials: R
authors.lastname: Tamara
authors.forename: Ilan
authors.initials: I
authors.lastname: Gottlieb
authors.forename: Gottlieb
authors.initials: G
authors.lastname: Ilan
mesh_terms: D000368:Aged; D000465:Algorithms; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009204:Myocardial Revascularization; D010477:Perfusion; D011379:Prognosis; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D016896:Treatment Outcome