title: Incremental prognostic value of gated Rb-82 positron emission tomography myocardial perfusion imaging over clinical variables and rest LVEF.
abstract: OBJECTIVE
  This investigation sought to study the incremental value of gated rubidium (Rb)-82 positron emission tomography (PET) myocardial perfusion imaging (MPI) over clinical variables for predicting survival and future cardiac events.
  
  
  BACKGROUND
  The prognostic value of Rb-82 PET-MPI and left ventricular ejection fraction (LVEF) reserve (stress minus rest LVEF) is not well defined.
  
  
  METHODS
  1,432 consecutive patients undergoing gated rest/vasodilator stress rubidium-82 PET were followed up for at least 1 year. Of these, rest and peak stress LVEF and LVEF reserve were available in 985 patients. Cardiac events (CE) including cardiac death or nonfatal myocardial infarction and all-cause death were assessed.
  
  
  RESULTS
  Over a mean follow-up of 1.7 +/- 0.7 years, 83 (5.8%) CE and 140 (9.7%) all-cause death were observed. There was an increase in risk for both end points with an increasing percentage of abnormal and ischemic myocardium. With normal, mild, moderate, or severely ischemic scans, the observed annualized rates of CE were 0.7%, 5.5%, 5%, and 11% and of all-cause death were 3.3%, 7.2%, 6.9%, and 12.5%, respectively. In 985 patients with peak stress gated data, the observed annualized rates of CE (2.1% vs. 5.3%, p < 0.001) and all-cause death (4.3% vs. 9.2%, p < 0.001) were higher in patients with an LVEF reserve <0% compared with those with an LVEF reserve >or=0%. On Cox proportional hazards analysis, after consideration of clinical, historical, and rest LVEF information, stress PET results and LVEF reserve yielded incremental prognostic value with respect to both CE and all-cause death.
  
  
  CONCLUSIONS
  Vasodilator stress Rb-82 PET-MPI provides incremental prognostic value to historical/clinical variables and rest LVEF to predict survival free of CE and all-cause death. An increasing percentage of ischemia on PET-MPI is associated with an increase in the risk of CE and all-cause death. Left ventricular ejection fraction reserve provides significant independent and incremental value to Rb-82 MPI for predicting the risk of future adverse events.
authors.affiliation: Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. sdorbala@partners.org
authors.forename: Sharmila
authors.initials: S
authors.lastname: Dorbala
authors.forename: Rory
authors.initials: R
authors.lastname: Hachamovitch
authors.forename: Zelmira
authors.initials: Z
authors.lastname: Curillova
authors.forename: Deepak
authors.initials: D
authors.lastname: Thomas
authors.forename: Divya
authors.initials: D
authors.lastname: Vangala
authors.forename: Raymond Y
authors.initials: RY
authors.lastname: Kwong
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Di Carli
mesh_terms: D000368:Aged; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology; D004176:Dipyridamole; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009206:Myocardium / Q000473:pathology*; D049268:Positron-Emission Tomography; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012414:Rubidium Radioisotopes; D012720:Severity of Illness Index; D013318:Stroke Volume; D013997:Time Factors; D014665:Vasodilator Agents; D016277:Ventricular Function, Left
chemical_list: D012414:Rubidium Radioisotopes; D014665:Vasodilator Agents; D004176:Dipyridamole