title: Value of vasodilator left ventricular ejection fraction reserve in evaluating the magnitude of myocardium at risk and the extent of angiographic coronary artery disease: a 82Rb PET/CT study.
abstract: Our aim was to determine the value of vasodilator left ventricular ejection fraction (LVEF) reserve (stress ejection fraction - rest ejection fraction) in evaluating the magnitude of myocardium at risk and the anatomic extent of underlying severe coronary artery disease (CAD).
  
  
  METHODS
  We studied 510 consecutive patients with suspected CAD undergoing gated rest and vasodilator stress (82)Rb PET/CT. Patients were categorized as having no perfusion abnormalities, mild, moderate, or severe reversible perfusion defects. In a subgroup of 68 patients with coronary angiography, patients were categorized as having 0-vessel, 1-vessel, 2-vessel, or left main/3-vessel disease.
  
  
  RESULTS
  Patients without coronary risk factors who comprised our control group as well as patients with coronary risk factors and normal perfusion demonstrated a high LVEF reserve (7% +/- 7% and 5% +/- 6%, respectively). The mean LVEF reserve was negative (-0.2% +/- 8%) in patients with severe reversible defects and in patients with 3-vessel (-6% +/- 8%) and left main (-8% +/- 5%) disease. Among the clinical and scintigraphic variables studied, male sex, rest ejection fraction, and increasing magnitude of myocardium at risk predicted a lower LVEF reserve, whereas LVEF reserve was the only independent predictor of left main/3-vessel disease (P = 0.008). An LVEF reserve of more than +5% had a positive predictive value of only 41% but a negative predictive value of 97% for excluding severe left main/3-vessel CAD.
  
  
  CONCLUSIONS
  During (82)Rb PET/CT, LVEF increases with vasodilator stress in patients without significant stress-induced perfusion defects or severe left main/3-vessel CAD. A high LVEF reserve appears to be an excellent tool to exclude left main/3-vessel CAD noninvasively.
authors.affiliation: Divisions of Nuclear Medicine, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. sdorbala@partners.org
authors.forename: Sharmila
authors.initials: S
authors.lastname: Dorbala
authors.forename: Divya
authors.initials: D
authors.lastname: Vangala
authors.forename: Uchechukwu
authors.initials: U
authors.lastname: Sampson
authors.forename: Atul
authors.initials: A
authors.lastname: Limaye
authors.forename: Raymond
authors.initials: R
authors.lastname: Kwong
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Di Carli
mesh_terms: D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000503:physiopathology*; D003326:Coronary Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012414:Rubidium Radioisotopes; D013318:Stroke Volume; D014057:Tomography, X-Ray Computed; D014665:Vasodilator Agents / Q000494:pharmacology*; D016277:Ventricular Function, Left
chemical_list: D012414:Rubidium Radioisotopes; D014665:Vasodilator Agents