title: Prediction of reversible ischemia after revascularization. Perfusion and metabolic studies with positron emission tomography.
abstract: BACKGROUND
  Accurate noninvasive determination of myocardial viability is of paramount importance for the clinical identification of patients who will benefit most from revascularization. The preserved metabolic activity in the myocardium, as studied with positron emission tomography (PET), has been considered a gold standard for this purpose. However, recent reports show that moderate hypoperfusion or stress-induced ischemia may represent reversible ischemia. The present study was undertaken to compare the value of perfusion and metabolic studies with PET for predicting improvement in wall motion after revascularization.
  
  
  RESULTS
  Of 61 patients who had regional asynergy and underwent PET before revascularization, 43 patients who had successful revascularization were included in the study. Each patient underwent rest-stress 13N-ammonia perfusion scans and 18F-fluorodeoxyglucose (FDG) scan at rest while in a fasting state. Reversible ischemia was considered to be present when the resting perfusion was > or = 50% of the peak value, stress-induced hypoperfusion was present, or an increase in FDG uptake was observed. Of 130 asynergy segments, 51 segments had improved wall motion after revascularization. The positive and negative predictive values for improvement in asynergy were 48% and 87% by the rest perfusion study, 63% (P = .05 versus the rest value) and 87% by the rest-stress perfusion study, and 76% (P < .01 versus the rest value) and 92% by the FDG study.
  
  
  CONCLUSIONS
  FDG PET provided the best predictive value for improvement in wall motion after revascularization. On the other hand, 13N-ammonia PET is useful for predicting nonreversible myocardial scarring when it shows severe hypoperfusion at rest or hypoperfusion without stress-induced ischemia.
authors.affiliation: Department of Radiology and Nuclear Medicine, Kyoto University Faculty of Medicine, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Tamaki
authors.forename: M
authors.initials: M
authors.lastname: Kawamoto
authors.forename: E
authors.initials: E
authors.lastname: Tadamura
authors.forename: Y
authors.initials: Y
authors.lastname: Magata
authors.forename: Y
authors.initials: Y
authors.lastname: Yonekura
authors.forename: R
authors.initials: R
authors.lastname: Nohara
authors.forename: S
authors.initials: S
authors.lastname: Sasayama
authors.forename: K
authors.initials: K
authors.lastname: Nishimura
authors.forename: T
authors.initials: T
authors.lastname: Ban
authors.forename: J
authors.initials: J
authors.lastname: Konishi
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D003847:Deoxyglucose / Q000031:analogs & derivatives; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000378:metabolism / Q000628:therapy*; D017202:Myocardial Ischemia / Q000209:etiology; D009204:Myocardial Revascularization / Q000009:adverse effects; D009206:Myocardium / Q000378:metabolism; D014055:Tomography, Emission-Computed
chemical_list: D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose