title: Technetium-99m sestamibi for the assessment of myocardial salvage following reperfusion therapy in acute myocardial infarction.
abstract: BACKGROUND
  Reperfusion therapy with either thrombolysis or angioplasty has been shown to be beneficial in acute myocardial infarction. Tc-99m sestamibi is a myocardial tracer that can be used to assess myocardial salvage because of its property of very limited redistribution.
  
  
  METHODS
  To assess the feasibility of this technique locally, Tc-99m sestamibi was injected before and after reperfusion therapy with angioplasty (n = 11) or streptokinase (n = 18) in 29 patients with acute myocardial infarction (anterior = 25, inferior = 4). Single-photon emission computed tomography (SPECT) was performed within 4 hours of reperfusion and repeated 5 to 7 days later.
  
  
  RESULTS
  Initial perfusion defect size ranged from 6% to 78% (mean 36.3 +/- 18.7%), and final defect size from 0% to 50% of the left ventricle (mean 23.7 +/- 14.8%, P < 0.001). Patients with proximal left anterior descending artery (LAD) lesions had larger defects compared to those with mid LAD lesions (mean defect size 52% for pLAD versus 28% for mLAD, P < 0.013). However, there were wide variations in initial defect size (myocardium at risk) for a given infarct-related artery location. The mean decrease in defect size was 12% in the 28 patients with patent arteries compared to only 2% in the patient with an occluded artery (47% to 45%). There was no significant difference in amount of salvage between patients who had thrombolysis (mean 13%, P = 0.0003) and patients who had percutaneous transluminal coronary angioplasty (PTCA) (mean 12%, P = 0.005).
  
  
  CONCLUSIONS
  Assessment of myocardial salvage is feasible using Tc-99m sestamibi SPECT imaging. It allows for quantitation of myocardium at risk and the amount of myocardial salvage, which is not possible by angiography alone.
authors.affiliation: Department of Cardiology, National Heart Centre, Singapore.
authors.forename: F Y
authors.initials: FY
authors.lastname: Keng
authors.forename: T S
authors.initials: TS
authors.lastname: Chua
authors.forename: A S
authors.initials: AS
authors.lastname: Goh
authors.forename: E S
authors.initials: ES
authors.lastname: Ang
authors.forename: F X
authors.initials: FX
authors.lastname: Sundram
authors.forename: A T
authors.initials: AT
authors.lastname: Tan
mesh_terms: D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000379:methods; D011336:Probability; D016879:Salvage Therapy; D012680:Sensitivity and Specificity; D013300:Streptokinase / Q000627:therapeutic use*; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D005343:Fibrinolytic Agents; D017256:Technetium Tc 99m Sestamibi; D013300:Streptokinase