title: Noninvasive imaging of myocardial reperfusion injury using leukocyte-targeted contrast echocardiography.
abstract: BACKGROUND
  We hypothesized that myocardial contrast echocardiography (MCE) with leukocyte-targeted microbubbles could temporally and spatially characterize the severity of postischemic myocardial inflammation.
  
  
  RESULTS
  In 9 open-chest dogs, either the left anterior descending or left circumflex coronary artery was occluded for 90 minutes (n=6), while the remaining dogs served as non-ischemic controls. During occlusion, MCE was performed to determine the risk area (RA) and regions supplied by collateral flow. Myocardial inflammation was assessed 5, 60, and 120 minutes after reflow by MCE imaging of leukocyte-targeted (phosphatidylserine-containing) lipid microbubbles. The spatial extent and severity of inflammation were also assessed by radionuclide imaging of the neutrophil-avid tracer 99mTcRP517 and tissue myeloperoxidase activity. Early after reflow, MCE detected inflammation throughout the entire risk area, the extent of which decreased over time due to reduced signal in collateral-supplied regions. The spatial extent of inflammation late after reflow was similar for MCE and radionuclide imaging. The severity of inflammation in the infarct zone, the noninfarcted risk area, and collateral-supplied territories determined by quantitative MCE correlated well with myeloperoxidase activity (r=0.81).
  
  
  CONCLUSIONS
  MCE with leukocyte-targeted microbubbles can temporally assess the severity and extent of postischemic myocardial inflammation and could be used to evaluate new treatment strategies designed to limit inflammation in acute coronary syndromes.
authors.affiliation: Cardiovascular Division, University of Virginia School of Medicine, Charlottesville, Va, USA.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Christiansen
authors.forename: Howard
authors.initials: H
authors.lastname: Leong-Poi
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Klibanov
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Kaul
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Lindner
mesh_terms: D000818:Animals; D004285:Dogs; D004452:Echocardiography / Q000379:methods*; D007249:Inflammation / Q000000981:diagnostic imaging; D007700:Kinetics; D007962:Leukocytes / Q000000981:diagnostic imaging*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging; D015428:Myocardial Reperfusion Injury / Q000000981:diagnostic imaging* / Q000201:enzymology; D009195:Peroxidase / Q000032:analysis; D011877:Radionuclide Imaging
chemical_list: D009195:Peroxidase