title: Distal coronary embolization following acute myocardial infarction increases early infarct size and late left ventricular wall thinning in a porcine model.
abstract: BACKGROUND
  Distal coronary embolization (DCE) of thrombotic material occurs frequently during percutaneous interventions for acute myocardial infarction and can alter coronary flow grades. The significance of DCE on infarct size and myocardial function remains unsettled. The aims of this study were to evaluate the effects of DCE sufficient to cause no-reflow on infarct size, cardiac function and ventricular remodeling in a porcine acute myocardial infarction model.
  
  
  RESULTS
  Female Yorkshire pigs underwent 60 min balloon occlusion of the left anterior descending coronary artery followed by reperfusion and injection of either microthrombi (prepared from autologous porcine blood) sufficient to cause no-reflow (DCE), or saline (control). Animals were sacrificed at 3 h (n = 5), 3 days (n = 20) or 6 weeks (n = 20) post-AMI. Cardiovascular magnetic resonance (CMR), serum troponin-I, and cardiac gelatinase (MMP) and survival kinase (Akt) activities were assessed. At 3d, DCE increased infarct size (CMR: 18.8% vs. 14.5%, p = 0.04; serum troponin-I: 13.3 vs. 6.9 ng/uL, p < 0.05) and MMP-2 activity levels (0.81 vs. 0.49, p = 0.002), with reduced activation of Akt (0.06 versus 0.26, p = 0.02). At 6 weeks, there were no differences in infarct size, ventricular volume or ejection fraction between the two groups, although infarct transmurality (70% vs. 57%, p< 0.04) and ventricular thinning (percent change in mid anteroseptal wall thickness:-25.6% vs. 0.7%, p = 0.03) were significantly increased in the DCE group.
  
  
  CONCLUSIONS
  DCE increased early infarct size, but without affecting later infarct size, cardiac function or ventricular volumes. The significance of the later remodelling changes (ventricular thinning and transmurality) following DCE, possibly due to changes in MMP-2 activity and Akt activation, merits further study.
authors.affiliation: Schulich Heart Centre, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Room D-406, Toronto, ON, M4N 3M5, Canada. reuben.thomas@mail.utoronto.ca.|University of Toronto, Toronto, Canada. reuben.thomas@mail.utoronto.ca.
authors.forename: Reuben M
authors.initials: RM
authors.lastname: Thomas
authors.affiliation: Schulich Heart Centre, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Room D-406, Toronto, ON, M4N 3M5, Canada. vnlover@hanmail.net.|University of Toronto, Toronto, Canada. vnlover@hanmail.net.|Korea University Ansan Hospital, Ansan, Korea. vnlover@hanmail.net.
authors.forename: Sang Yup
authors.initials: SY
authors.lastname: Lim
authors.affiliation: Schulich Heart Centre, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Room D-406, Toronto, ON, M4N 3M5, Canada. beipingqiang@yahoo.com.|University of Toronto, Toronto, Canada. beipingqiang@yahoo.com.
authors.forename: Beiping
authors.initials: B
authors.lastname: Qiang
authors.affiliation: Schulich Heart Centre, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Room D-406, Toronto, ON, M4N 3M5, Canada. uziosherov@yahoo.com.|Barzilai Medical Centre, Ashkelon, Israel. uziosherov@yahoo.com.
authors.forename: Azriel B
authors.initials: AB
authors.lastname: Osherov
authors.affiliation: Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada. nghugre@gmail.com.|University of Toronto, Toronto, Canada. nghugre@gmail.com.
authors.forename: Nilesh R
authors.initials: NR
authors.lastname: Ghugre
authors.affiliation: Toronto General Research Institute, Toronto, Canada. h.noyanashraf@utoronto.ca.|University of Toronto, Toronto, Canada. h.noyanashraf@utoronto.ca.
authors.forename: Hossein
authors.initials: H
authors.lastname: Noyan
authors.affiliation: Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada. xiuling.qi@sri.utoronto.ca.
authors.forename: Xiuling
authors.initials: X
authors.lastname: Qi
authors.affiliation: Schulich Heart Centre, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Room D-406, Toronto, ON, M4N 3M5, Canada. wolffdr@hotmail.com.|University of Toronto, Toronto, Canada. wolffdr@hotmail.com.
authors.forename: Rafael
authors.initials: R
authors.lastname: Wolff
authors.affiliation: Schulich Heart Centre, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Room D-406, Toronto, ON, M4N 3M5, Canada. michelle.rose21@gmail.com.
authors.forename: Michelle
authors.initials: M
authors.lastname: Ladouceur-Wodzak
authors.affiliation: Schulich Heart Centre, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Room D-406, Toronto, ON, M4N 3M5, Canada. toviberk@gmail.com.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Berk
authors.affiliation: Department of Pathology, University Health Network, Toronto, Canada. Jagdish.Butany@uhn.ca.|University of Toronto, Toronto, Canada. Jagdish.Butany@uhn.ca.
authors.forename: Jagdish
authors.initials: J
authors.lastname: Butany
authors.affiliation: Toronto General Research Institute, Toronto, Canada. Mansoor.Husain@uhn.ca.|University of Toronto, Toronto, Canada. Mansoor.Husain@uhn.ca.
authors.forename: Mansoor
authors.initials: M
authors.lastname: Husain
authors.affiliation: Schulich Heart Centre, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Room D-406, Toronto, ON, M4N 3M5, Canada. gawright@sri.utoronto.ca.|Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada. gawright@sri.utoronto.ca.|University of Toronto, Toronto, Canada. gawright@sri.utoronto.ca.
authors.forename: Graham A
authors.initials: GA
authors.lastname: Wright
authors.affiliation: Schulich Heart Centre, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Room D-406, Toronto, ON, M4N 3M5, Canada. bradley.strauss@sunnybrook.ca.|University of Toronto, Toronto, Canada. bradley.strauss@sunnybrook.ca.
authors.forename: Bradley H
authors.initials: BH
authors.lastname: Strauss
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D000818:Animals; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D017023:Coronary Angiography; D003328:Coronary Thrombosis / Q000097:blood / Q000473:pathology* / Q000503:physiopathology; D004195:Disease Models, Animal; D004617:Embolism / Q000097:blood / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D019028:Magnetic Resonance Imaging, Cine; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D009203:Myocardial Infarction / Q000097:blood / Q000473:pathology* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D054318:No-Reflow Phenomenon / Q000097:blood / Q000473:pathology* / Q000503:physiopathology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D013552:Swine; D013997:Time Factors; D019210:Troponin I / Q000097:blood; D020257:Ventricular Remodeling
chemical_list: D015415:Biomarkers; D019210:Troponin I; D051057:Proto-Oncogene Proteins c-akt; D020778:Matrix Metalloproteinase 2