title: Composition of coronary thrombus in acute myocardial infarction.
abstract: OBJECTIVE
  We sought to analyze the composition of coronary thrombus in vivo in ST-segment elevation myocardial infarction (STEMI) patients.
  
  
  BACKGROUND
  The dynamic process of intracoronary thrombus formation in STEMI patients is poorly understood.
  
  
  METHODS
  Intracoronary thrombi (n = 45) were obtained by thromboaspiration in 288 consecutive STEMI patients presenting for primary percutaneous intervention, and analyzed using high-definition pictures taken with a scanning electron microscope. Plasma biomarkers (TnI, CRPus, IL-6, PAI-1, sCD40 ligand, and TNF-α) and plasma fibrin clot viscoelastic properties were measured simultaneously on peripheral blood.
  
  
  RESULTS
  Thrombi were mainly composed of fibrin (55.9 ± 18%) with platelets (16.8 ± 18%), erythrocytes (11.5 ± 9%), cholesterol crystals (5.2 ± 8.4%), and leukocytes (1.3 ± 2.0%). The median ischemic time was 175 min (interquartile range: 140 to 297). Ischemic time impacted thrombi composition, resulting in a positive correlation with intracoronary thrombus fibrin content, r = 0.38, p = 0.01, and a negative correlation with platelet content, r = -0.34, p = 0.02. Thus, fibrin content increased with ischemic time, ranging from 48.4 ± 21% (<3 h) up to 66.9 ± 9% (>6 h) (p = 0.02), whereas platelet content decreased from 24.9 ± 23% (<3 h) to 9.1 ± 6% (>6 h) (p = 0.07). Soluble CD40 ligand was positively correlated to platelet content in the thrombus (r = 0.40, p = 0.02) and negatively correlated with fibrin content (r = -0.36; p = 0.04). Multivariate analysis indicated that ischemic time was the only predictor of thrombus composition, with a 2-fold increase of fibrin content per ischemic hour (adjusted odds ratio: 2.00 [95% confidence interval: 1.03 to 3.7]; p = 0.01).
  
  
  CONCLUSIONS
  In acute STEMI, platelet and fibrin contents of the occlusive thrombus are highly dependent on ischemia time, which may have a direct impact on the efficacy of drugs or devices used for coronary reperfusion.
authors.affiliation: Institut de Cardiologie, INSERM UMRS937, Pitié-Salpêtrière Hospital (AP-HP), Université Paris 6, Paris, France.
authors.forename: Johanne
authors.initials: J
authors.lastname: Silvain
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Collet
authors.forename: Chandrasekaran
authors.initials: C
authors.lastname: Nagaswami
authors.forename: Farzin
authors.initials: F
authors.lastname: Beygui
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Edmondson
authors.forename: Anne
authors.initials: A
authors.lastname: Bellemain-Appaix
authors.forename: Guillaume
authors.initials: G
authors.lastname: Cayla
authors.forename: Ana
authors.initials: A
authors.lastname: Pena
authors.forename: Delphine
authors.initials: D
authors.lastname: Brugier
authors.forename: Olivier
authors.initials: O
authors.lastname: Barthelemy
authors.forename: Gilles
authors.initials: G
authors.lastname: Montalescot
authors.forename: John W
authors.initials: JW
authors.lastname: Weisel
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D023201:CD40 Ligand / Q000097:blood; D003328:Coronary Thrombosis / Q000150:complications* / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000209:etiology*; D058226:Plaque, Atherosclerotic / Q000737:chemistry*; D013997:Time Factors
chemical_list: D015415:Biomarkers; D023201:CD40 Ligand