Composition of coronary thrombus in acute myocardial infarction

J Am Coll Cardiol. 2011 Mar 22;57(12):1359-67. doi: 10.1016/j.jacc.2010.09.077.

Abstract

Objectives: 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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood
  • CD40 Ligand / blood
  • Coronary Thrombosis / complications*
  • Coronary Thrombosis / metabolism*
  • Female
  • Humans
  • Male
  • Microscopy, Electron, Scanning
  • Middle Aged
  • Multivariate Analysis
  • Myocardial Infarction / etiology*
  • Plaque, Atherosclerotic / chemistry*
  • Time Factors

Substances

  • Biomarkers
  • CD40 Ligand