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Determination of the Procoagulant Activity of Extracellular Vesicle (EV) Using EV-Activated Clotting Time (EV-ACT)
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Determination of the Procoagulant Activity of Extracellular Vesicle (EV) Using EV-Activated Clotting Time (EV-ACT)

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Levels of circulating procoagulant microparticles in nonvalvular atrial fibrillation

Stéphane Ederhy1, Emanuele Di Angelantonio, Ziad Mallat

  • 1Cardiology Department, Saint-Antoine University and Medical School, Université Pierre et Marie Curie, and INSERM U689, Hôpital Lariboisière, Paris, France.

The American Journal of Cardiology
|September 11, 2007
PubMed

Insights

Circulating procoagulant microparticles (MPs) are elevated in atrial fibrillation (AF) patients, indicating a hypercoagulable state. This finding may link AF to increased risk of thrombosis and thromboembolism.

Area of Science:

  • Hematology
  • Cardiology
  • Thrombosis Research

Background:

  • Circulating procoagulant microparticles (MPs) are cell fragments with procoagulant properties.
  • Elevated MP levels are observed in severe thrombotic conditions.
  • Atrial fibrillation (AF) is associated with an increased risk of thromboembolism.

Purpose of the Study:

  • To investigate whether circulating procoagulant MP levels are increased in patients with nonvalvular atrial fibrillation (AF).
  • To explore the potential link between elevated MPs and a hypercoagulable state in AF.

Main Methods:

  • A hospital-based case-control study.
  • Measurement of circulating Annexin V-positive MPs in 45 AF patients (without anticoagulant therapy) and 90 age-matched controls.
  • Subgroup analysis of platelet-derived and endothelial-derived MPs.

Main Results:

  • Annexin V-positive MP levels were significantly higher in AF patients compared to both control groups (p<0.001).
  • Platelet-derived and endothelial-derived MPs were higher in AF patients than in controls without cardiovascular risk factors.
  • AF was identified as a strong predictor of elevated Annexin V-positive MP levels (p<.001).

Conclusions:

  • Circulating procoagulant MPs are elevated in persistent and/or permanent AF.
  • Increased MP levels in AF may signify a hypercoagulable state.
  • This hypercoagulability could contribute to the pathogenesis of atrial thrombosis and thromboembolism in AF patients.

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