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Microfluidics in Assessing Platelet Function
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Atrial platelet reactivity in patients with atrial fibrillation

Scott R Willoughby1, Ross L Roberts-Thomson, Han S Lim

  • 1Cardiovascular Research Centre, Department of Cardiology, Royal Adelaide Hospital, Adelaide, Australia.

Heart Rhythm
|March 9, 2010
PubMed

Insights

In atrial fibrillation (AF), platelets show increased activation in the left atrium compared to the right. This chamber-specific platelet reactivity may explain the higher risk of left atrial thrombus formation in AF patients.

Area of Science:

  • Cardiology
  • Hematology
  • Thrombosis Research

Background:

  • Atrial fibrillation (AF) increases thrombus risk in the left atrium, but not the right.
  • Mechanisms for this chamber-specific risk in AF remain unclear.

Purpose of the Study:

  • To investigate potential atrial-specific differences in platelet activation in patients with AF.
  • To determine if platelet reactivity varies between the left and right atria.

Main Methods:

  • Whole-blood flow cytometry analyzed platelet markers (P-selectin, CD51/61, PAC-1) from left atrial, right atrial, and femoral vein samples.
  • Adenosine diphosphate (ADP)-induced platelet aggregation was measured using impedance aggregometry.
  • A reference group controlled for transseptal puncture effects.

Main Results:

  • Left atrial platelet P-selectin levels were significantly higher than in the right atrium.
  • Adenosine diphosphate (ADP)-induced platelet aggregation was significantly greater in the left atrium versus the right atrium and femoral vein.
  • No significant differences in platelet markers or aggregation were observed in the reference group.

Conclusions:

  • Platelet reactivity is elevated in the left atrium compared to the right atrium and peripheral circulation in AF patients.
  • Chamber-specific platelet activation in the left atrium may contribute to thrombus formation.
  • Findings suggest a mechanism for increased left atrial thrombosis in atrial fibrillation.
Abstract

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