Changes in platelet function independent of pharmacotherapy following coronary intervention in non-ST-elevation myocardial infarction patients

Atherosclerosis. 2015 Nov;243(1):320-7. doi: 10.1016/j.atherosclerosis.2015.09.024. Epub 2015 Sep 21.


Background: High on treatment platelet reactivity (HTPR) is common in patients receiving clopidogrel following an acute coronary syndrome (ACS); it's also associated with increased morbidity and mortality. More potent and predictable antiplatelet drugs have addressed this issue at the expense of increased bleeding. Identification of HTPR and the targeted use of more potent antiplatelet drugs has, so far, broadly failed. We investigate this approach in terms of the timing of platelet function testing and how this can impact on the ability of these bedside tests to predict HTPR around the time of coronary intervention.

Methods: High risk ACS patients treated with 5 days of clopidogrel had platelet function assessed using the multiple electrode aggregometry system (MEA) pre, post and 24 h following percutaneous coronary intervention (PCI). Simultaneous detailed analysis of platelet status was undertaken with quantification of platelet bound and soluble p-selectin and mass spectrometry quantification of the eicosanoid 12-HETE.

Results: As assessed by MEA 40.5% of patients had HTPR pre-PCI; mean aggregation units (AU) in response to ADP were 499.1 ± 46.3 pre-PCI, 407.6 ± 37.7 post-PCI and 269.1 ± 24.6 AU 24 h post-PCI (pre to post PCI p > 0.05, pre to 24 h post-PCI p = 0.0002). This highly significant drop in platelet reactivity was contrasted with on-going expression of platelet bound p-selectin, increased soluble p-selectin and rising 12-HETE concentrations.

Conclusions: This study outlines significant changes in ex-vivo platelet aggregation that occur within 24 h of PCI in high risk NSTEMI patients using bedside PFT. Whilst there were no changes in antiplatelet therapy during the study period its clear that timing is crucial when assessing high on treatment residual platelet activity.

Keywords: Acute coronary syndrome; Clopidogrel; Platelet function testing; Residual platelet reactivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / chemistry
  • Acute Coronary Syndrome / blood*
  • Acute Coronary Syndrome / drug therapy*
  • Adenosine Diphosphate / chemistry
  • Aged
  • Blood Platelets / cytology*
  • Chromatography, Liquid
  • Clopidogrel
  • Electrodes
  • Female
  • Flow Cytometry
  • Humans
  • Luminescence
  • Male
  • Mass Spectrometry
  • Middle Aged
  • Myocardial Infarction / therapy*
  • P-Selectin / metabolism
  • Percutaneous Coronary Intervention*
  • Platelet Aggregation
  • Platelet Aggregation Inhibitors / chemistry
  • Platelet Function Tests
  • Prospective Studies
  • Tandem Mass Spectrometry
  • Ticlopidine / administration & dosage
  • Ticlopidine / analogs & derivatives*


  • P-Selectin
  • Platelet Aggregation Inhibitors
  • SELP protein, human
  • 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid
  • Adenosine Diphosphate
  • Clopidogrel
  • Ticlopidine