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Microfluidics in Assessing Platelet Function
Published on: November 8, 2024
Expression of platelet surface receptors and early changes in platelet function in patients with STEMI treated with
Anna Konopka1, Justyna Spychalska, Dariusz Sitkiewicz
1Institute of Cardiology and Institute of Haematology and Blood Transfusion in Warsaw, Warsaw, Poland. akonopka@ptkardio.pl
Insights
Adding abciximab to clopidogrel therapy in ST-segment elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary intervention (PCI) significantly increases platelet closure time. Clopidogrel alone did not alter platelet function but reduced platelet activation.
Area of Science:
- Cardiology
- Hematology
- Pharmacology
Background:
- Platelets are key in acute coronary syndromes (ACS) pathogenesis.
- Effective antiplatelet therapy is vital for successful percutaneous coronary intervention (PCI) in ACS patients.
Purpose of the Study:
- To evaluate the impact of clopidogrel, with or without abciximab, on platelet surface receptors and function.
- To assess these effects in ST-segment elevation myocardial infarction (STEMI) patients undergoing PCI.
Main Methods:
- Thirty STEMI patients received aspirin and clopidogrel loading doses.
- Group A (n=21) received additional abciximab; Group B (n=9) received only clopidogrel.
- Platelet aggregation (closure time [CT]) and surface antigens (CD41a, CD62P) were measured pre- and post-therapy.
Main Results:
- Group A showed significantly increased CT with ADP and epinephrine post-therapy.
- Group B had no significant change in CT.
- CD41a (GP IIb/IIIa) increased significantly in Group A; CD62P expression showed no significant change in either group.
Conclusions:
- Abciximab therapy increases GP IIb/IIIa receptors, with platelets remaining unactivated for up to 12 hours post-cessation.
- Clopidogrel monotherapy in STEMI patients undergoing PCI reduces active platelets but does not impact CT.
Background:
Platelets play a crucial role in the pathogenesis of acute coronary syndromes (ACS). The efficacy of antiplatelet treatment is pivotal in the success of percutaneous coronary intervention (PCI) performed in patients with ACS.
Objective:
The aim of the study was to investigate the effects of clopidogrel with or without abciximab on the expression of platelet surface receptors and platelet function in patients with ST-segment elevation myocardial infarction (STEMI) undergoing PCI.
Materials And Methods:
Thirty patients with STEMI were included in the study. During acute primary coronary intervention, patients received aspirin (acetylsalicylic acid) and clopidogrel in a loading dose of 300mg. Clopidogrel was the only antiplatelet therapy used by nine patients (group B). Twenty-one patients (group A) received additional abciximab. Blood samples were collected and analyzed twice: before and up to 22 hours after administration of antiplatelet therapy. The platelet aggregation was established as primary platelet-related hemostasis (closure time [CT] assessed using the PFA100 system). The absolute number of platelet surface antigens as CD41a, CD42a, CD42b, CD61, and CD62P were determined by flow cytometry analysis.
Results:
The study revealed a statistically significant increase in CT induced by adenosine diphosphate and adrenaline (epinephrine) +130 seconds (p < 0.0001) and +94 seconds (p < 0.0001), respectively, in group A patients post-therapy. While in group B the parameters of CT did not change after treatment. In addition, the absolute number of CD41a antigens (glycoprotein [GP] IIb/IIIa) increased significantly after treatment in group A. No significant changes were observed after treatment in the expression of CD62P (P-selectin) antigens in either treatment group. There was a significant reduction in the percentage of CD62P-positive platelets in group B after antiplatelet therapy.
Conclusions:
The absolute number of GP IIb/IIIa receptors increases and platelets are not activated up to 12 hours after cessation of abciximab therapy. Treatment of STEMI patients undergoing PCI with a loading dose of clopidogrel reduces the percentage of active platelets but does not influence the CT.
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