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Updated: Jul 14, 2026
Microfluidics in Assessing Platelet Function
Published on: November 8, 2024
Abnormal PFA-100 closure time is associated with increased platelet aggregation in patients presenting with chest
Andrew D Atiemo1, Ladina S Ng'Alla, Dhananjay Vaidya
1Department of Medicine, Johns Hopkins Medical Institute, Baltimore, MD, USA.
Insights
Aspirin non-responsiveness in chest pain patients, identified by PFA-100, indicates increased platelet activation. However, this aspirin resistance did not lead to more clinical events during hospitalization.
Area of Science:
- Cardiology
- Hematology
- Clinical Medicine
Background:
- Antiplatelet therapy, including aspirin, is crucial for preventing cardiovascular events like myocardial infarction and stroke.
- A significant number of patients exhibit reduced responsiveness to aspirin, which is linked to an increased risk of ischemic events.
- Assessing platelet function is vital for understanding treatment efficacy and patient outcomes.
Purpose of the Study:
- To evaluate platelet function in patients presenting with chest pain using the PFA-100 point-of-care assay.
- To correlate PFA-100 results with traditional platelet aggregometry.
- To determine if aspirin non-responsiveness is associated with increased clinical sequelae in these patients.
Main Methods:
- Platelet function was assessed in 94 chest pain patients using PFA-100, flow cytometry, and optical aggregometry.
- All participants were receiving daily aspirin (81-325 mg).
- Clinical events during the index hospitalization were recorded.
Main Results:
- Half of the patients (50%) were classified as aspirin non-responders based on PFA-100 results (closure time ≤ 193).
- Aspirin non-responders showed significantly higher platelet aggregation to ADP and epinephrine, and increased PAC-1 expression compared to responders.
- No significant difference in clinical events was observed between aspirin non-responders and responders during the index hospitalization.
Conclusions:
- Abnormal PFA-100 closure times in chest pain patients reflect heightened platelet aggregation and activation.
- Aspirin non-responsiveness, as indicated by PFA-100, did not correlate with an increased incidence of clinical events during the index hospitalization.
Background:
Antiplatelet therapy has been proven to be effective for both primary and secondary prevention of myocardial infarction, stroke, and cardiovascular death. However, a significant proportion of patients treated with aspirin experience ischemic events. A number of prospective studies have demonstrated that decreased responsiveness to antiplatelet therapy as measured by various methods, is strongly associated with an increase in clinical events. Our objective was to characterize platelet function in patients presenting with chest pain using a point-of-care assay, PFA-100 and correlating results to traditional platelet aggregometry to determine if patients with aspirin non-responsiveness have increased clinical sequelae.
Methods:
Platelet function was assessed using PFA-100, flow cytometry, and optical aggregometry in 94 patients presenting to the emergency department with chest pain. All patients were on aspirin 81-325 mg daily. Clinical events occurring during the index hospitalization were documented.
Results:
Forty-seven patients (50%) were defined as aspirin non-responders by PFA-100 (collagen-epinephrine closure time
Conclusion:
Patients presenting with chest pain who have abnormal PFA-100 closure times have increased platelet aggregation and activation however this aspirin non-responsiveness does not correlate with increased clinical events in the index hospitalization.
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