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Evaluation of clopidogrel resistance in ischemic stroke patients

Takuya Fukuoka1, Daisuke Furuya, Hidetaka Takeda

  • 1Department of Neurology, Saitama International Medical Center, Saitama Medical University, Japan. tfukuoka@saitama-med.ac.jp

Internal Medicine (Tokyo, Japan)
|January 8, 2011
PubMed

Insights

Clopidogrel resistance in ischemic stroke patients varied from 8-18% based on measurement methods. This highlights the importance of assay selection for assessing antiplatelet drug effectiveness.

Area of Science:

  • Cardiovascular Medicine
  • Pharmacology
  • Neurology

Background:

  • Clopidogrel is a potent antiplatelet medication.
  • Clopidogrel resistance, where platelet inhibition is inadequate despite treatment, is a growing concern.
  • Ischemic stroke patients are a key population for evaluating clopidogrel efficacy.

Purpose of the Study:

  • To evaluate the prevalence of clopidogrel resistance in patients with ischemic stroke.
  • To compare different methods for measuring platelet aggregation and clopidogrel resistance.

Main Methods:

  • Seventy-two ischemic stroke patients received clopidogrel 75 mg/day for at least one week.
  • Platelet aggregometry was performed using turbidimetry and a screen filtration pressure method.
  • Resistance criteria were defined based on specific adenosine diphosphate (ADP) concentrations and aggregation rates.

Main Results:

  • Clopidogrel resistance rates ranged from 8.3% to 18.1% using turbidimetry with different ADP concentrations.
  • The screen filtration pressure method indicated an 8.1% rate of clopidogrel resistance.
  • Discrepancies were noted in resistance measurements between the two methods within the same patient.

Conclusions:

  • The prevalence of clopidogrel resistance is highly dependent on the chosen measurement method and resistance definition.
  • The study observed clopidogrel resistance rates between 8% and 18% in ischemic stroke patients.
  • These findings underscore the variability in assessing antiplatelet response and the need for standardized methodologies.
Abstract

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