Aspirin's effect on platelet inhibition in migraineurs

Headache: The Journal of Head and Face Pain, 04/09/2012

Findings of this exploratory study suggest that migraineurs have a higher prevalence of High on–aspirin platelet reactivity (HAPR) than healthy volunteers or patients with coronary artery disease taking aspirin 325 mg. The clinical implications of HAPR in migraine warrant further exploration due to the risk of stroke and myocardial infarction (MI) and the potential need for antiplatelet therapy in this population.


  • Using a single group, pretest/posttest design, 50 migraineurs without prior history of stroke or MI were prospectively treated for 14 to 21 consecutive days with 325 mg generic enteric–coated aspirin, after undergoing a 14–day aspirin washout.
  • Platelet reactivity was measured after aspirin washout and following aspirin treatment.
  • Subjects were screened for HAPR using the Verify Now Aspirin Assay (Accumetrics, San Diego, CA, USA).
  • HAPR was defined as ≥460 Aspirin Reaction Units (ARU; primary endpoint).


  • 50 subjects, 44 (88%) female, aged (mean ± standard deviation) 43 ± 12 years were enrolled.
  • 12 (24%; 95% CI 12–36%) subjects, all female, had HAPR and were classified as aspirin resistant.
  • Subjects with HAPR had lower baseline hemoglobin levels than those without HAPR (P = .03).
  • Baseline hemoglobin was significantly correlated with final ARU (r = –0.39, P = .005).

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