Objective: To assess the effect of aspirin on platelet reactivity in migraineurs.
Background: Migraineurs, particularly women with aura and high monthly migraine frequency, are at risk for ischemic stroke and myocardial infarction (MI). High on-aspirin platelet reactivity (HAPR), or aspirin resistance, has been reported in females and patients with coronary artery disease, and is associated with adverse outcomes.
Methods: 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 VerifyNow™ Aspirin Assay (Accumetrics, San Diego, CA, USA). HAPR was defined as ≥ 460 Aspirin Reaction Units (ARU; primary endpoint).
Results: Fifty subjects, 44 (88%) female, aged (mean ± standard deviation) 43 ± 12 years were enrolled. Twelve (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).
Conclusions: Findings of this exploratory study suggest that migraineurs have a higher prevalence of 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 MI and the potential need for antiplatelet therapy in this population.
© 2012 American Headache Society.