title: Aspirin's effect on platelet inhibition in migraineurs.
abstract: 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.
authors.affiliation: The Swedish Heart & Vascular Institute, Swedish Medical Center, Seattle, WA 98122, USA. jill.jesurum@swedish.org
authors.forename: Jill T
authors.initials: JT
authors.lastname: Jesurum
authors.forename: Cindy J
authors.initials: CJ
authors.lastname: Fuller
authors.forename: Natalia
authors.initials: N
authors.lastname: Murinova
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Truva
authors.forename: Sylvia M
authors.initials: SM
authors.lastname: Lucas
mesh_terms: D000328:Adult; D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000097:blood* / Q000150:complications; D009203:Myocardial Infarction / Q000209:etiology; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D012307:Risk Factors; D020521:Stroke / Q000209:etiology
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin