Is There a Relationship Between Aspirin Responsiveness and Clinical Aspects of Ischemic Stroke?

Background. The issue of aspirin responsiveness in ischemic stroke patients is still unresolved. Objectives. The aim of the study was to determine whether aspirin responsiveness is related to the clinical status of stroke. Material and Methods. Platelet response to acetylsalicylic acid (ASA) was assessed in 64 patients (41 men, mean age: 57.9 +/- 10.4 years) with ischemic stroke or transient ischemic attack receiving the routine dose of 150 mg of ASA daily. Platelet reactivity was assessed using a platelet function analyzer (PFA-100) with collagen/epinephrine cartridges and by whole-blood platelet aggregometry with 0.5 mM arachidonic acid on the first day of acute stroke and after 10 days of ASA intake. Results. Of the 64 patients, 23 (36%) were ASA unresponsive as assessed by the platelet reactivity tests. Based on the Rankin Scale (of 1-5), significantly worse neurological status was observed in the group of grade-3 ASA-Unresponsive compared with grade-2 ASA-responsive patients 10 days after stroke Occurrence (p = 0.02). In all the ASA-unresponsive patients, clinical worsening and/or Computed tomography signs of progression before modification of the antiplatelet and/or antithrombotic treatment were observed. Conclusions. These findings Suggest that assessment of ASA response might be a predictive factor in stroke prognosis and therapy (Adv Clin Exp Med 2009, 18, 5, 473-479).