Aspirin Resistance and Ischemic Stroke

Objective : Acetylsalicylic acid (ASA) is the most widely used antiplatelet agent in treating ischemic strokes. ASA resistance varies between the populations, from 5% to 60%. We aimed to determine the prevalence of ASA resistance in our population, its association with demographic characteristics, risk factors, and the occurrence of recurrent ischemic stroke (IS). (IST).

Methods : One hundred consecutive patients with primary or recurrent IS were prospectively included. Strokes were diagnosed with computed tomography (CT) or magnetic resonance imaging (MRI). In all patients a detailed history of cardiovascular risk factors and fasting blood analyzes (blood count, glycemia, HbA1c, degradation products, lipid profile) were taken, and the ASA resistance was examined with the Innovance PFA 200 system. The ASA resistance was examined after a minimum of 1 month of regular use of ASA 100 mg per day.

Results : The prevalence of ASA resistance was 32%. ASA-resistant patients were statistically significantly older (69.9±7.5 vs, 61±1 y., p<0.05), and of male gender (75 vs, 45.6%, p<0.05). Previous cardiovascular diseases were statistically significantly more common in the ASA-resistant patients compared to the ASA-sensitive patients (46.8 vs 26.5%, p<0.05). The presence of recurrent stroke in the ASA-resistant versus ASA-sensitive patients was statistically significant (75% vs. 22.05%, p<0.0001). There was no statistically significant difference in the investigated laboratory parameters and the risk factors between the ASA-resistant and the ASA-sensitive patients.

Conclusion. The prevalence of ASA resistance in our population is high. According to our results, ASA resistance testing should be done in the older male individuals with a previous burden of cardiovascular diseases.