Biochemical Aspirin Resistance and Recurrent Lesions in Patients with Acute Ischemic Stroke

Background: The effect of biochemical aspirin resistance (BAR) on ischemic stroke has not been well established. Early recurrent ischemic lesions (ERILs) on diffusion-weighted imaging (DWI) are proposed as potential surrogate markers of clinically recurrent stroke. Methods: We included 117 consecutive patients who (1) were admitted within 24 h of symptom onset; (2) had an ischemic stroke confirmed by DWI; (3) underwent follow-up DWI within seven days after onset, and (4) received aspirin treatment. BAR was measured using the VerifyNow (R) Aspirin Assay. We analyzed the associations between BAR and any ERILs (overall ERILs), and between BAR and ERILs occurring outside the vascular territories of index stroke (distant ERILs). Results: BAR was observed in 16 (13.7%) patients. Overall ERILs were detected in 34 (29.1%), and distant ERILs in 10 (8.5%) patients. Patients with BAR were more likely to develop ERILs, but the association was not significant (OR 2.13; 95% CI 0.72-6.29; p = 0.234). However, BAR was independently related to distant ERILs by logistic regression analysis (OR 6.01; 95% CI 1.29-28.09; p = 0.023). Conclusions: BAR was associated with distant ERILs but not with overall ERILs during the first week after ischemic stroke. Copyright (C) 2010 S. Karger AG, Basel