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® 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 © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]