Aspirin resistance is associated with increased stroke severity and infarct volume. (10th May 2016)

• Record Type: Journal Article
• Authors: Oh, Mi Sun; Yu, Kyung-Ho; Lee, Ju-Hun; Jung, San; Kim, Chulho; Jang, Min Uk; Lee, Juneyoung; Lee, Byung-Chul
• Is Part Of: Neurology. Volume 86:Number 19(2016)
• Publication Date: 2016-05-10
• Subjects: Neurology -- Periodicals; Neurology -- Periodicals; Neurologie -- Périodiques; 616.8
• DOI: 10.1212/WNL.0000000000002657
• Languages: English
• ISSNs: 0028-3878

Abstract

Abstract : Objectives: To investigate whether aspirin resistance is associated with initial stroke severity and infarct volume, using diffusion-weighted imaging (DWI) in patients with acute ischemic stroke that occurred while taking aspirin. Methods: We studied a total of 310 patients who were admitted within 48 hours of acute ischemic stroke onset. All patients had been taking aspirin for at least 7 days before stroke onset. Aspirin resistance, defined as high residual platelet reactivity (HRPR) on aspirin treatment, was measured using the VerifyNow assay and defined as an aspirin reaction unit ≥550. Initial stroke severity was assessed using the NIH Stroke Scale (NIHSS) score. Infarct volume was measured using DWI. Results: HRPR occurred in 86 patients (27.7%). The initial NIHSS score (median [interquartile range]) was higher in patients with HRPR than in the non-HRPR group (6 [3–15] vs 3 [1–8], p < 0.001). DWI infarct volumes were also larger in the HRPR group compared to the non-HRPR group (5.4 [0.8–43.2] vs 1.7 [0.4–10.3], p = 0.002). A multivariable median regression analysis showed that HRPR was significantly associated with an increase of 2.1 points on the NIHSS (95% confidence interval 0.8–4.0, p < 0.001) and an increase of 2.3 cm 3 in DWI infarct volume (95% confidence interval 0.4–3.9, p < 0.001). Conclusions: Aspirin resistance is associated with an increased risk of severe stroke and large infarct volume in patients taking aspirin before stroke onset.