Screening for Aspirin Responsiveness After Transient Ischemic Attack and Stroke

Publisher Website
Google Scholar
Abstract
Background and Purpose— Recent studies suggest that patients who do not respond to aspirin (ASA) therapy may be at increased risk of ischemic vascular events. The availability of simple to use point-of-care (POC) platelet function tests now potentially allows aspirin nonresponsiveness to be identified in routine clinical practice. However, there are very few data on whether the different tests produce consistent results. We therefore compared 2 POC tests (PFA-100 device and the Ultegra-RPFA [RPFA]) with conventional light transmission aggregometry (LTA). Methods— Platelet function was assessed by all 3 tests in 100 patients receiving low-dose ASA therapy after transient ischemic attack (TIA) or ischemic stroke. Results— The incidence of ASA nonresponsiveness was 17% by the RPFA and 22% by the PFA-100, compared with only 5% by LTA (ie, as defined with both arachidonic acid and ADP). Agreement between the RPFA and the PFA-100 and arachidonic acid induced LTA was poor (κ=0.16, 95% CI, −0.08 to 0.39, P=0.11; ...