Aspirin resistance may be identified by miR-92a in plasma combined with platelet distribution width

Objective: Aspirin is a widely used drug for prevention of thrombotic events in cardiovascular patients, but approximately 25% of patients experience insufficient platelet inhibition due to aspirin, and remain in risk of cardiovascular events. This study aimed to investigate the value of circulating miR-92a and platelet size as biomarkers of the individual response to aspirin therapy. Methods: Blood samples were collected from 50 healthy blood donors without antithrombotic medication and 50 patients with intermittent claudication on daily aspirin therapy. Based on results from the arachidonic acid stimulated aggregation test on Multiplate (R) analyzer (ASPItest), patients were defined as aspirin resistant (n = 10) or aspirin responders (n = 40). Plasma levels of miR-92a were evaluated by RT-qPCR analysis and platelet distribution width (PDW) was used to assess platelet size variability. Receiver operating characteristic curves for miR-92a levels and PDW were used to set cut-off values for discrimination between aspirin responding and aspirin resistant patients. Results: When defining aspirin resistance as an ASPItest >= 30 U, the optimal cut-off values for discrimination of aspirin responders and aspirin resistant patients were found to be PDW > 11.8 fL and a relative-expression level of miR-92a > 4.5. Using these cut-off values we could define a PDW/miR-92a-score with a specificity of 97.5% and a sensitivity of 80.0% in relation to detect aspirin resistance. The corresponding positive and negative predictive values were found to be 88.9% and 95.1%, respectively. Conclusion: Aspirin resistance can potentially be identified by miR-92a levels in plasma combined with PDW. (C) 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.