Aspirin resistance: biological and clinical implications

Cardiovascular events are the leading causes of mortality and morbidity in the United States. This development has prompted the rise of aspirin therapy in the prevention of atherothrombotic events. However, not all patients benefit to the same extent from aspirin therapy and many continue experiencing atherothrombotic complications. Researchers have labeled this phenomenon aspirin resistance, and despite drawing much attention from both researchers and lay people the cause remains unknown. Much needs to be clarified and standardized regarding the phenomenon of aspirin resistance, including the prevalence, definition, appropriate measurement methods, mechanisms, and, most important, linking low response to aspirin with worsened clinical outcomes.