The Aspirin Resistance Controversy

In acute coronary syndromes, rupture or fissuring of the atherosclerotic plaque exposes the subendothelium and lipid core, which leads to platelet adhesion and activation. Although the most commonly used inhibitor of this process is aspirin, information about its limitations has grown over the past decade. Because the absolute risk of recurrent vascular events among patients treated with aspirin remains relatively high (8% to 18% after 2 years),1 a concept known as “aspirin resistance” has flourished. Aspirin resistance has been defined both as a clinical entity (thrombotic event while taking aspirin) and by a myriad of altered biomarkers and enhanced platelet function testing. Although many embrace this concept, others believe that aspirin resistance may reflect treatment failure rather than “resistance” to aspirin.2Article p 2888 Aspirin-related compounds are among the oldest known medicinal substances, with stone tablets documenting the use of willow leaf (a source of salicylic acid) dating back to the Sumerian period.3 Controversy surrounding the use of aspirin can be traced back to the Greek empire, when Hippocrates was a proponent of willow bark for pain, whereas Dioscorides preferred coriander.4 We will never know whether Dioscorides was merely resistant to the beneficial properties of aspirin because thousands of years later we are still trying to understand and define the individual variability seen with its use.The antithrombotic properties of aspirin were first reported in the Mississippi Valley Medical Journal in 1953, and, in the half century since, the benefits of aspirin’s platelet inhibitory properties have been documented in thousands of patients. Clinical trials have demonstrated that aspirin is effective for both primary and secondary prevention of myocardial infarction, stroke, and cardiovascular death, as well as in the acute treatment of unstable coronary disease and stroke.5,6 However, the potential impact of aspirin resistance is great, …