Why are some individuals resistant to the cardioprotective effects of aspirin? Could it be thromboxane A2?

It has been slightly more than 100 years since the synthesis, development, and commercialization of acetylsalicylic acid, the most widely consumed drug in the world. It is estimated that 35 000 kg are consumed daily in the United States and 6000 kg in the UK.1 Who would have ever thought that this widely consumed drug would achieve significant uses other than as an analgesic, antipyretic, and anti-inflammatory. The first report of a possible antithrombotic effect of aspirin appeared in 1953 in the Mississippi Valley Medical Journal.2 Dr Craven noticed that the patients who took Aspergum had a tendency to bleed more easily. He concluded that aspirin must be thinning the blood and because thrombosis of the coronary arteries led to myocardial infarction, if his patients took aspirin, they might be less prone to experiencing a myocardial infarction.