Prophylactic aspirin and the elderly population.

A wide array of clinical trials over the past two decades has established that aspirin is indicated to prevent myocardial infarction in patients with clinically evident coronary artery disease, and to prevent stroke in patients with a history of stroke or TIAs. The most likely mechanism by which aspirin decreases the incidence of myocardial infarction is by preventing coronary thrombosis in patients with obstructive coronary artery disease. This protective effect of aspirin should occur in patients with both clinically silent and clinically evident coronary artery disease. For this reason, it has been recommended that patients with risk factors for coronary artery disease also should be treated with prophylactic aspirin. Advanced age is one of the strongest risk factors for coronary artery disease, and the mortality of myocardial infarction rises steeply with increased age. A prospective randomized study of US male physicians without a history of myocardial infarction demonstrated a 44% reduction in myocardial infarction in those treated with 325 mg aspirin every other day. The treatment effect occurred only in those aged 50 or older. A prospective study of US nurses aged 34 to 65, without a history of diagnosed coronary artery disease, demonstrated a 32% decrease in those who took one to six aspirin per week. Again, the treatment effect was seen only in those aged 50 or older. Given these findings, the authors believe that prophylactic aspirin is indicated in men and women aged 50 or older who do not have contraindications to its use. The authors recommend a dose of 325 mg of aspirin every other day, a dose with minimal side effects.