Role of Aspirin for Primary Prevention in Persons with Diabetes Mellitus and in the Elderly.

To review the clinical evidence of the effect of aspirin as primary prevention for patients with diabetes mellitus and in healthy elderly. Two trials were performed to study these two patient populations: ASCEND showed that the use of low-dose aspirin in persons with diabetes, who did not have prior cardiovascular disease, led to a lower risk of cardiovascular events than placebo (8.5% vs 9.6%, rate ratio 0.88, 95% CI 0.79-0.97; p = 0.01). However, it showed a similar magnitude of increased risk of major bleeding among the aspirin group compared with placebo (4.1% vs 3.2%, rate ratio 1.29, 95% CI 1.09-1.52; p = 0.003). ASPREE showed that the use of low-dose aspirin in healthy elderly did not prolong disability-free survival (21.5% vs 21.2%, HR 1.01, 95% CI 0.92-1.11; p = 0.79); however, the rate of major hemorrhage was higher in the aspirin group than in the placebo group (3.8% vs 2.8%, HR 1.38, 95% CI 1.18-1.62; p < 0.001). Additionally, further analyses of secondary end points of death, cardiovascular disease, and major hemorrhage were also studied. Higher all-cause mortality was seen among healthy elderly who received aspirin compared with placebo (12.7% vs 11.1%, HR 1.14, 95% CI 1.01-1.29) and was primarily attributed to cancer-related deaths. Similar risk of cardiovascular disease was seen among elderly who received aspirin compared with placebo (10.7% vs 11.3%, HR 0.95, 95% CI 0.83-1.08) and resulted in a significantly higher risk of major hemorrhage (8.6% vs 6.8%, HR 1.38, 95% CI 1.18-1.62; p < 0.001). These studies show that the use of low-dose aspirin as primary prevention in patients with diabetes and in the elderly does not have overall beneficial effect compared with its use in secondary prevention. In patients with diabetes without prior cardiovascular disease, the benefits of aspirin use were counterbalanced by the bleeding risk. Additionally, in healthy elderly, the use of aspirin did not prolong disability-free survival and instead led to a higher rate of major hemorrhage.