The ASPirin in Reducing Events in the Elderly (ASPREE) trial randomized 19,114 healthy, community-dwelling older adults to receive either daily aspirin (100 mg/d) for primary prevention of cardiovascular disease (CVD) or placebo. In a recent secondary analysis of the trial, researchers found that daily aspirin increased risk for major GI bleeding by about 60% overall in older adults. The absolute five-year risk of bleeding was 0.25% (95% CI, 0.16% to 0.37%) for a 70-year-old not taking aspirin and up to 5.03% (95% CI, 2.56% to 8.73%) for an 80-year-old taking aspirin with additional risk factors.
The analysis of the ASPREE trial by Mahady and colleagues shows that, in adults aged ≥70 years, 100 mg of daily aspirin for primary prevention of CVD was associated with a 61% increased risk for clinically important GI bleeding at 5 years, compared with placebo. The absolute risk for GI bleeding increased 2.4-fold between the ages of 70 and 80 years, regardless of whether the participant was receiving aspirin. Population-based research has shown that risk for major bleeding associated with aspirin remains <1% per year until around age 70 years, after which it increases exponentially. The ASPREE trial found that among older adults, aspirin is no better than placebo for preventing CVD or a composite endpoint of death, disability, or dementia.
Aspirin is not recommended for primary prevention of CVD in most adults aged ≥70 years due to the overall lack of efficacy and increased risk for GI bleeding. However, subpopulations of older adults who have a high risk for CV events may show a net benefit from primary prevention with aspirin. A meta-analysis of 10 randomized trials of mostly middle-aged adults with diabetes found that aspirin was associated with a 10% reduction of major adverse CV events (relative risk, 0.90 [95% CI, 0.81 to 0.99]). In a small, open-label trial, patients with chronic kidney disease who were randomly assigned to primary prevention with aspirin (mean age, 67 y) had reduced risk for a composite CV endpoint, compared with usual care, over a mean follow-up of 65 months. More research is needed to assess the role of primary CVD prevention with aspirin in select high-risk populations of older adults.