Low-dose aspirin does not prevent onset of cardiovascular disease in older adults (ASPREE)

Reference

McNeil JJ, Wolfe R, Woods RL, et al, for the ASPREE Investigator Group. Effect of aspirin on cardiovascular events and bleeding in the healthy elderly. N Engl J Med 2018;379(16):1509-1518.

Synopsis

The Aspirin in Reducing Events in the Elderly (ASPREE) trial randomized 19,114 community-dwelling adults to receive either 100 mg of enteric-coated aspirin or placebo. The study was conducted in the United States and Australia, with patients recruited between 2010 and 2014. Participants were 70 years or older (65 years or older if black or Hispanic in the United States, because of their shorter average lifespan), had no serious comorbidity that would be expected to limit their life expectancy to less than 5 years, and no known cardiovascular (CV) or cerebrovascular disease, dementia, high bleeding risk, or contraindication to aspirin. The study included a 1-month placebo run-in period to ensure at least 80% adherence to the study medication. During the run-in period, 4049 patients were excluded, 61% because they failed adherence. Included patients were contacted every 3 months to further encourage adherence and to gather interim data. Outcomes were adjudicated by a committee masked to treatment assignment. The median age of participants was 74 years, 56% were women, and 8.7% were non-white. Most of the patients were recruited in Australia (87%), 74% had hypertension, 65% had hyperlipidemia, and only 11% had diabetes. Participants were followed up for a median of 4.8 years, and only 2.2% withdrew or were lost to follow-up. A separate report found no significant reduction in the composite of death, dementia, and disability. The current report looks at the composite outcome of fatal coronary heart disease, nonfatal myocardial infarction, stroke, and hospitalization for heart failure. This is a broad composite, so it is important to look at individual components of the outcome. In this case, there was no difference between groups regarding the composite or any of the individual components. Major hemorrhage was more common in the aspirin group (8.6 vs 6.2 events per 1000 person-years; hazard ratio 1.38; 95% CI 1.18 - 1.62; number needed to treat to harm = 417 per year).