The results from the trial, published Sunday in three studies in the New England Journal of Medicine, show that the rate of cardiovascular disease was 10.7 events per 1,000 person-years in the aspirin group and 11.3 events per 1,000 person-years in the placebo group. At the same time, the rate of hemorrhage was 8.6 events per 1,000 person-years in the aspirin group and 6.2 events in the control group.
Prescribing aspirin to healthy people to prevent the onset of heart disease is controversial although it happens.
There is substantial evidence that supports the daily use of aspirin for secondary prevention of heart disease, which means patients are prescribed the drug after they've already experienced a heart attack or stroke.
But that evidence has caused much debate over whether the drug can therefore be used to prevent heart disease before it presents itself.
The line of thinking is "well if it works to prevent a second heart attack or stroke, why wouldn't it prevent the first one?" said Dr. John McNeil, co-principal investigator of the trial and professor in the department of epidemiology and preventive medicine at Monash University in Australia.
Other studies have been conducted that address this question with mix results. In fact, those studies prompted the U.S. Preventive Services Task Force in 2016 to change its recommendations on aspirin use for primary prevention of cardiovascular disease, limiting its use to adults 50 to 59 who have a 10% or greater risk. For adults 60 to 69, the task force recommended the decision should be made on a case-by-case basis. The 2009 task force recommendations applied aspirin use to a broader set of patients.
The latest clinical trial, which was funded in part by the National Institute on Aging, is unique because it looked at a much older population of patients compared to previous studies. The median age of the participants in the trial was 74.
Murray said she hopes the new findings will be considered by the taskforce to add to their recommendations. The U.S. Preventive Services Task Force has been unable to make a recommendation for those 70 and older because there is so little research on the population.
McNeil added it was important to focus on this cohort because aspirin is used by healthy, older people in the hopes that it will keep them well, with some even taking it without a prescription from their physician.
Taking this into account, the trial also explored the effect of aspirin on survival rates without disability. The patients who took aspirin didn't report differences in dementia or physical disability compared to the control group.
McNeil said these findings are significant considering the size of the retirement population.
"The number of elderly people is increasing rapidly and it's becoming important to keep people active and out of institution as long as possible not only for their own self but for the sake of the economy," he said.
