Despite risks, aspirin use remains high among older adults

New research shows that, in spite of recommendations discouraging use of aspirin in primary prevention of cardiovascular disease among older adults, nearly a third of adults 60 years and older are still using it for this very purpose.

The study, published on Monday in Annals of Internal Medicine, found that 18.5 million adults 60 and older without cardiovascular disease reported using preventative aspirin in 2021. Of those, 3.3 million were using the pills without medical advice.

Daily aspirin was long recommended by physicians to reduce the chance of a heart attack or stroke. But today, clinicians understand that the risk of taking aspirin for adults 60 and older outweighs the benefits of preventing a first heart attack or stroke — in particular, the risk of bleeding, which increases with age.

“This bleeding could be gastrointestinal bleeding or it could be a more feared intracranial or brain bleeding,” said Mohak Gupta, a resident physician at the Cleveland Clinic and study author. “Aspirin enhances that tendency to bleed more so in adults who are 60 years of age.”

That understanding came to the forefront in 2018 as a result of three clinical trials — Ascend, Arrive, and Aspree, which elucidated the benefits and harms of aspirin beyond earlier studies of the drug conducted in the 1990s. Preventative treatment of cardiovascular disease has improved since then, so aspirin use today has less of an impact on risk. Additionally, older adults experience more bleeding than was previously seen with aspirin usage.

Gupta added that the “risk-benefit balance” applies only to primary prevention, or the first event of a cardiovascular event, not to secondary prevention, which is aimed at preventing a future, repeated event. The study sampled data from more than 180,000 participants who took the National Health Interview Survey, collecting data on both primary and secondary prevention in adults aged 40 and older in order to extrapolate trends in aspirin use in adults.

The 2018 findings informed changes in guidelines from the American College of Cardiology and American Heart Association in 2019, suggesting adults 70 and older, or patients of any age with increased bleeding risk, should not take aspirin on a routine basis for primary prevention. And in 2022, the U.S. Preventive Services Task Force released its updated recommendations for primary prevention aspirin use, saying that adults aged 60 and older should not “initiate aspirin for the primary prevention of CVD.”

By tracking statin use between 2012 and 2021, Gupta and his colleagues at Creighton University and Houston Methodist saw that aspirin usage decreased significantly after 2018. “More physicians recommended stopping it after 2018,” Gupta said. But its use among 18.5 million older adults today is still high enough to warrant concern, he said. “That’s a lot of people.”

“I would say not all of this use is inappropriate or risky,” said Gupta. But “a large part of it is likely inappropriate, and mainly a net harm for older adults.”

John Wong, vice chair of the USPSTF, emphasized increased physician-patient conversations in deciding how to best prevent cardiovascular disease. “There are things at the individual level our population evidence-based recommendations don’t take into account,” Wong said.

If a patient and their physician decide that daily aspirin is too risky, they can still plan to manage obesity, stop smoking, and regularly screen for high blood pressure and metabolic disease, said Wong. “Those are all evidence-based, proven methods to prevent that first heart attack or first stroke.”