Aspirin: Stroke preventer or silent killer? Answer: It depends

Talk to your doctor about whether this large, long-term study applies to you

Aspirin stroke preventer or silent killer

It has long been believed that a daily dose of aspirin could help protect against strokes and heart attacks but a new five-year study suggests the risk of brain bleeds may outweigh any benefits in patients without existing cardiovascular problems.

The study was published in JAMA Network Open and is causing a stir in the medical community. It found that aspirin's well-known proclivity for reducing blood clotting may be setting the stage for disastrous brain bleeds.

Talk to your doctor before making any changes in your current medication. The findings in this study, as in most others, don't necessarily apply to everyone. Only your physician can give you a definitive answer.

Researchers followed a group of 19,000 healthy older Australians and Americans for five years. Their findings:

  • Prescription of daily low-dose aspirin failed to diminish the risk of first-time ischemic stroke (the type cause by a blood clot).
  • The individuals who took aspirin were exposed to an elevated risk of hemorrhagic stroke or intracranial bleeding by 38%.

"These findings suggest that low-dose aspirin may have no role for the primary prevention of stroke and that caution should be taken with use of aspirin in older persons prone to head trauma (eg, from falls)," the researchers said.

The findings are the latest blow to the long-held theory that low-dose aspirin was safe for most people, a belief that has been steadily eroding recently.

Last March, the American College of Cardiology published new guidelines recommending against routinely giving aspirin to older adults who don't have a history of heart disease. “The thinking on this has dramatically changed just in the last year,” said Amit Khera, M.D., director of the Preventive Cardiology program at the UT Southwestern Medical Center., a coauthor of the guidelines, in an AARP Bulletin report.

Findings apply only to healthy individuals

It's not the first study to identify the risk but it is getting a lot of attention because of the large sample size and the five-year time frame over which the participants were watched in the double-blind placebo-controlled trial.

“This study adds to the growing body of evidence that the routine use of aspirin to prevent first-time cardiovascular events in the general adult population is of limited benefit and may cause harm due to excess bleeding, particularly in older adults," said Dr. Arun Manmadhan, assistant professor of medicine at Columbia University in a Medical News Today article.

"This study aligns with recent U.S. Preventive Services Task Force recommendations that advise against the routine use of aspirin to prevent cardiovascular disease in adults over the age of 60,” Manmadhan said.

Listen to your doctor

The essential point here is that the risk of brain bleeds increased in individuals who did not have a prior medical history of heart attack or stroke. Patients who do have vascular health issues may benefit from a daily low-dose aspirin and should only make decisions after consulting with their physician.

Researchers said the study, while valuable, has to be read carefully.

Dr. Maria Parekh, a stroke researcher at UTHealth Houston noted the trial looked at aspirin as "primary stroke prevention" – to ward off first-time events –  in healthy older adults. That means it weeded out people who were most likely to benefit from low-dose aspirin and who would therefore be most likely to benefit from a daily aspirin.

Watch for symptoms

With or without daily aspirin doses, brain bleeds are more likely to afflict older people, especially after a fall or head injury. Symptoms include a worsening headache, vomiting, dizziness, confusion, unequal pupils and slurred speech.

If you have recognize these symptoms, you should immediately contact your doctor or head to the nearest emergency room. Brain bleeds can cause serious long-term damage and must be treated immediately.