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A daily aspirin may be beneficial for people who have had a heart attack, researchers say. Maria Korneeva/Getty Images
  • Researchers say people who had a previous cardiovascular event should take a baby aspirin every day after discussing it with their doctor.
  • They say the small risk from taking baby aspirin is outweighed by the benefits it provides in such cases.
  • Daily aspirin is no longer recommended for people who have not had a previous cardiovascular event.

People who have had a heart attack and do not take a daily aspirin have an elevated likelihood of recurring heart attack, stroke, or death compared to those who consistently take aspirin after the event.

That’s according to research presented on August 22 at the ESC Congress 2023.

The findings have not been published yet in a peer-reviewed journal. The new study from Denmark examined the risk associated with discontinuing long-term aspirin compared to continued use after a heart attack.

The researchers looked at data from the Danish nationwide health registry, which included 40,114 people, aged 40 and over, who had a first heart attack between 2004 and 2017. The participants were treated with a coronary stent and took aspirin during the first year after their heart attack. The researchers excluded people on anticoagulants and those who had a stroke or second heart attack within the first year.

In Denmark, when people pick up an aspirin prescription, the number of tablets and the date they picked it up are recorded in registries, providing robust data for the study.

The researchers evaluated aspirin use for the study participants at two, four, six, and eight years after the heart attack. Aspirin compliance declined at each checkpoint:

  • two years after the event, 90% continued to use aspirin
  • at four years, 84% were in compliance
  • at six years, 82% still used aspirin
  • at eight years, compliance was at 81%

In the study, researchers reported that people who took aspirin as prescribed were less likely to experience another event than non-adherence for all four-time points.

  • At the two-year follow-up, those who had stopped taking aspirin had an 29% higher likelihood of a recurrent heart attack, stroke, or death.
  • At the four-year follow-up, the participants no longer taking aspirin were 40% more likely to have a second event.
  • At the six-year follow-up, the participants who no longer took daily aspirin had a 31% higher likelihood of a second event.
  • At the eight-year follow-up, there was a 20% higher likelihood of a recurrent heart attack, stroke, or death for those no longer taking aspirin.

“There has been a lot of discussion and a lot of back and forth on the pros and cons of taking aspirin for heart conditions,” said Dr. Lawrence Phillips, the director of outpatient clinical cardiology at NYU Langone Heart and an associate professor in the Department of Medicine in the Leon H. Charney Division of Cardiology at NYU Grossman School of Medicine.

“It is important to remember that this study does not address the general population. It is only talking about people who have had at least one prior cardiovascular event,” Phillips, who was not involved in the study, told Medical News Today.

Aspirin has been used for more than 100 years for minor pain and fever. While it is safe when used as directed, side effects include stomach upset and bleeding.

“Aspirin is often portrayed as a safe treatment for heart conditions. However, this is true only for people who have had a previous cardiovascular event,” said Dr. Michael Broukhim, an interventional cardiologist at Providence Saint John’s Health Center in California who was not involved in the study.

“[Asprin can be harmful when taken for no reason, including people who have not had a previous cardiovascular event. It should only be taken after a discussion with your doctor,” he told MNT.

Dr. Sameer Amin, the chief medical officer at LA Care Health Plan in California, not involved in the study, noted to MNT:

“The primary risk of low-dose aspirin is a small chance of bleeding. In patients who have had a previous heart attack or stroke, the risk of another event is high and the small chance of bleeding from a baby aspirin is far outweighed by a significantly lower risk of having another heart attack or stroke. In these cases, it is clear that people should take aspirin. For a person who has never had a heart attack or stroke and is otherwise healthy, the risk of a first event is lower. In those instances, the benefit may be low and it may not make sense to take on that low risk of bleeding.”

Last year, the U.S. Preventive Task Force concluded that daily aspirin use has little or no benefit for most people who are not at high risk of a cardiovascular event.

Part of the confusion about when aspirin is beneficial is in understanding primary and secondary prevention.

“When we think of prevention, we divide people into primary and secondary prevention,” said Dr. Yu-Ming Ni, a cardiologist and lipidologist at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in California who was not involved in the study.

“Primary prevention is to prevent a first heart event; secondary prevention works to prevent a subsequent one,” Ni explained to MNT. “Aspirin therapy is a secondary prevention method. We should not prescribe aspirin if someone has not had a heart attack unless there are extenuating medical circumstances.”

“I agree with the study’s notion of how important aspirin is for people who have had a heart attack. We often assume that something is true based on our observation. This study gives us a clear answer. We now know that aspirin significantly reduces that risk for people at elevated risk of having subsequent heart events.”

— Dr. Yu-Ming Ni, cardiologist

Convincing people to take an aspirin every day isn’t always an easy task.

Another study published on August 22 by researchers at Washington University School of Medicine in St. Louis and the University of Michigan reported that fewer than half of people worldwide who have had a heart attack or stroke take a daily aspirin.

The researchers examined surveys completed by 124,505 people, with 10,589 self-reporting a history of cardiovascular disease.

They reported that in low-income countries, only about 16% of those who had experienced a heart attack or stroke took aspirin to prevent a second or subsequent one. In lower middle-income countries, the rate rose to about 24%.

Upper middle-income countries saw this number increase to 51%. In high-income countries, 65% of people with previous cardiovascular events took aspirin.

The researchers indicated they can’t explain why aspirin is underused, but they hypothesized several reasons, including:

  • varying accessibility to healthcare
  • inconsistent messaging surrounding the use of aspirin
  • aspirin is not always available over the counter (some countries require a prescription)

There are a myriad of factors that could influence your doctor’s recommendations on whether you should or shouldn’t take aspirin, Broukhim explained.

For example, if you are taking Eliquis, your doctor could tell you to continue taking that and not take aspirin.

“The take-home message, as I see it, is that people should not make medical decisions independently,” Phillips said. “Do not change anything without first talking to your doctor. Patient care is individualized, so what is good for someone else may not be good for you.”

Sometimes, though, it can seem like some doctors recommend daily aspirin and others discourage it.

“I do not think that is the way to look at the issue,” Dr. Dennis Finkielstein, the associate chair of cardiology at Northwell Lenox Hill Hospital in New York, not involved in the study, told MNT.

“All doctors will consider what is best for the individual they are treating. Therefore, some patients with elevated bleeding risks will be advised to discontinue aspirin if their cardiovascular disease is deemed stable and they are otherwise medically optimized. Other patients with low bleeding risk will be advised to continue aspirin therapy long-term.”

— Dr. Dennis Finkielstein, cardiologist