Daily Low-Dose Aspirin for Heart Attack Prevention: What the Latest Guidelines Mean for You

Aspirin has long been a trusted tool for heart attack prevention because it thins the blood and reduces the risk of blood clots. When taken in smaller amounts — known as low-dose aspirin — it can help prevent clots from forming and blocking blood flow to the heart or brain, lowering the risk of heart attack or stroke.

However, daily aspirin use comes with risks. That's why the U.S. Preventive Services Task Force (USPSTF) updated its guidelines, especially for older adults. So, who should take low-dose aspirin, and what do these changes mean for you?

Dr. Joshua Septimus, a primary care physician at Houston Methodist, explains what to know about the latest recommendations, when aspirin is still appropriate and how any changes to your aspirin use should always be guided by your doctor.

Understanding the latest guidelines

In 2022, the USPSTF updated its recommendations, advising against starting daily low-dose aspirin in adults aged 60 or older for the prevention of heart disease and its life-threatening complications.

"Primary prevention means you're at risk for heart disease and preventive steps are needed to reduce this risk, but there's no evidence that your arteries are actually diseased and you haven't yet had a heart attack or stroke," explains Dr. Septimus.

The guidelines also state that for adults aged 40 to 59 with a 10% or higher risk of developing cardiovascular disease in the next 10 years, the choice to start taking daily aspirin should be individualized. Experts say the potential benefits for this group are small, with people who have a low risk of bleeding (no history of gastrointestinal ulcers and not taking medications that increase the risk of bleeding, for example) being the most likely to benefit.

Here's a quick summary of the recommendations:

• Aspirin should be initiated selectively, based on individual decision-making, rather than routinely for all persons in the recommended age and risk group
• For adults 60 or older: Daily low-dose aspirin is not recommended for primary prevention of heart disease, as the risks outweigh the benefits
• For adults aged 40–59: Daily low-dose aspirin may be considered if you have a 10% or higher risk of developing cardiovascular disease in the next 10 years

How the updated guidelines affect our approach

While these formal guidelines may be changing, Dr. Septimus says the shift isn't surprising — or new — to Houston Methodist's physicians.

"We stopped prescribing low-dose aspirin as a way to prevent heart attack and stroke in people who haven't yet developed significant heart and vascular disease years ago," says Dr. Septimus. "The guidelines will now simply reflect what we've already been practicing in the clinic for quite some time."

This isn't to say aspirin can't play a role in reducing the risk of experiencing a cardiovascular event for some — it can, especially if a person's risk is high. However, taking aspirin every day, even a low dose, comes with risks itself.

"Daily low-dose aspirin has its place in the heart disease prevention and treatment landscape, but it's certainly not always needed," Dr. Septimus adds.

How exactly does low-dose aspirin help prevent heart attack?

As a blood thinner, aspirin can help reduce the risk of plaque rupture, as well as some of the resulting clotting — thereby reducing the risk of heart attack and stroke in someone who has substantial buildup.

"If a person's blood vessels are narrowed due to plaque buildup, the arteries are in a diseased state called atherosclerosis," explains Dr. Septimus. "The more plaque, the more likely plaque rupture becomes. When this happens, it triggers a cascade of clotting and inflammation that can lead to heart attack and stroke."

Low-dose aspirin — sometimes called baby aspirin — is used for this purpose because it can effectively prevent clotting at lower amounts than the dosage needed for pain relief. These lower doses typically range between 75 and 100 milligrams, with 81 milligrams being the most common.

"The issue with aspirin, even at these low doses, is that it can cause gastrointestinal bleeding, ulcers and, in severe cases, hemorrhagic stroke," Dr. Septimus warns. "This means the benefits of taking aspirin every day must be carefully weighed against its risks. That's why we don't prescribe it unless a person actually has atherosclerosis."

What caused the low-dose aspirin guidelines to shift?

Low-dose aspirin has long been prescribed to help prevent heart disease and its complications. However, new data and evidence prompted the USPSTF to reassess its role, leading to finalized recommendations in 2022.

The changes focus on research showing that the side effects of daily aspirin — such as bleeding and stomach ulcers — often outweigh the benefits. For adults aged 60 or older, studies found no clear benefit in starting low-dose aspirin for primary prevention of heart disease.

"Our understanding of health and how best to prevent and treat disease is always evolving, and this shift in guidelines is just one example of that," says Dr. Septimus. "New information changed the way we approach heart attack and stroke prevention. These changes were already implemented in clinics, so the guidelines are being formally updated to reflect that."

Experts now recommend alternative prevention strategies for most older adults, emphasizing lifestyle changes instead. Rather than taking low-dose aspirin every day, your doctor may recommend the following:

• Adopting a heart healthy diet
• Getting plenty of exercise
• Monitoring your cholesterol and taking steps to control it if it's high
• Monitoring your blood pressure and managing if it's high
• Managing diabetes if you have it
• Stopping smoking if you smoke

Should I consider taking low-dose aspirin?

Daily aspirin use may be beneficial for certain individuals, but it's not recommended for everyone. Doctors typically prescribe it based on a history of heart disease, a high 10-year cardiovascular risk (10% or higher, as calculated by the ASCVD risk calculator) or through tests like a coronary artery calcium (CAC) score.

"The higher your CAC score, the more plaque you have in your arteries," says Dr. Septimus. "It's a much more accurate representation of your true risk of heart attack and stroke and can help confirm whether you might benefit from daily low-dose aspirin or not."

Most importantly, no daily medication should be started — or stopped — without consulting with your doctor. Talk to your healthcare provider to assess your risk factors and determine whether it's a safe and effective option for you.