Aspirin for Primary Prevention: Who Should Skip Daily Doses

For years, millions of people took a daily low-dose aspirin to prevent their first heart attack or stroke. It seemed simple: one pill, a cheap insurance policy against cardiovascular trouble. But the science has changed - and so should your decision. Today, for most healthy adults, aspirin is no longer a routine part of heart health. In fact, for many, it’s doing more harm than good.

Why the Rules Changed

Back in the 1990s, big studies showed aspirin lowered the risk of first heart attacks, especially in middle-aged men. That led to widespread recommendations. By 2016, nearly one in four U.S. adults between 40 and 79 were taking daily aspirin for prevention. But over time, researchers realized the benefits were smaller than thought - and the risks were bigger.

The biggest problem? Bleeding. Not just minor nosebleeds or bruising, but serious, life-threatening internal bleeding. A 2022 review by the U.S. Preventive Services Task Force (USPSTF) looked at 11 major trials involving over 100,000 people. They found that for every 1,000 people taking aspirin for 10 years, about 0.9 fewer heart attacks occurred. But 1.6 more people had major bleeding events - like stomach ulcers that required hospitalization or brain bleeds. That’s not a trade-off worth making for most people.

The American College of Cardiology and American Heart Association updated their guidelines in 2019 to match this new reality. They now say: don’t start aspirin for primary prevention unless you’re in a very specific group. And even then, only after careful discussion with your doctor.

Who Should Definitely Skip Aspirin

If you’re 60 or older and have never had a heart attack, stroke, stent, or bypass surgery - skip aspirin. That’s the clearest rule now. The USPSTF gives this a Grade D recommendation: “do not use.” Why? Because your risk of bleeding rises sharply with age, while your chance of preventing a first event drops.

Even if you’re in your 50s and feel perfectly healthy, you should still think twice. The only exception is if you have a 10-year risk of heart disease of 10% or higher - and even then, it’s not a yes. It’s a “maybe, after talking it through.”

Here’s who should avoid aspirin without question:

• Anyone with a history of stomach ulcers or gastrointestinal bleeding
• People taking blood thinners like warfarin, apixaban, or rivaroxaban
• Those regularly using NSAIDs like ibuprofen or naproxen
• Anyone with uncontrolled high blood pressure (systolic over 160)
• People with liver or kidney disease
• Anyone with a known bleeding disorder

These aren’t just theoretical risks. Data from Medicare shows 18.3% of adults over 65 are already on at least one other medication that increases bleeding risk. Adding aspirin to that mix isn’t smart - it’s dangerous.

Who Might Still Consider It (With Caution)

There are exceptions. But they’re narrow, and they require more than just a number on a chart.

If you’re between 40 and 59, and your 10-year risk of heart disease is 10% or higher - based on tools like the Pooled Cohort Equations - you and your doctor might consider aspirin. But only if you have no bleeding risk factors and you’re fully aware of the trade-offs.

Even then, some experts say you need more than just risk scores. For example:

• If your coronary calcium score (CAC) is over 100, your risk is higher than the average person with the same cholesterol numbers. Some cardiologists still recommend aspirin in this group.
• If you have diabetes and your CAC score is above 150, or your Lp(a) level is above 50 mg/dL, the benefit might tip slightly in favor of aspirin - but only if you’re under 70 and have no bleeding risks.

These aren’t blanket recommendations. They’re individualized calls. One 58-year-old woman with a CAC score of 350 and no other risk factors told her doctor: “I’d rather take the chance on aspirin than end up with a heart attack.” Her doctor agreed - after reviewing her full history and confirming she had no history of ulcers, no other blood thinners, and normal kidney function.

But another 58-year-old man with the same score had a past stomach bleed at 45. He was told to stop aspirin - and he did. Two years later, he’s still healthy, with no heart issues.

The Real Problem: Confusion and Fear

The biggest barrier isn’t science - it’s misunderstanding.

Many people think “if aspirin helped my dad after his heart attack, it should help me too.” But that’s secondary prevention - for people who already had a cardiac event. That’s different from primary prevention - stopping the first one. The rules are not the same.

A 2023 Mayo Clinic survey found 41% of adults over 60 were still taking aspirin daily, even after the guidelines changed. Why? Fear. “I don’t want to stop something that might be protecting me,” one patient said.

But here’s the truth: if you’ve never had a heart attack or stroke, and you’re over 60, aspirin is more likely to cause harm than prevent it. The number of people who need to take aspirin to prevent one heart attack is almost the same as the number who will have a serious bleed because of it.

And doctors aren’t always on the same page. A 2023 study in JAMA Internal Medicine found 57% of patients reported getting conflicting advice - primary care doctors were more likely to stop aspirin than cardiologists. That’s confusing. And it’s dangerous.

What to Do Instead

If you’re not taking aspirin for primary prevention, what should you do?

Focus on what actually works:

• Keep your blood pressure under control (under 130/80)
• Manage cholesterol - especially LDL
• Don’t smoke
• Get at least 150 minutes of walking or moderate exercise per week
• Eat a diet rich in vegetables, whole grains, nuts, and fish
• Keep your weight in a healthy range
• Check your blood sugar - especially if you’re overweight or have a family history

These steps reduce your heart disease risk by 80% or more - far more than aspirin ever could. And they don’t come with bleeding risks.

If you’re unsure about your risk, use the American Heart Association’s “Know Your Risk” tool. It’s free, easy to use, and gives you a personalized estimate based on your age, sex, blood pressure, cholesterol, and smoking status.

What If You’re Already Taking It?

If you’ve been on daily aspirin for years - especially if you’re over 60 - don’t stop cold turkey. Talk to your doctor. Stopping suddenly can cause a rebound effect in some people, though that’s rare.

Your doctor will likely ask:

• Have you ever had a stomach ulcer or bleeding?
• Are you on any other medications that thin your blood?
• What’s your 10-year heart disease risk?
• Have you had a coronary calcium scan?

If your risk is low and you’re over 60, stopping is almost certainly the right move. If you’re under 60 with high risk and no bleeding history, you might continue - but only with regular check-ins.

Looking Ahead

The future of heart disease prevention isn’t one-size-fits-all pills. It’s precision medicine. Researchers are now studying whether genetic tests can predict who will benefit from aspirin and who won’t. Early work suggests some people metabolize aspirin poorly - meaning it doesn’t work for them. Others have genes that make them more prone to bleeding.

A major trial called ASPRIN, funded by the NHLBI, is enrolling 15,000 people with high coronary calcium scores to see if aspirin helps them specifically. Results won’t come until 2028. Until then, stick to the current guidelines.

The message is clear: aspirin isn’t a magic bullet. For most healthy people, it’s not even a good idea. The days of popping a daily aspirin as a preventive habit are over. What’s better now? Knowing your numbers, managing your risks, and making smart, personalized choices - not following old habits.