Aspirin may help prevent a heart attack in some people, but it is not recommended for everyone to prevent coronary artery disease (CAD). It makes platelets less likely to form clots; it does not remove fatty plaque from artery walls. For people who have never had heart disease, a possible benefit must be weighed against serious bleeding risk. Do not start daily aspirin without medical advice.
How does aspirin affect the risk of coronary artery disease?
Coronary artery disease develops when fatty deposits, called plaque, build up inside the arteries that supply blood to the heart. Over time, this buildup can narrow the arteries and reduce blood flow. If a plaque ruptures, a blood clot may form and block blood flow, potentially causing a heart attack.
Aspirin works by reducing the ability of platelets, small blood cells that help blood clot, to stick together. The American Heart Association explains that aspirin can help prevent blood clots and is often included in treatment plans for people who have experienced a heart attack or stroke.
However, aspirin does not directly prevent the buildup of cholesterol-rich plaque. It is an antiplatelet medicine, not a cholesterol-lowering drug. Its main preventive benefit is related to reducing certain clot-related cardiovascular events, and that benefit depends on a person's existing heart disease, overall cardiovascular risk, and likelihood of bleeding.
Should healthy adults take aspirin to prevent a first heart attack?
For most adults who have never had a heart attack, stroke, or diagnosed cardiovascular disease, taking aspirin every day is not routinely recommended. Research has found that although aspirin can reduce some cardiovascular events in selected people, the absolute benefit for primary prevention is generally small. Bleeding complications can offset that benefit.
The US Preventive Services Task Force (USPSTF) recommends that adults aged 40–59 years with an estimated 10% or greater risk of cardiovascular disease over the next 10 years make an individual decision with their healthcare professional about starting low-dose aspirin. The expected net benefit is small, and the recommendation applies to people who are not at increased risk of bleeding. The USPSTF recommends against starting aspirin for primary prevention in adults aged 60 years or older.
These recommendations concern preventing a first cardiovascular event, rather than treating people with established heart disease. They also reflect US guidance, which may differ from recommendations used in other countries.
Does age change whether aspirin is a good choice?
Age affects both cardiovascular risk and the likelihood of bleeding. Although older adults may have a greater chance of a heart attack or stroke, they also face a higher risk of serious bleeding from aspirin. As a result, taking aspirin solely to prevent a first heart attack is less likely to offer a favorable balance of benefits and harms with increasing age.
The American College of Cardiology (ACC), describing the 2019 American College of Cardiology/American Heart Association guideline, states that low-dose aspirin may be considered for selected adults aged 40–70 years who have higher cardiovascular risk and no increased bleeding risk. Routine use is not recommended for primary prevention in adults older than 70 years or in people with increased bleeding risk.
Because recommendations differ slightly among organizations, age alone should not determine an individual's treatment. A healthcare professional can consider overall cardiovascular risk, medical history, other medicines, and bleeding risk before discussing whether aspirin is appropriate.
When can aspirin help prevent another heart attack?
Aspirin has a more established role in secondary prevention. This means preventing another cardiovascular event in someone who already has diagnosed cardiovascular disease or has experienced an event such as a heart attack. It may also be prescribed after certain coronary procedures, including stent placement or coronary artery bypass surgery.
In these situations, the risk of another clot-related event may be high enough for the benefits of aspirin to outweigh its risks. The dose and duration depend on the reason for treatment and the person's clinical circumstances. Some people who undergo coronary procedures may need aspirin alongside another antiplatelet medicine for a specified period.
If aspirin has already been prescribed after a heart attack, stent placement, or bypass surgery, do not stop taking it without speaking to the prescribing healthcare professional. The decision to continue or change treatment depends on why it was prescribed and the balance between clotting and bleeding risks.
What are the risks of taking aspirin every day?
Aspirin can cause bleeding because it reduces the blood's ability to form clots. The Mayo Clinic identifies gastrointestinal bleeding, stomach ulcers, and bleeding strokes among the possible complications of daily aspirin use. Some bleeding can be serious or life-threatening, even when the aspirin dose is low.
The likelihood of harm may be higher in people with certain medical conditions or medication combinations. Before recommending daily aspirin, a healthcare professional may consider factors such as:
- A previous stomach ulcer or gastrointestinal bleeding.
- A history of bleeding or conditions that increase bleeding risk.
- Older age, particularly when aspirin is being considered to prevent a first cardiovascular event.
- Use of anticoagulants, other antiplatelet medicines, or medicines such as ibuprofen that may increase bleeding risk.
- An allergy or serious reaction to aspirin.
Taking a smaller dose does not eliminate the risk of bleeding. Enteric-coated or delayed-release aspirin should not be assumed to remove that risk either. Tell your healthcare professional about all prescription medicines, over-the-counter pain relievers, and supplements you use before starting aspirin regularly.
What is more effective for preventing coronary artery disease?
Preventing the development or progression of coronary artery disease generally requires attention to the factors that contribute to plaque buildup and cardiovascular risk. Aspirin cannot replace measures that address high cholesterol, high blood pressure, diabetes, tobacco use, and other relevant risk factors.
The National Heart, Lung, and Blood Institute (NHLBI) identifies heart-healthy living as an important way to prevent or delay coronary heart disease and its complications. Practical steps include:
- Choose heart-healthy foods. Emphasize vegetables, fruits, whole grains, and other nutritious foods while limiting excess salt, added sugars, and unhealthy fats.
- Stay physically active. Regular activity can help manage several cardiovascular risk factors. Choose an activity level appropriate for your health and abilities.
- Avoid tobacco. Smoking damages blood vessels and increases the risk of coronary heart disease. Quitting can improve heart health.
- Manage blood pressure, cholesterol, and blood sugar. Regular health checks can help identify problems that may benefit from lifestyle changes or medication.
- Use prescribed preventive medicines when appropriate. Depending on individual risk, treatment may include cholesterol-lowering medicines, blood pressure medicines, or diabetes treatment.
These steps address important contributors to cardiovascular disease rather than focusing only on clot formation. A healthcare professional can help prioritize them according to personal risk factors, family history, test results, and existing medical conditions.
How can you decide whether daily aspirin is right for you?
The decision should begin with a clear distinction between preventing a first cardiovascular event and preventing another one. For primary prevention, the potential benefit of aspirin is often modest, so bleeding risk becomes especially important. For people with established coronary artery disease or a previous heart attack, aspirin may have a stronger role in preventing further events.
During a medical review, a healthcare professional may assess age, blood pressure, cholesterol, diabetes, smoking history, family history, previous cardiovascular events, and medicines that increase bleeding risk. They can then explain whether aspirin offers a meaningful benefit compared with other prevention strategies.
The key point is that aspirin can reduce the risk of certain clot-related cardiovascular events, but it does not prevent every cause of coronary artery disease. For people without known cardiovascular disease, taking it daily should be a carefully considered decision rather than a routine habit.