“I should be taking aspirin, right?”
Jeff, a 60-year-old patient, wants to make sure he’s doing everything he can to guard himself against a heart attack. Though he doesn’t have a history of heart disease, he does have risk factors, including high blood pressure and high cholesterol, so he’s wise to stay vigilant.
There are number of things Jeff can do to stay healthy – stay physically active, eat nutritious food, and control his blood pressure and cholesterol. But what about aspirin? Should Jeff take aspirin to lower his risk of future heart disease?
The answer is not as clear as you might think.
What Does Aspirin Do?
Aspirin is an amazing medication with many benefits. It can be used to reduce fever, pain, and inflammation, but the reason it is beneficial in heart disease is because it blocks platelets from joining together. This “anti-platelet” effect of aspirin decreases the ability of blood to form blood clots and makes it useful in treating and preventing heart attacks and strokes.
But there is a downside to less clotting: More bleeding. Aspirin use can result in a small, but significant, increase in major bleeding (defined as needing a transfusion or surgery or bleeding in the brain).
Does Aspirin Really Prevent Heart Disease?
The answer is, “absolutely yes.” Aspirin has been shown to not only be effective in treating heart attacks and strokes when they occur, but it can also lower the future risk of heart attacks and stroke. The better – and more complicated – question is, “Do the benefits of aspirin outweigh the increased risk of bleeding?”
And to answer that question, we need to know more about the person asking. Do they have heart disease already? If not, what is their risk for heart disease in the future? What is their risk for bleeding? And, interestingly, what is their risk for colon cancer (because aspirin has been shown to modestly lower the risk for colon cancer)?
Aspirin in Secondary Prevention
For secondary prevention, (those who have had a heart attack, stroke, stents or bypass surgery), the research data is conclusive: Aspirin provides more benefit than risk for the majority of people.
However, in primary prevention (those who have not had a heart attack, stroke, stent or bypass surgery), the benefits versus the risk of aspirin is less certain.
Aspirin in Primary Prevention
My patients who do not have heart disease are often surprised when I tell them that aspirin may not be right for them. The idea that aspirin is good for your heart has been around for so long that many believe it to be an established fact. However, several research studies in recent years have shown that the benefits are not as definite as many think.
And more research isn’t likely to clarify the issue because the problem is not lack of data – it’s that the benefits – and risks – of aspirin are relatively small.
The American College of Chest Physicians Guidelines 9th Edition provides perhaps the easiest to understand summary of the risks and benefits of aspirin. The authors calculated the risks and benefits for 1,000 men and women who take aspirin daily for 10 years.
Men: Risks and benefits of 10 years of aspirin use in 1,000 60-year-old men:
- 6 less deaths
- Up to 27 fewer heart attacks
- Up to 24 fewer colon cancers
- Up to 22 more major bleeding episodes
- No change in strokes
Women: Risks and benefits of 10 years of aspirin use in 1,000 60-year-old women:
- Up to 14 fewer strokes
- Up to 24 fewer colon cancers
- Up to 20 more major bleeding episodes
- No change in heart attacks or death
As you can see from these data, the benefits – and risks – of aspirin use in those who have not had heart disease is small.
What Do I Tell My Patients?
For my patients who do not have heart disease, but are considering aspirin, here are my guidelines to help them decide if aspirin is right for them:
- If the person has side effects to aspirin (like upset stomach, easy bleeding or allergy), I do not recommend aspirin.
- If the person is at high risk for heart disease and colon cancer, aspirin is likely of more benefit than harm.
- If the patient is at low risk for heart disease and colon cancer, aspirin is likely of limited benefit.
For Jeff, because his risk of heart disease is high, he decided that a daily aspirin was right for him.
The last important point is the dose of aspirin. If you are taking aspirin for heart protection reasons, the 81 mg dose (also called “baby aspirin” is as effective as the full-strength version (325 mg), but with less bleeding risk. Therefore, aspirin 81 mg is recommended for most people.
If you are considering aspirin – and do not have a history of heart disease or stroke – talk to your doctor to see if aspirin is right for you.
Dr. Hurst gratefully acknowledges the contribution of Alexandra Winski in the creation of this article.