Atrial fibrillation: Should I take anticoagulants to prevent stroke?
You may want to have a say in this decision, or you may simply want to follow your doctor's recommendation. Either way, this information will help you understand what your choices are so that you can talk to your doctor about them.
Atrial fibrillation: Should I take anticoagulants to prevent stroke?
Get the facts
Your options
- Take the anticoagulant medicine warfarin to reduce the risk of stroke.
- Don't take warfarin. You may try other medicines.
Key points to remember
- Atrial fibrillation increases your risk of stroke. High blood pressure, heart failure, a previous stroke, or being 75 or older can also put you at high risk for stroke. Taking the anticoagulant warfarin, lowers that risk.
- Warfarin may not be safe for you if you fall often, can't control your blood pressure, have stomach bleeding, or drink large amounts of alcohol.
- Aspirin may be a good choice if you are young and have no other heart or health problems or if you can't take warfarin safely. Aspirin doesn't work as well as warfarin to reduce your stroke risk. But aspirin is less likely to cause bleeding problems.
- When you take warfarin, you need to have regular blood tests to make sure that you are taking the right dose. You'll need to take enough medicine to lower your risk of stroke, but not so much that you have a problem with bleeding.
Why is it important to take medicine if you have atrial fibrillation?
Atrial fibrillation increases your risk of stroke. Taking warfarin can reduce that risk.
The risk of stroke isn't the same for everyone with atrial fibrillation. But people who have atrial fibrillation are 5 to 6 times more likely to have a stroke than are people who don't have atrial fibrillation.1
Warfarin can help protect against stroke, if you can take it safely. Your doctor may recommend that you take warfarin if you are at high risk for stroke based on your risk factors. Anything that increases your risk for a disease or problem is called a risk factor. The more risk factors you have, the greater your chance of having a stroke.
Risk factors for stroke besides atrial fibrillation include:
- Previous transient ischemic attack or stroke.
- An artificial heart valve.
- Rheumatic mitral valve disease .
- High blood pressure .
- Heart failure .
- Lower than normal ejection fraction.
- Age 75 years or older.
- Diabetes .
- Coronary artery disease .
If you are 55 or older, you can find out your risk of having a stroke in the next 5 years with this Interactive Tool: What Is Your Risk for a Stroke if You Have Atrial Fibrillation?
What are the risks of taking warfarin?
Warfarin slows the time it takes for your blood to clot. This increases your risk of bleeding problems in and around the brain, bleeding in the stomach and intestines, bruising and bleeding if you are hurt, and serious skin rash.
Some people can't take warfarin, because they have a higher risk of having a serious problem if bleeding occurs. You shouldn't take warfarin if:
- You have blood in your stool for no clear reason.
- You can't control your blood pressure.
- You fall often.
- You won't be able to take the steps needed to be safe when you take warfarin.
- You drink large amounts of alcohol.
- You aren't able or willing to have regular blood tests, which make sure that you are taking the right dose.
When you take warfarin, you need to take extra steps to avoid bleeding problems. For more information:
If you have atrial fibrillation and are pregnant or are thinking about getting pregnant, talk with your doctor before taking warfarin. It may cause birth defects and problems during pregnancy.
How well does warfarin work?
Warfarin significantly lowers the risk of stroke in people who have atrial fibrillation.2 But how much your risk will be lowered depends on how high your risk was to start with. Not everyone with atrial fibrillation has the same risk of stroke. It's a good idea to talk with your doctor about your risk.
You will want to weigh the benefits of reducing your risk of stroke with the risks of taking warfarin. Warfarin works well to prevent stroke. But warfarin also increases the risk of bleeding. Each year about 2 out of 100 people who take warfarin will have a problem with severe bleeding, and 98 will not.3 But this is an average risk. Your own risk may be higher or lower than average based on your own health.
What can you do instead of taking warfarin?
Aspirin may be a good choice if you are young and have no other heart or health problems or if you can't take warfarin safely. Aspirin doesn't work as well as warfarin to reduce your stroke risk. But aspirin is less likely to cause bleeding problems.
If you are at low risk for stroke or can't take warfarin, your doctor may recommend that you take aspirin. Aspirin is an antiplatelet medicine. It decreases the risk of blood clotting by preventing the smallest blood cells (platelets) from sticking together and making a clot.
Aspirin lowers the risk of stroke in people with atrial fibrillation but not nearly as much as warfarin does. How much your risk will be reduced depends on how high your risk was to start with.
Aspirin is less likely than warfarin to cause bleeding problems. Bleeding that is bad enough to need treatment in a hospital happens in 1 or 2 out of 1,000 people who take aspirin.4 This means that 998 or 999 out of 1,000 people who take aspirin don't have serious bleeding.
Other antiplatelet medicines, such as clopidogrel (Plavix), may be used. You may take them with aspirin or instead of aspirin. When aspirin and clopidogrel are used together, they may reduce the risk for stroke more than aspirin alone. But this combination is also more likely to cause bleeding than aspirin alone.
Why might your doctor recommend taking warfarin?
Your doctor may advise you to take warfarin if:
- Your risk of stroke is high and warfarin is the best treatment for you.
- You are able to take warfarin safely.
- You are willing and able to get regular blood tests.
Compare your options
Compare
|
What is usually involved? |
|
|
|
What are the benefits? |
|
|
|
What are the risks and side effects? |
|
|
- You take a pill every day.
- You have regular blood tests to make sure that you are taking the right dose.
- Warfarin lowers the risk of stroke by more than half (64%).2
- Warfarin increases your risk of bleeding problems.
- Warfarin may cause birth defects if you take it while you are pregnant.
- Warfarin lowers your risk, but you could still have a stroke.
- You may take aspirin every day to reduce your risk of stroke.
- You may try another antiplatelet medicine.
- Aspirin lowers the risk of stroke in people with atrial fibrillation, but not nearly as much as warfarin does.2
- Aspirin has a low risk of causing bleeding problems.
- You avoid the risks and costs of taking warfarin.
- If you have atrial fibrillation and don't take any medicine, you might have a stroke.
- Aspirin can reduce your risk, but you could still have a stroke. Your risk of having a stroke is higher than it would be if you took warfarin.
Personal stories
Are you interested in what others decided to do? Many people have faced this decision. These personal stories may help you decide.
Personal stories about taking warfarin
These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.
I have other risk factors for stroke besides atrial fibrillation. My doctor and I decided that it is important for me to take warfarin to help reduce my risk for having a stroke.
Monty, age 72
I live on a ranch more than 100 miles from my doctor's office. I don't plan on checking in with him every week to have my blood tested. Other than my atrial fibrillation, my doctor says my heart is strong as an ox and I'm healthy as a horse. I'm not worried about having a stroke, but I'm going to take aspirin every day.
Chuck, age 48
I am not overly concerned about bleeding problems from taking warfarin, and I am comfortable having my blood tested regularly to make sure the medications are working correctly.
Martha, age 64
I have a bleeding ulcer that I am caring for, so I am not a good candidate for blood thinners.
Geraldo, age 52
If you need more information, see the topic Atrial Fibrillation.
What matters most to you?
Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.
Reasons to take warfarin
Reasons not to take warfarin
I worry about my risk of stroke.
I think that my risk of stroke is low.
I don't mind having regular blood tests.
I'm don't want to get my blood tested regularly.
Lowering my risk of stroke is more important to me than the risk of a bleeding problem.
I'm more worried about my risk of a bleeding problem than my risk of stroke.
My other important reasons:
My other important reasons:
Where are you leaning now?
Now that you've thought about the facts and your feelings, you may have a general idea of where you stand on this decision. Show which way you are leaning right now.
Taking warfarin
NOT taking warfarin
What else do you need to make your decision?
Check the facts
If you have atrial fibrillation, are you at higher risk of stroke than someone who does not have it?
- Yes You're right. Atrial fibrillation increases your risk of stroke, but warfarin can reduce that risk.
- No Sorry, that's not right. Atrial fibrillation increases your risk of stroke, but warfarin can reduce that risk.
- I'm not sure It may help to go back and read "Why is it important to take medicine if you have atrial fibrillation?" Atrial fibrillation increases your risk of stroke, but warfarin can reduce that risk.
Is warfarin safe for everyone to take?
- Yes Sorry, that's not right. Warfarin may not be safe for you if you fall often, can't control your blood pressure, have stomach bleeding, or drink large amounts of alcohol.
- No You're right. Warfarin may not be safe for you if you fall often, can't control your blood pressure, have stomach bleeding, or drink large amounts of alcohol.
- I'm not sure It may help to go back and read "What are the risks of taking warfarin?" Warfarin may not be safe for you if you fall often, can't control your blood pressure, have stomach bleeding, or drink large amounts of alcohol.
Does aspirin work as well as warfarin to reduce the risk of stroke?
- Yes Sorry, that's not right. Aspirin doesn't work as well as warfarin to reduce the risk of stroke, but it is less likely to cause bleeding problems.
- No You are right. Aspirin doesn't work as well as warfarin to reduce your risk of stroke, but it is less likely to cause bleeding problems.
- I'm not sure It may help to go back and read "What can you do instead of taking warfarin?" Aspirin doesn't work as well as warfarin to reduce your risk of stroke, but it is less likely to cause bleeding problems.
Decide what's next
Do you understand the options available to you?
Are you clear about which benefits and side effects matter most to you?
Do you have enough support and advice from others to make a choice?
Certainty
How sure do you feel right now about your decision?
Check what you need to do before you make this decision.
Use the following space to list questions, concerns, and next steps.
Your summary
Here's a record of your answers. You can use it to talk with your doctor or loved ones about your decision.
Your decision
Next steps
Which way you're leaning
How sure you are
Your comments
Your knowledge of the facts
Key concepts that you understood
Key concepts that may need review
Getting ready to act
Patient choices
Credits and references
| Author | Robin Parks, MS |
| Editor | Kathleen M. Ariss, MS |
| Associate Editor | Pat Truman, MATC |
| Primary Medical Reviewer | Caroline S. Rhoads, MD - Internal Medicine |
| Specialist Medical Reviewer | John M. Miller, MD - Electrophysiology |
- Wang TJ, et al. (2003). A risk score for predicting stroke or death in individuals with new-onset atrial fibrillation in the community: The Framingham heart study. JAMA, 290(8): 1049–1056.
- Hart R, et al. (2007). Meta-analysis: Antithrombotic therapy to prevent stroke in patients who have nonvalvular atrial fibrillation. Annals of Internal Medicine, 146: 857–867.
- Antiplatelet and anticoagulant drugs (2008). Treatment Guidelines From The Medical Letter, 6(69): 29–36.
- Patrono C, et al. (2008). Antiplatelet drugs: American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). Chest, 133(6): 199S–233S.
Atrial fibrillation: Should I take anticoagulants to prevent stroke?
- Get the facts
- Compare your options
- What matters most to you?
- Where are you leaning now?
- What else do you need to make your decision?
1. Get the facts
Your options
- Take the anticoagulant medicine warfarin to reduce the risk of stroke.
- Don't take warfarin. You may try other medicines.
Key points to remember
- Atrial fibrillation increases your risk of stroke. High blood pressure, heart failure, a previous stroke, or being 75 or older can also put you at high risk for stroke. Taking the anticoagulant warfarin, lowers that risk.
- Warfarin may not be safe for you if you fall often, can't control your blood pressure, have stomach bleeding, or drink large amounts of alcohol.
- Aspirin may be a good choice if you are young and have no other heart or health problems or if you can't take warfarin safely. Aspirin doesn't work as well as warfarin to reduce your stroke risk. But aspirin is less likely to cause bleeding problems.
- When you take warfarin, you need to have regular blood tests to make sure that you are taking the right dose. You'll need to take enough medicine to lower your risk of stroke, but not so much that you have a problem with bleeding.
What are anticoagulants?
Why is it important to take medicine if you have atrial fibrillation?
Atrial fibrillation increases your risk of stroke. Taking warfarin can reduce that risk.
The risk of stroke isn't the same for everyone with atrial fibrillation. But people who have atrial fibrillation are 5 to 6 times more likely to have a stroke than are people who don't have atrial fibrillation.1
Warfarin can help protect against stroke, if you can take it safely. Your doctor may recommend that you take warfarin if you are at high risk for stroke based on your risk factors. Anything that increases your risk for a disease or problem is called a risk factor. The more risk factors you have, the greater your chance of having a stroke.
Risk factors for stroke besides atrial fibrillation include:
- Previous transient ischemic attack or stroke.
- An artificial heart valve.
- Rheumatic mitral valve disease .
- High blood pressure .
- Heart failure .
- Lower than normal ejection fraction.
- Age 75 years or older.
- Diabetes .
- Coronary artery disease .
If you are 55 or older, you can find out your risk of having a stroke in the next 5 years with this Interactive Tool: What Is Your Risk for a Stroke if You Have Atrial Fibrillation?
What are the risks of taking warfarin?
Warfarin slows the time it takes for your blood to clot. This increases your risk of bleeding problems in and around the brain, bleeding in the stomach and intestines, bruising and bleeding if you are hurt, and serious skin rash.
Some people can't take warfarin, because they have a higher risk of having a serious problem if bleeding occurs. You shouldn't take warfarin if:
- You have blood in your stool for no clear reason.
- You can't control your blood pressure.
- You fall often.
- You won't be able to take the steps needed to be safe when you take warfarin.
- You drink large amounts of alcohol.
- You aren't able or willing to have regular blood tests, which make sure that you are taking the right dose.
When you take warfarin, you need to take extra steps to avoid bleeding problems. For more information:
If you have atrial fibrillation and are pregnant or are thinking about getting pregnant, talk with your doctor before taking warfarin. It may cause birth defects and problems during pregnancy.
How well does warfarin work?
Warfarin significantly lowers the risk of stroke in people who have atrial fibrillation.2 But how much your risk will be lowered depends on how high your risk was to start with. Not everyone with atrial fibrillation has the same risk of stroke. It's a good idea to talk with your doctor about your risk.
You will want to weigh the benefits of reducing your risk of stroke with the risks of taking warfarin. Warfarin works well to prevent stroke. But warfarin also increases the risk of bleeding. Each year about 2 out of 100 people who take warfarin will have a problem with severe bleeding, and 98 will not.3 But this is an average risk. Your own risk may be higher or lower than average based on your own health.
What can you do instead of taking warfarin?
Aspirin may be a good choice if you are young and have no other heart or health problems or if you can't take warfarin safely. Aspirin doesn't work as well as warfarin to reduce your stroke risk. But aspirin is less likely to cause bleeding problems.
If you are at low risk for stroke or can't take warfarin, your doctor may recommend that you take aspirin. Aspirin is an antiplatelet medicine. It decreases the risk of blood clotting by preventing the smallest blood cells (platelets) from sticking together and making a clot.
Aspirin lowers the risk of stroke in people with atrial fibrillation but not nearly as much as warfarin does. How much your risk will be reduced depends on how high your risk was to start with.
Aspirin is less likely than warfarin to cause bleeding problems. Bleeding that is bad enough to need treatment in a hospital happens in 1 or 2 out of 1,000 people who take aspirin.4 This means that 998 or 999 out of 1,000 people who take aspirin don't have serious bleeding.
Other antiplatelet medicines, such as clopidogrel (Plavix), may be used. You may take them with aspirin or instead of aspirin. When aspirin and clopidogrel are used together, they may reduce the risk for stroke more than aspirin alone. But this combination is also more likely to cause bleeding than aspirin alone.
Why might your doctor recommend taking warfarin?
Your doctor may advise you to take warfarin if:
- Your risk of stroke is high and warfarin is the best treatment for you.
- You are able to take warfarin safely.
- You are willing and able to get regular blood tests.
2. Compare your options
| Take warfarin to reduce the risk of stroke | Don't take warfarin | |
|---|---|---|
| What is usually involved? |
|
|
| What are the benefits? |
|
|
| What are the risks and side effects? |
|
|
Personal stories
Are you interested in what others decided to do? Many people have faced this decision. These personal stories may help you decide.
If you need more information, see the topic Atrial Fibrillation.
Personal stories about taking warfarin
These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.
"I have other risk factors for stroke besides atrial fibrillation. My doctor and I decided that it is important for me to take warfarin to help reduce my risk for having a stroke."
— Monty, age 72
"I live on a ranch more than 100 miles from my doctor's office. I don't plan on checking in with him every week to have my blood tested. Other than my atrial fibrillation, my doctor says my heart is strong as an ox and I'm healthy as a horse. I'm not worried about having a stroke, but I'm going to take aspirin every day."
— Chuck, age 48
"I am not overly concerned about bleeding problems from taking warfarin, and I am comfortable having my blood tested regularly to make sure the medications are working correctly."
— Martha, age 64
"I have a bleeding ulcer that I am caring for, so I am not a good candidate for blood thinners."
— Geraldo, age 52
3. What matters most to you?
Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.
Reasons to take warfarin
Reasons not to take warfarin
I worry about my risk of stroke.
I think that my risk of stroke is low.
I don't mind having regular blood tests.
I'm don't want to get my blood tested regularly.
Lowering my risk of stroke is more important to me than the risk of a bleeding problem.
I'm more worried about my risk of a bleeding problem than my risk of stroke.
My other important reasons:
My other important reasons:
4. Where are you leaning now?
Now that you've thought about the facts and your feelings, you may have a general idea of where you stand on this decision. Show which way you are leaning right now.
Taking warfarin
NOT taking warfarin
5. What else do you need to make your decision?
Check the facts
1. If you have atrial fibrillation, are you at higher risk of stroke than someone who does not have it?
- Yes
- No
- I'm not sure
2. Is warfarin safe for everyone to take?
- Yes
- No
- I'm not sure
3. Does aspirin work as well as warfarin to reduce the risk of stroke?
- Yes
- No
- I'm not sure
Decide what's next
1. Do you understand the options available to you?
2. Are you clear about which benefits and side effects matter most to you?
3. Do you have enough support and advice from others to make a choice?
Certainty
1. How sure do you feel right now about your decision?
2. Check what you need to do before you make this decision.
- I'm ready to take action.
- I want to discuss the options with others.
- I want to learn more about my options.
3. Use the following space to list questions, concerns, and next steps.
| Author | Robin Parks, MS |
| Editor | Kathleen M. Ariss, MS |
| Associate Editor | Pat Truman, MATC |
| Primary Medical Reviewer | Caroline S. Rhoads, MD - Internal Medicine |
| Specialist Medical Reviewer | John M. Miller, MD - Electrophysiology |
- Wang TJ, et al. (2003). A risk score for predicting stroke or death in individuals with new-onset atrial fibrillation in the community: The Framingham heart study. JAMA, 290(8): 1049–1056.
- Hart R, et al. (2007). Meta-analysis: Antithrombotic therapy to prevent stroke in patients who have nonvalvular atrial fibrillation. Annals of Internal Medicine, 146: 857–867.
- Antiplatelet and anticoagulant drugs (2008). Treatment Guidelines From The Medical Letter, 6(69): 29–36.
- Patrono C, et al. (2008). Antiplatelet drugs: American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). Chest, 133(6): 199S–233S.
Note: The "printer friendly" document will not contain all the information available in the online document some Information (e.g. cross-references to other topics, definitions or medical illustrations) is only available in the online version.
Last Updated: December 29, 2008
Author: Robin Parks, MS
Medical Review: Caroline S. Rhoads, MD - Internal Medicine & John M. Miller, MD - Electrophysiology
