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Atrial Fibrillation: Should I Take an Anticoagulant 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 an Anticoagulant to Prevent Stroke?

Get the facts

Your options

  • Take an anticoagulant medicine to reduce the risk of stroke.
  • Don't take an anticoagulant. You may try aspirin or do nothing.

Key points to remember

  • Atrial fibrillation increases your risk of stroke. Other things that raise your risk include heart failure, high blood pressure, a previous stroke, and diabetes. Your doctor can help you know your risk. Taking an anticoagulant lowers that risk.
  • When you take an anticoagulant, also called a blood thinner, you need to take extra steps to avoid bleeding problems, such as preventing falls and injuries.
  • Depending on the type of anticoagulant you take, you may have to get regular blood tests and watch how much vitamin K you eat or drink.
  • Aspirin may be a good choice if you are young and have no other heart or health problems or if you can't take an anticoagulant safely. Aspirin doesn't work as well as an anticoagulant to reduce your stroke risk. But aspirin is less likely to cause bleeding problems.
FAQs

What are anticoagulants?

Anticoagulants are medicines that help prevent blood clots. Blood clots can lead to stroke. These medicines are often called blood thinners, but they don't actually thin your blood. Instead, they increase the time it takes for a blood clot to form.

Anticoagulants used for atrial fibrillation are warfarin (Coumadin), dabigatran (Pradaxa), and rivaroxaban (Xarelto).

How can medicine help if you have atrial fibrillation?

Atrial fibrillation increases your risk of stroke. Taking an anticoagulant can reduce that risk.

The risk of stroke isn't the same for everyone who has atrial fibrillation. But on average, people who have atrial fibrillation are 5 times more likely to have a stroke than people who don't have atrial fibrillation.1 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.

Anticoagulants can help protect against stroke. Your doctor may recommend that you take an anticoagulant if you are at high risk for stroke based on your risk factors.

Your doctor can check your risk of a stroke. Things that can raise your risk include:

  • Age. Being older than 65 raises your risk.
  • Gender. Being a woman raises your risk.
  • Heart failure.
  • High blood pressure.
  • A previous stroke or transient ischemic attack (TIA).
  • Heart attack, peripheral arterial disease, or other blood vessel disease.
  • Diabetes.

What are the risks of taking an anticoagulant?

When you take an anticoagulant, your blood clots more slowly than normal. 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 anticoagulants, because they have a higher risk of having a serious problem if bleeding occurs. Your own risk of bleeding may be higher or lower based on your health. For example, you may have a higher risk of bleeding if you have uncontrolled high blood pressure, have kidney or liver disease, or drink large amounts of alcohol.

When you take an anticoagulant, also called a blood thinner, you need to take extra steps to avoid bleeding problems, such as preventing falls and injuries. With the anticoagulant warfarin, you also need to have regular blood tests to make sure you are taking the right dose. And you need to watch how much vitamin K you eat or drink.

You will want to weigh the benefits of reducing your risk of stroke against the risks of taking an anticoagulant, such as an increased risk of bleeding. For example, each year about 1 to 3 out of 100 people (or 10 to 30 out of 1,000 people) who take an anticoagulant will have a problem with severe bleeding. This means that 97 to 99 out of 100 people (or 970 to 990 out of 1,000 people) will not have a bleeding problem.2, 3, 4, 5 But these are average risks. Your own risk may be higher or lower than average based on your own health.

How well do anticoagulants work?

Anticoagulants lower the risk of stroke in people who have atrial fibrillation. 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.

What can you do instead of taking an anticoagulant?

Aspirin may be a good choice if you are young and have no other heart or health problems or if you can't take an anticoagulant (blood thinner) safely. Aspirin doesn't work as well as an anticoagulant to reduce your stroke risk.6

If you are at low risk for stroke or can't take an anticoagulant, your doctor may recommend that you take aspirin. Aspirin is an antiplatelet medicine. It reduces the risk of blood clotting by preventing the smallest blood cells (platelets) from sticking together and making a clot.

Aspirin is less likely than an anticoagulant 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.7 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. Your doctor may have you 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. This combination of clopidogrel and aspirin doesn't work as well as an anticoagulant to prevent clots. This combination is also more likely to cause bleeding than aspirin alone.8

Why might your doctor recommend taking an anticoagulant?

Your doctor may advise you to take an anticoagulant if:

  • Your risk of stroke is high and an anticoagulant is the best treatment for you.
  • You are willing and able to take the medicine as directed. This includes taking care to prevent falls and getting regular blood tests if needed.

Compare your options

Compare

What is usually involved?









What are the benefits?









What are the risks and side effects?









Take an anticoagulant to reduce the risk of stroke Take an anticoagulant to reduce the risk of stroke
  • You take a pill once or twice a day.
  • If you take warfarin, you will have regular blood tests to make sure that you are taking the right dose.
  • If you take warfarin, you will try to eat and drink about the same amount of vitamin K each day.
  • You'll need to let your doctor know of any new medicines you start taking while you are taking an anticoagulant.
  • Anticoagulants lower the risk of stroke in people who have atrial fibrillation.
  • Anticoagulants increase your risk of bleeding problems.
  • Anticoagulants lower your risk of stroke, but you could still have a stroke.
Don't take an anticoagulant Don't take an anticoagulant
  • You may take aspirin every day to reduce your risk of stroke.
  • You may try another antiplatelet medicine such as clopidogrel (Plavix).
  • Aspirin lowers the risk of stroke in people who have atrial fibrillation. But aspirin doesn't work as well as anticoagulants to reduce stroke risk.
  • Aspirin is less likely than an anticoagulant to cause bleeding problems.
  • You don't need regular blood tests to check the medicine dose, as you do with warfarin.
  • You don't have to watch how much vitamin K you eat or drink, as you do with the anticoagulant 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 an anticoagulant (blood thinner).

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 anticoagulants

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 a blood thinner to help reduce my risk for having a stroke.

Monty, age 72

I have a lot of balance problems. They might get better over time, but I do worry about falling. And my doctor says my stroke risk is low. I think I'll stick with aspirin for now.

Juan, age 67

I am not overly concerned about bleeding problems from taking a blood thinner, and I'm motivated to follow the instructions to take it as directed.

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

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 an anticoagulant

Reasons not to take an anticoagulant

I worry about my risk of stroke.

My risk of stroke is low.

More important
Equally important
More important

I'm confident that I can take an anticoagulant as directed.

I'm worried that I can't take an anticoagulant as directed.

More important
Equally important
More important

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.

More important
Equally important
More important

My other important reasons:

My other important reasons:

More important
Equally important
More important

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 an anticoagulant

NOT taking an anticoagulant

Leaning toward
Undecided
Leaning toward

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 doesn't have it?

  • YesYou're right. Atrial fibrillation increases your risk of stroke, but anticoagulants can reduce that risk.
  • NoSorry, that's not right. Atrial fibrillation increases your risk of stroke, but anticoagulants can reduce that risk.
  • I'm not sureIt may help to go back and read "Get the Facts." Atrial fibrillation increases your risk of stroke, but anticoagulants can reduce that risk.
2.

Are anticoagulants safe for everyone to take?

  • YesSorry, that's not right. Anticoagulants may not be safe for you if you can't control your blood pressure, have stomach bleeding, or drink large amounts of alcohol.
  • NoYou're right. Anticoagulants may not be safe for you if you can't control your blood pressure, have stomach bleeding, or drink large amounts of alcohol.
  • I'm not sureIt may help to go back and read "Get the Facts." Anticoagulants may not be safe for you if you can't control your blood pressure, have stomach bleeding, or drink large amounts of alcohol.
3.

Does aspirin work as well as anticoagulants to reduce the risk of stroke?

  • YesSorry, that's not right. Aspirin doesn't work as well as anticoagulants to reduce the risk of stroke, but it is less likely to cause bleeding problems.
  • NoYou're right. Aspirin doesn't work as well as anticoagulants to reduce your risk of stroke, but it is less likely to cause bleeding problems.
  • I'm not sureIt may help to go back and read "Get the Facts." Aspirin doesn't work as well as anticoagulants to reduce your risk of stroke, but it is less likely to cause bleeding problems.

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?

Not sure at all
Somewhat sure
Very sure
3.

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

Credits
Author Healthwise Staff
Primary Medical Reviewer Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
Specialist Medical Reviewer John M. Miller, MD, FACC - Cardiology, Electrophysiology

References
Citations
  1. Prevention of stroke in patients with atrial fibrillation (2009). Medical Letter on Drugs and Therapeutics, 51(1313): 41.
  2. Antithrombotic drugs (2011). Treatment Guidelines From The Medical Letter, 9(110): 61–66.
  3. Dabigatran etexilate (Pradaxa)—A new oral anticoagulant (2010). Medical Letter on Drugs and Therapeutics, 52(1351): 89–90.
  4. Patel MR, et al. (2011). Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. New England Journal of Medicine, 365(10): 883–891.
  5. Granger CB, et al. (2011). Apixaban versus warfarin in patients with atrial fibrillation. New England Journal of Medicine, 365(11): 981–992.
  6. Fuster V, et al. (2011). 2011 ACCF/AHA/HRS focused update incorporated into the ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation, 123(10): e269–e367.
  7. Paikin JS, Eikelboom JW (2012). Aspirin. Circulation, 125(10): e439–e442.
  8. ACTIVE Investigators (2009). Effect of clopidogrel added to aspirin in patients with atrial fibrillation. New England Journal of Medicine, 360(20): 2066–2078.
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 an Anticoagulant to Prevent Stroke?

Here's a record of your answers. You can use it to talk with your doctor or loved ones about your decision.
  1. Get the facts
  2. Compare your options
  3. What matters most to you?
  4. Where are you leaning now?
  5. What else do you need to make your decision?

1. Get the Facts

Your options

  • Take an anticoagulant medicine to reduce the risk of stroke.
  • Don't take an anticoagulant. You may try aspirin or do nothing.

Key points to remember

  • Atrial fibrillation increases your risk of stroke. Other things that raise your risk include heart failure, high blood pressure, a previous stroke, and diabetes. Your doctor can help you know your risk. Taking an anticoagulant lowers that risk.
  • When you take an anticoagulant, also called a blood thinner, you need to take extra steps to avoid bleeding problems, such as preventing falls and injuries.
  • Depending on the type of anticoagulant you take, you may have to get regular blood tests and watch how much vitamin K you eat or drink.
  • Aspirin may be a good choice if you are young and have no other heart or health problems or if you can't take an anticoagulant safely. Aspirin doesn't work as well as an anticoagulant to reduce your stroke risk. But aspirin is less likely to cause bleeding problems.
FAQs

What are anticoagulants?

Anticoagulants are medicines that help prevent blood clots. Blood clots can lead to stroke. These medicines are often called blood thinners, but they don't actually thin your blood. Instead, they increase the time it takes for a blood clot to form.

Anticoagulants used for atrial fibrillation are warfarin (Coumadin), dabigatran (Pradaxa), and rivaroxaban (Xarelto).

How can medicine help if you have atrial fibrillation?

Atrial fibrillation increases your risk of stroke. Taking an anticoagulant can reduce that risk.

The risk of stroke isn't the same for everyone who has atrial fibrillation. But on average, people who have atrial fibrillation are 5 times more likely to have a stroke than people who don't have atrial fibrillation.1 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.

Anticoagulants can help protect against stroke. Your doctor may recommend that you take an anticoagulant if you are at high risk for stroke based on your risk factors.

Your doctor can check your risk of a stroke. Things that can raise your risk include:

  • Age. Being older than 65 raises your risk.
  • Gender. Being a woman raises your risk.
  • Heart failure.
  • High blood pressure.
  • A previous stroke or transient ischemic attack (TIA).
  • Heart attack, peripheral arterial disease, or other blood vessel disease.
  • Diabetes.

What are the risks of taking an anticoagulant?

When you take an anticoagulant, your blood clots more slowly than normal. 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 anticoagulants, because they have a higher risk of having a serious problem if bleeding occurs. Your own risk of bleeding may be higher or lower based on your health. For example, you may have a higher risk of bleeding if you have uncontrolled high blood pressure, have kidney or liver disease, or drink large amounts of alcohol.

When you take an anticoagulant, also called a blood thinner, you need to take extra steps to avoid bleeding problems, such as preventing falls and injuries. With the anticoagulant warfarin, you also need to have regular blood tests to make sure you are taking the right dose. And you need to watch how much vitamin K you eat or drink.

You will want to weigh the benefits of reducing your risk of stroke against the risks of taking an anticoagulant, such as an increased risk of bleeding. For example, each year about 1 to 3 out of 100 people (or 10 to 30 out of 1,000 people) who take an anticoagulant will have a problem with severe bleeding. This means that 97 to 99 out of 100 people (or 970 to 990 out of 1,000 people) will not have a bleeding problem.2, 3, 4, 5 But these are average risks. Your own risk may be higher or lower than average based on your own health.

How well do anticoagulants work?

Anticoagulants lower the risk of stroke in people who have atrial fibrillation. 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.

What can you do instead of taking an anticoagulant?

Aspirin may be a good choice if you are young and have no other heart or health problems or if you can't take an anticoagulant (blood thinner) safely. Aspirin doesn't work as well as an anticoagulant to reduce your stroke risk.6

If you are at low risk for stroke or can't take an anticoagulant, your doctor may recommend that you take aspirin. Aspirin is an antiplatelet medicine. It reduces the risk of blood clotting by preventing the smallest blood cells (platelets) from sticking together and making a clot.

Aspirin is less likely than an anticoagulant 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.7 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. Your doctor may have you 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. This combination of clopidogrel and aspirin doesn't work as well as an anticoagulant to prevent clots. This combination is also more likely to cause bleeding than aspirin alone.8

Why might your doctor recommend taking an anticoagulant?

Your doctor may advise you to take an anticoagulant if:

  • Your risk of stroke is high and an anticoagulant is the best treatment for you.
  • You are willing and able to take the medicine as directed. This includes taking care to prevent falls and getting regular blood tests if needed.

2. Compare your options

  Take an anticoagulant to reduce the risk of stroke Don't take an anticoagulant
What is usually involved?
  • You take a pill once or twice a day.
  • If you take warfarin, you will have regular blood tests to make sure that you are taking the right dose.
  • If you take warfarin, you will try to eat and drink about the same amount of vitamin K each day.
  • You'll need to let your doctor know of any new medicines you start taking while you are taking an anticoagulant.
  • You may take aspirin every day to reduce your risk of stroke.
  • You may try another antiplatelet medicine such as clopidogrel (Plavix).
What are the benefits?
  • Anticoagulants lower the risk of stroke in people who have atrial fibrillation.
  • Aspirin lowers the risk of stroke in people who have atrial fibrillation. But aspirin doesn't work as well as anticoagulants to reduce stroke risk.
  • Aspirin is less likely than an anticoagulant to cause bleeding problems.
  • You don't need regular blood tests to check the medicine dose, as you do with warfarin.
  • You don't have to watch how much vitamin K you eat or drink, as you do with the anticoagulant warfarin.
What are the risks and side effects?
  • Anticoagulants increase your risk of bleeding problems.
  • Anticoagulants lower your risk of stroke, but you could still have a stroke.
  • 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 an anticoagulant (blood thinner).

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 anticoagulants

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 a blood thinner to help reduce my risk for having a stroke."

— Monty, age 72

"I have a lot of balance problems. They might get better over time, but I do worry about falling. And my doctor says my stroke risk is low. I think I'll stick with aspirin for now."

— Juan, age 67

"I am not overly concerned about bleeding problems from taking a blood thinner, and I'm motivated to follow the instructions to take it as directed."

— 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 an anticoagulant

Reasons not to take an anticoagulant

I worry about my risk of stroke.

My risk of stroke is low.

             
More important
Equally important
More important

I'm confident that I can take an anticoagulant as directed.

I'm worried that I can't take an anticoagulant as directed.

             
More important
Equally important
More important

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.

             
More important
Equally important
More important

My other important reasons:

My other important reasons:

   
             
More important
Equally important
More important

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 an anticoagulant

NOT taking an anticoagulant

             
Leaning toward
Undecided
Leaning toward

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 doesn't have it?

  • Yes
  • No
  • I'm not sure
You're right. Atrial fibrillation increases your risk of stroke, but anticoagulants can reduce that risk.

2. Are anticoagulants safe for everyone to take?

  • Yes
  • No
  • I'm not sure
You're right. Anticoagulants may not be safe for you if you can't control your blood pressure, have stomach bleeding, or drink large amounts of alcohol.

3. Does aspirin work as well as anticoagulants to reduce the risk of stroke?

  • Yes
  • No
  • I'm not sure
You're right. Aspirin doesn't work as well as anticoagulants to reduce your risk of stroke, but it is less likely to cause bleeding problems.

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?

         
Not sure at all
Somewhat sure
Very sure

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.

 
Credits
By Healthwise Staff
Primary Medical Reviewer Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
Specialist Medical Reviewer John M. Miller, MD, FACC - Cardiology, Electrophysiology

References
Citations
  1. Prevention of stroke in patients with atrial fibrillation (2009). Medical Letter on Drugs and Therapeutics, 51(1313): 41.
  2. Antithrombotic drugs (2011). Treatment Guidelines From The Medical Letter, 9(110): 61–66.
  3. Dabigatran etexilate (Pradaxa)—A new oral anticoagulant (2010). Medical Letter on Drugs and Therapeutics, 52(1351): 89–90.
  4. Patel MR, et al. (2011). Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. New England Journal of Medicine, 365(10): 883–891.
  5. Granger CB, et al. (2011). Apixaban versus warfarin in patients with atrial fibrillation. New England Journal of Medicine, 365(11): 981–992.
  6. Fuster V, et al. (2011). 2011 ACCF/AHA/HRS focused update incorporated into the ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation, 123(10): e269–e367.
  7. Paikin JS, Eikelboom JW (2012). Aspirin. Circulation, 125(10): e439–e442.
  8. ACTIVE Investigators (2009). Effect of clopidogrel added to aspirin in patients with atrial fibrillation. New England Journal of Medicine, 360(20): 2066–2078.

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