Understanding Risks of Stroke and Blood Thinners

On average, people with AFib are 5 times more likely to suffer a stroke than those with a normal heartbeat. Strokes related to AFib are often more severe than strokes from other causes.

What does that mean for you or a loved one who has AFib?

When a stroke happens, it tends to be debilitating, often leaving someone fully dependent on others for daily tasks such as dressing, and getting in and out of bed. It might also steal your ability to talk or think clearly.

Stroke is a leading cause of death and disability.

The good news is that blood thinners, also called anticoagulants, can be used to lower the chance of stroke. It is estimated that 3 out of 4 AFib-related strokes can be prevented. This is why health care teams may prescribe a blood thinner for people with AFib.

Blood thinners work by reducing the ability of the blood to clot. But as with all medications, blood thinners have side effects. In preventing blood clots from forming, there is also a higher chance for bleeding in some people. Usually, the bleeding is minor – for example, bruising more easily, or having a nosebleed or cut that takes longer to stop bleeding. However, some bleeding can be serious.

For many patients, the benefits of taking a blood thinner far outweigh the risk of bleeding, according to cardiologists. Even when bleeding does occur, it can usually be managed and is rarely life-threatening.

But research and clinical experience suggest that many patients – and even some clinicians – may worry more about the possibility of uncontrolled bleeding when taking a blood thinner than on the benefit of stroke prevention. It’s important to put these risks in context.

 

Risk is the chance, or likelihood, that something will happen.

For example, people over 80 years of age have a 10% risk of developing AFib. In other words, 10 out of 100 (or 1 in every 10) people in this age group will have AFib.

Using the CHA₂DS₂-VASc risk scoring (a tool used to predict the chances someone with AFib will have a stroke), if you are 75 years or older and have diabetes and high blood pressure, your score is 4. This means your risk of having a stroke in the next year is nearly 5%‐4.8% to be exact. In other words, among people who have these conditions, nearly 5 out of 100 will have a stroke.

A score of 6 ups the risk of stroke to 9.3% – meaning 9 out of 100 people will have a stroke this year.

“In general, most bleeding [related to anticoagulants] can be managed successfully and do not result in irreversible damage (with the exception of intracranial bleeding, which is very rare). In contrast, strokes are more likely to cause disability and can be life-altering, especially for young people,” said Mikhael F. El-Chami, MD, a heart specialist at Emory Healthcare.

While the likelihood of a major bleed from taking an anticoagulant is 2%-3% on average, the risk of stroke is higher. On average, the chance of having a stroke is 5% each year among people with AFib.

The trick is that two people with AFib may have very different risks of stroke and bleeding. That’s why reviewing your risks of both stroke and bleeding and making an informed decision with input from your care team is important.

The good news is there are many options nowadays for blood thinners.

“We have more options than ever,” said Dr. El-Chami. “Some of the newer anticoagulants have lower risks of bleeding compared with warfarin, and all of the newer drugs have a lower risk of bleeding in the brain (intracranial hemorrhage).”

It’s important to talk with your care team about your risk of stroke and bleeding, and your risk for either or both may change over time.

Your health care team may use a number of tools to assess your risk of stroke to help decide whether a blood thinner is right for you.

For example, your health care team may use a formula called the CHA2DS2-VASc to calculate your risk of stroke. This score is based on your age and history of several health issues. Each risk factor is assigned 1 or 2 points, for a maximum score of 9.

Risk Factor	Points
Congestive Heart Failure	1
High Blood Pressure	1
A2: > 75 years old	2
Diabetes (type 2)	1
Stroke or Mini-Stroke	2
Vascular Disease (heart attack, peripheral artery disease)	1
Age: 65-74 years old	1
Sc: Female Sex	1

What your points mean:
                        
0 = Low likelihood of stroke; no blood thinner is likely needed    
1 = Low-moderate risk            
2 or more = High risk

What does this all mean? Your CHA2DS2-VASc score can:

1) Inform treatment decisions about whether you need a blood thinner.

2) Predict your risk of stroke in the next year. For example, if your total score is 3, it means you have a 3.2% chance of having a stroke in the next year. If your score is 6, the risk jumps up to a nearly 10% chance. Talk to your health care team to ask about your risk over time.

Also, there are tools to help you and your care team estimate your bleeding risk. This information will help decide if you can safely take an anticoagulant, which one might be best, and how often you might need follow-up visits. Some people have a higher risk of bleeding due to other health problems or medications they take. Ask your care team to review what increases your chance of bleeding.

If you are at high risk for stroke due to AFib and are unable to take blood thinners because of repeated bleeding or a high risk of bleeding, then a left atrial appendage closure device may be an option for you.

The left atrial appendage is a small, ear-shaped pouch in the heart where blood can collect. Clots that cause strokes in patients with AFib often form there.

By placing an umbrella-like device in the left atrial appendage using a minimally invasive procedure, the chance of stroke from AFib can be lowered without the need for long-term use of blood thinners.  Ask your care team to see if left atrial appendage closure is an option for you.

Your health care team should work with you to choose a blood thinner that’s right for you. What works for some people may not for others. Many factors can influence the choice of blood thinner.

For example:

• Cost. You will want to know what your insurance will cover.
• Restrictions on what you eat. For example, talk with your care team if you are a vegetarian or like leafy greens. Those foods can affect how warfarin works. These foods do not affect the newer anticoagulants. 
• Dosage (the amount). If you have a preference between taking medicine once or twice daily is taken into account. Whatever the frequency, taking your medications as prescribed is essential
• Blood tests. Some patients will need to get blood tests often. People taking warfarin need routine blood testing (usually every 2-3 weeks) to watch how quickly their blood clots and to be sure they stay within a therapeutic range.

Here are some questions to you may want to ask:

• Why do I need to take an anticoagulant?
• How long will I need to take it?
• If I get an ablation for AFib, do I still need anticoagulation?
• If I undergo a cardioversion for AFib, do I still need anticoagulation?
• What are the pros and cons of the different anticoagulants? Which one is best for me?
• What is my personal risk of stroke? How does this compare with my risk of having a serious bleeding event when taking this medicine?
• Will I have any dietary restrictions?
• What is my risk of bleeding?
• How do we make sure I’m not getting too much (if I’m out of therapeutic range)?
• What happens if I fall while taking this medication?
• Do I need to stop doing certain activities when taking this medication?
• What should I pay attention to that would be a sign of bleeding? What are the signs that I might be having serious bleeding?
• Do I need to tell someone if I need dental work done or surgery?
• Are there any medications I should stop taking (for example, aspirin or NSAIDs)?
• Should I let you know if I start bruising more than usual?