#AF-002 Do I Have to Take a Blood Thinner for A-Fib?

January 2nd, 2014 by

Do I Have to Take a Blood Thinner for A-Fib?

If there is one thing I have learned as a cardiologist specializing in atrial fibrillation (A-Fib) it is that patients do not want to take a blood thinner.  While strokes are a feared complication of A-Fib, many of my patients would rather take their chances than gulp down a blood thinner each day for the rest of their lives.  Are there any other options?

The A-Fib Guidelines Have Changed

Until the most recent A-Fib guidelines came out in 2014, a large percentage of my patients could be safely treated with just a baby aspirin each day to prevent a stroke.  Unfortunately,”expert opinion” has swung too far in the other direction and now almost everyone is indicated to take a blood thinner for the rest of their lives.  This has huge implications, especially for women, as I will describe in this article.

Lisa’s Dilema

Lisa is a very healthy and active 65 year old woman.  She skis vigorously in the winter and competes in mountain bike races in the spring, summer, and fall.  Her passion for life are her skis and her mountain bike.  Lisa also has a history of A-Fib.

Lisa’s A-Fib interfered with her ability to compete in sports.  She had tried flecainide to control her rhythm but that only made things worse.  Frustrated, and with no other good options, she opted for a catheter ablation procedure to rid her of her A-Fib.

Fortunately, her ablation procedure went very well and she has had no further episodes of A-Fib.  She is now back to skiing and and mountain biking.  She is loving life again but she is still on a blood thinner despite her high risk of trauma from skiing or mountain biking.

As dangerous as skiing is, my orthopedic colleagues tell me that they see far more fractures and other serious injuries from mountain biking.  As a mountain biker myself I can readily attest to this.  For example, last summer I went over my front handle bars three times while mountain biking the legendary trails of the Wasatch Mountains in Utah.  Fortunately, I do not take blood thinners.

According to the latest A-Fib guidelines, because Lisa is a woman and she is 65 years old, the guidelines would call for her to be on a blood thinner for the rest of her life.  These guidelines stipulate that a blood thinner is recommended regardless of the fact that she has had a successful ablation procedure with no further recurrences of her A-Fib.

What should she do?  Can the guidelines really be right in her case?

Who should be on a blood thinner for life?

Before we get back to Lisa’s case, we need to back up and review the latest A-Fib guidelines.  Whether or not you should be on a blood thinner for life is determined by your CHADS-VASc score.  It does not matter if your A-Fib comes and goes (paroxysmal), present all of the time (persistent), or whether you have had an ablation.

In the CHADS-VASc scoring system, people can have a score of 0-9.  Lower is better with this scoring system.  Based on your score, here are the recommendations:

CHADS-VASc of 0: No blood thinners of any kind are needed

CHADS-VASc of 1: Blood thinners, aspirin, or nothing could be prescribed

CHADS-VASc of 2-9: Blood thinners for life

How do I know what my CHADS-VASc score is?

If you want to know your CHADS-VASc score there is a simple way to calculate your score.  Here is the scoring system:

C: Congestive heart failure, 1 point

H: High blood pressure, 1 point

A: Age 65, 1 point

D: Diabetes, 1 point

S: Stroke or Mini-Stroke, 2 points

V: Vascular disease (prior heart attack or blockages elsewhere in the body), 1 point

A: Age 75, 1 point (you can have up to 2 points based on age)

S: Sex or female gender, 1 point

As you can see from this scoring system, if you are a woman then a blood thinner for life could be indicated.  Is this really a fair scoring system?

What are my odds of a stroke based on my CHADS-VASc score?

In order to make an educated decision regarding whether or not you should take a blood thinner for the rest of your life, you need to know what the odds of a stroke are.  According to the A-Fib guidelines, here is your annual risk of a stroke based on your CHADS-VASc score.

CHADS-VASc of 0: 0% annual stroke risk

CHADS-VASc of 1: 1% annual stroke risk

CHADS-VASc of 2: 2% annual stroke risk

CHADS-VASc of 3: 3% annual stroke risk

CHADS-VASc of 4: 4% annual stroke risk

CHADS-VASc of 5-9: 7-15% annual stroke risk

What are my odds of a life-threatening bleed on blood thinners?

To weigh the risks versus benefits you need to now know the risk of a life-threatening bleed based on taking a blood thinner.  To simplify this process, the blood thinner with the highest risk of bleeding is warfarin (Coumadin) and the blood thinner with the lowest risk of bleeding is apixaban (Eliquis).

The other FDA approved blood thinners in the U.S., dabigatran (Pradaxa), rivaroxaban (Xarelto), and endoxaban (Lixiana) all have an annual bleeding risk somewhere between warfarin (Coumadin) and apixaban (Eliquis).

In the best study to evaluate the real risk of bleeding with these medications, the ARISTOTLE Trial, the annual risk of life-threatening bleeding in 18,140 patients was 2.13% with apixaban (Eliquis) and 3.09% with warfarin (Coumadin).  To put these numbers in perspective, this means that each year 2 in every 100 patients taking apixaban (Eliquis) and 3 in every 100 patients taking warfarin (Coumadin) may die or be seriously harmed by a bleeding complication.

Can’t I just take aspirin instead of a blood thinner?

With the unavoidable risk of life-threatening bleeding with blood thinners I am frequently asked this question.  Unfortunately, aspirin has not shown any consistent benefit in stroke prevention in medical studies.  Some studies showed it was beneficial while others have not shown any benefit.

While a baby aspirin may seem like a very safe medication, there is still about a 1 in 200 risk each year of a life-threatening bleed from aspirin.  It is for this reason that the role of aspirin was significantly downgraded in the most recent A-Fib guidelines.

Will an ablation decrease my risk of a stroke?

Intuitively it just makes sense that if you can eliminate A-Fib then the risk of a stroke should go way down.  Indeed, this is what we have seen based on our experience at Intermountain Medical Center.

In our landmark study of 37,908 patients, we showed that an A-Fib ablation procedure can dramatically reduce the long-term risk of a stroke!  Regardless of how we analyzed the data, as seen in this subsequent medical study, ablation decreased the long-term risk of a stroke.

While other experienced centers have shown similar findings, as these results have not yet been verified in a multi-center randomized study, they are not yet accepted as fact within the medical community.  It is for this reason that the 2014 A-Fib Guidelines still do not recognize that in the right hands at experienced hospitals, an A-Fib ablation can decrease the long-term risk of stroke.  Thus, with the guidelines as they are currently written, we can’t offer ablation as an alternative to life-long blood thinners.

Are there any other options to avoid life-long blood thinners?

Yes, other options are available.  As 90% of the strokes from A-Fib arise from a pouch in the left atrium (left atrial appendage), this left atrial appendage can be removed or plugged to decrease the risk of a stroke.

Watchman Device

The best studied way to close off the left atrial appendage is the Watchman device.  We have implanted this device in hundreds of patients as part of medical studies at our hospital with excellent results.

It is an overnight procedure and patients go home the next day with no cutting and no stitches.  Also, the Watchman device has been available for years in Europe.  However, at the time of this writing it is still not FDA approved in the U.S.

Lariat Procedure

Another option is the Lariat Procedure.  Once again, this is another overnight procedure with no stitches that closes off the left atrial appendage.  We have also had excellent results with this device at our hospital.

While the FDA mysteriously approved this device, there are no convincing data from multi center trials yet that it actually works as promised.  As data are still lacking, many insurance companies are refusing to pay for this procedure.

The ironic thing is that the Watchman device has been extensively studied in thousands of patients and still is not FDA approved whereas the Lariat procedure was FDA approved with no significant data that it even worked.  Go figure.

Surgical Left Atrial Appendage Excision

For patients who require cardiac surgery for other reasons, surgical left atrial appendage excision can be another viable option.  Interestingly, while surgeons have been cutting off the left atrial appendage in A-Fib patients for decades, this surgical procedure has never been studied in a rigorous manner to see if it even works.

The tricky part with the surgical approach is that, even in the best of hands, surgeons will leave a “stump” of the left atrial appendage in about 1 in 3 patients.  Often this “stump” can be a cause of stroke in A-Fib patients.

Thus, in my patients who have undergone surgical removal of their left atrial appendage, I like to perform a transesophageal echocardiogram to confirm there is no remnant “stump” before stopping their blood thinners.

Do natural blood thinners work?

While many of my patients swear by natural blood thinners, such as nattokinase, fish oil, garlic, or vitamin E, to date there are no data that show that any of these natural products can decrease the risk of A-Fib strokes.  Thus, given the lack of data, I cannot recommend these natural products as a substitute for traditional blood thinners.

However, where patients can get into trouble is when they combine these natural blood thinners with pharmaceutical grade blood thinners such as warfarin (Coumadin), apixaban (Eliquis), etc.  If you take any supplements please make sure your doctors are aware of what you are taking.

Should Lisa take a blood thinner for the rest of her life?

Getting back to Lisa, should she take a blood thinner for the rest of her life?  Her CHADS-VASc score is 2 for female gender and because she is 65 years old.

With a CHADS-VASc score of 2 her annual stroke risk is 2%.  However, her annual life-threatening bleeding risk on apixaban (Eliquis) is also 2% per year.  Seems like a wash, right?

To further complicate the analysis, she did have her A-Fib ablation procedure done at our hospital and we know from our study of nearly 40,000 patients that her long-term stroke risk is now low but definitely not zero.  Is she more at risk from bleeding out while skiing or mountain biking or from an A-Fib stroke?

As she is also concerned about her bleeding risk, on her own she decreased her apixaban (Eliquis) from twice a day to just once daily.  Once again I cannot recommend this approach as it has never been studied and it is an off label use of this medication.

At the end of the day, Lisa is a very intelligent patient who fully understands the blood thinner dilemma that she is in.  I cannot say whether what she has decided to do is right or not because it has never been studied.  Also, patients like Lisa who engage in high risk sporting activities have not been adequately studied in these big clinical trials.

What should I do?

By this point in the article you are probably confused as to whether you should take a blood thinner for your A-Fib or not.  This is why you need to have a very candid discussion with your physician to see if a blood thinner is right for you or not.

The new A-Fib Guidelines recommend that nearly everyone take a blood thinner, especially women.  The key is to clearly know your annual stroke risk, based on your CHADS-VASc score, as well as your annual bleeding risk depending on which blood thinner you are on.  Like almost everything else in medicine, it is a decision you and your physician need to make together in weighing the risks versus benefits.


The decision whether or not to take a blood thinner for life is a huge decision with significant consequences either way.  This is something that you must discuss openly and honestly with your physician.

Please remember that everything I shared in this article is general information.  I never share medical advice.  Moreover, reading  this article does not create a doctor patient relationship.  Also, do not self diagnose or treat based on anything that you have read in this article.