#289 13 Reasons Why CHADS-VASc May Not be the Best for Atrial Fibrillation Stroke Prevention

13 Reasons Why CHADS-VASc May Not Be the Best for Atrial Fibrillation Stroke Prevention

Wouldn’t it be great if we could accurately predict who is most at risk for atrial fibrillation strokes?  Despite the aggressive use of blood thinners in the new CHADS-VASc guidelines, there is no proof yet that stroke rates have gone down.  In this article, I discuss 13 reasons why the CHADS-VASc scoring system may not be the best for atrial fibrillation stroke prevention.

What is CHADS-VASc?

For those readers who may be unfamiliar with the CHADS-VASc scoring system for atrial fibrillation stroke prevention, let me give you a quick primer.  CHADS-VASc is an acronym for some of the stroke risk factors.  Based on how many of these risk factors you have, you can calculate your score.  If your score is one or higher, you are a candidate for life-long blood thinners like warfarin (Coumadin), Pradaxa (dabigatran), Xarelto (rivaroxaban), Eliquis (apixaban), or Savaysa (edoxaban).

To calculate your CHADS-VASc score, you get one point for congestive heart failure, high blood pressure, an age of 65 to 74, diabetes, vascular disease (history of a blockage in any artery), or sex (female gender).  If you have had a stroke or TIA, you get two points.  Likewise, if your age is 75 or older, you also get two points.

This CHADS-VASc scoring system has been the “Bible” for blood thinner use in Europe since 2012 and the US since 2014.  Since 2014, this new CHADS-VASc scoring system has had a huge impact on my atrial fibrillation practice.

How CHADS-VASc Has Changed my Practice

At least two-thirds of my cardiology practice is atrial fibrillation.  Other than the dramatic advances in the field of catheter ablation, the most significant change I have seen in atrial fibrillation management has been the CHADS-VASc scoring system for atrial fibrillation stroke prevention.

The reason why CHADS-VASc has had such a massive impact on my practice is that it requires most of my previously low-risk atrial fibrillation patients to now take blood thinners for the rest of their lives.  Despite all of the blood thinners now being prescribed, I’m not convinced things have improved.  As we have been less than impressed with the CHADS-VASc scoring system, our hospital has created a new scoring system which may be better than CHADS-VASc.

13 Reasons Why CHADS-VASc is Wrong for Atrial Fibrillation Stroke Prevention

The low threshold to start blood thinners with the CHADS-VASc scoring system never really made sense to me.  And here are 13 reasons why it may not be the best for atrial fibrillation stroke prevention.

1.  It Doesn’t Predict the Risk of Blood Clots in the Heart

Fully 90% of atrial fibrillation strokes arise from blood clots in the left atrial appendage of the heart.  Thus, if CHADS-VASc worked, you would expect this scoring system to predict the risk of developing a blood clot in the left atrial appendage of the heart.  Unfortunately, studies show that it doesn’t predict the risk of blood clots in the heart.

2. It Wrongly States that All Women Are Candidates for Blood Thinners

According to CHADS-VASc, all women are candidates for life-long blood thinners. Personally, I don’t think that the female gender should count as an atrial fibrillation stroke risk factor.  While there are some studies suggesting women might be at higher risk of stroke, I can find plenty of other studies arguing the opposite.

3. No Credit is Given for an Ablation

Even if a catheter ablation has eliminated your atrial fibrillation, CHADS-VASc gives you no credit.  Despite many studies showing that successful ablation patients have a very low risk of stroke, this scoring system ignores the evidence.

4. There is No Proof it is Better than the Old Scoring System

You would think that it would take compelling evidence to change a scoring system that determines whether or not you should swallow down a blood thinner for the rest of your life.  Sadly, that wasn’t the case.

This new CHADS-VASc scoring system was determined by retrospective database number crunching.  In other words, there was no definite proof that it was any better than the previous scoring system it replaced.  Even worse is that there are now studies showing that it is not as good as what we previously had.

5. No Credit is Given for the Motivated Patient

Regardless of the study, bad things are much more likely to happen to people who aren’t proactive about their health.  And when it comes to atrial fibrillation stroke prevention, the same holds true.

For the motivated patient who tracks their daily heart rhythm, it just doesn’t make sense to take a blood thinner every day when you may only have atrial fibrillation once or twice a year.  Indeed, at least three small studies (1, 2, 3) have shown that it is safe to only take a blood thinner on an as needed basis for people who are tracking their rhythms.  Despite this mounting evidence, CHADS-VASc gives no credit to the motivated patient.

6. It Ignores Reversible Causes of Atrial Fibrillation

Just because you have one episode of atrial fibrillation doesn’t mean that atrial fibrillation will be a lifelong problem for you.  Indeed, many cases of atrial fibrillation are completely reversible.

For example, drinking too much alcohol or getting pneumonia are both reversible causes of atrial fibrillation.  In other words, sobriety and staying healthy can put atrial fibrillation into remission.

Sadly, CHADS-VASc gives no credit to people with reversible causes of atrial fibrillation.  Even though studies show that blood thinners don’t work very well for reversible causes of atrial fibrillation, once again CHADS-VASc doesn’t consider this.

7. It Overlooks the Brain Microbleed Dementia Risk

I suspect that most cardiologists are unaware of brain microbleeds.  While most brain microbleeds don’t cause any symptoms, the more of them you get, the worse your brain functions.  Indeed, studies show that people on blood thinners may get more of these brain microbleeds than people not taking blood thinners.  And the more brain microbleeds you get, the higher your dementia risk.

8. It Assumes People Aren’t Taking Warfarin Anymore

One of the primary arguments of why everyone should take blood thinners for life with CHADS-VASc is that the new blood thinners are so much safer.  While the new blood thinners are much safer than warfarin, the problem is that warfarin use isn’t declining.

When the new blood thinners were released, we were sure that all of the Coumadin (warfarin) Clinics would go away.  In contrast, the number of patients on warfarin has only increased.

At least 99% of my patients on warfarin would love to take one of the new blood thinners. The only problem is that they can’t afford them. For people on a fixed income, there is no way they can afford the annual $5,000 price tag to take one of these drugs.   And if you can’t afford one of the new blood thinners, then the aggressive blood thinner use called for by the CHADS-VASc scoring system may not make sense.

9. Recommending Blood Thinners for a Score of 1 or Higher is Misguided

According to the CHADS-VASc scoring system, a score of one or higher is an indication for life-long blood thinners.  While some studies may suggest a benefit for the low score of one, others don’t.

For example, one study reports that blood thinners for a CHADS-VASc score of one is misguided.  Another highly credible study argues that the cut off for blood thinners should be at least a score of three.  The bottom line is that we really don’t know what the cut off for lifelong blood thinners should be.  In my mind, a cut off of “two” was an arbitrary decision.

10. It Disregards the Left Atrial Appendage

As 90% of atrial fibrillation strokes arise from the left atrial appendage, why does CHADS-VASc ignore this important structure in your heart?  For example, studies from our hospital show that the bigger your left atrial appendage, the higher your risk of stroke.

Also, the shape of your left atrial appendage matters when it comes to your risk of stroke.  In particular, the chicken wing pattern carries a very low stroke risk.  To find out the size or shape of your left atrial appendage, your cardiologist can quickly order a CT scan of your heart.

Lastly, the better your left atrial appendage contracts, the lower your stroke risk.  How well your left atrial appendage contracts is something that is best determined by a transesophageal echo (TEE).

11. It Dismisses the Type of Atrial Fibrillation You Have

Whether or not your atrial fibrillation is paroxysmal (starts and stops on its own) or persistent (doesn’t terminate on its own), determines your stroke risk.  For example, studies show that persistent atrial fibrillation has about twice the stroke risk of paroxysmal atrial fibrillation.  Sadly, CHADS-VASc completely dismisses this.  Regardless of your atrial fibrillation type, CHADS-VASc doesn’t care.

12. It Assumes Your Atrial Fibrillation Burden Doesn’t Matter

Common sense would tell you that when it comes to your atrial fibrillation stroke risk, being out of rhythm all the time is probably much riskier than only being out of rhythm less than 1% of the time.  And, as you might suspect, studies back this up.  CHADS-VASc, however, doesn’t care.  To the CHADS-VASc score, one brief minute of atrial fibrillation carries the same risk as one year of continuous atrial fibrillation.

13. It Rejects the Health of Your Left Atrium

When it comes to your atrial fibrillation stroke risk, the health of your left atrium also matters.  For example, the more dilated your left atrium, the higher your stroke risk.  Also, the more scar tissue you have in your left atrium also predicts your stroke risk. Once again, CHADS-VASc doesn’t care.  A perfectly healthy left atrium is treated the same way as a massively dilated and scarred up left atrium.

Are there Any Better Scoring Systems?

Given the limitations of the CHADS-VASc scoring system, is there anything else out there?  Yes, other scoring systems have been proposed.  For example, there is the ABC-Stroke system which uses blood tests to help determine your stroke risk.  Other scoring systems include GARFIELD-AF, ATRIA, and the Intermountain (my hospital) scoring system.  None of these alternative scoring systems are perfect either.  If nothing is perfect, what should you do?

The answer is to discuss this with your cardiologist.  Only you and your physician can determine if blood thinners are right for you or not.  And to make this decision, you have to take everything into consideration.

Avoid a Stroke…Read this Disclaimer

If you are on a blood thinner, don’t stop this drug based on anything you have read in this article.  Also, don’t let anything I discussed in this article influence your decision.  Strokes can happen and they usually happen in atrial fibrillation patients who are not taking blood thinners.

I have faith that you and your cardiologist can make the right decision for you.  Because taking a blood thinner is a big decision, look at stroke risk factors beyond those of “CHADS-VASc.”  And if you and your cardiologist do decide to hold off on blood thinners, then I would at least carefully check my pulse twice daily to make sure my heart was still in rhythm.  If my heart ever did go out of rhythm, I would immediately get on a blood thinner.

 

 

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26 Comments
  1. Interesting approach What about the patients that have ICDs that maintain pulse rate and do not have a-fib detectable?

    • Hi Robert,

      You bring up a good point. If you already have an implantable device, like a pacemaker or a defibrillator, most of these devices are capable of detecting atrial fibrillation. For the vast majority of people without one of these devices, other technologies can monitor for atrial fibrillation.

      For example, certain smartwatches can now continuously watch your rhythm. Personally, my favorite is the Kardia Band for the Apple Watch. If you then sign up for the free Apple Heart Study run through Apple and Stanford University, you’ll always have someone monitoring for atrial fibrillation.

      John

  2. Really great article. At 66, female I’m on Coumadin for A-Fib that happens twice a week, or twice a month at best. Would love to take Eliquis, my co-pay is outrageous for Eliquis, have no choice but to take Coumadin. It’s indeed a hassle, as diet has to be watched and dose changes all the time to get my INRs at 2. I was also beset with PVCs recently too. I also have GERD, I have to wonder how much the GERD plays a role in creating PVCs. I’ve made great progress in getting PVCs to minimize by walking 20 min everyday — gave up caffiene and instead of my daily 2 glass of wine, I cut it back to 1 glass. Maybe that will make my GERD happy too 🙂 Thanks for the article

    • Hi Peggy,

      Congratulations on the lifestyle optimization! Yes, PVCs can often be minimized by living the healthiest life possible. Likewise, GERD which can trigger PVCs, can also often be treated by weight loss, elimination of unhealthy foods or foods you may have an allergy to, etc.

      Sorry to hear you are stuck on warfarin for now. The price of Eliquis is really way too high. Hopefully, in a few years, we will have a generic version of these new blood thinners.

      John

  3. Dr. Day,
    We are so excited to know that blood thinners may no longer be a life sentence. That would be wonderful. Great news and certainly makes good sense!

    We tried the cauliflower and lentils dish and loved it. Thank you for sharing the recipe, it was so easy to throw together and no mess.

    Love your blog and podcasts,
    Don and Carol

  4. Hi John,

    Just adding my voice to the enthusiastic chorus. All your articles are highly interesting and most informative, but *this* article has absolutely huge potential. You have my sincere thanks. I’ll be discussing it with my cardiologist this week.

    I’m hoping you will soon be able to convince those that need to be convinced!

    A fellow natto fan …
    Michael

  5. 82 yr old male ASC AO AN repair 2007. Went to see a highly regarded EP in Seattle. Said that ablation for AFL, which I have, might lead to AF which would require a more dangerous ablation that he had not done on someone my age. My cardiologist did not have any problem with my waiting until I was symptomatic for the first proceedure. I currently take Elequis for anti coagulation.

    Is there any procedure/technique on the horizon that would make the second ablation safe for and old geezer in pretty good health? PS: loved your book. Thanks,

  6. Thanks for your honesty and candor. I always enjoy and appreciate you insights and willingness to share helpful information.
    I am a 68 year old female who just had an ablation a couple of weeks ago. I have often wondered about the tyranny of CHADS-VASc score, which puts me on the NOAC-for-life track despite my very good health. Actually I am more afraid of bleeding out than having a stroke, as I lead a very active outdoor lifestyle, biking and gardening, etc. I will not opt out of taking NOACs on my own volition, but will certainly have a heart-to-heart in the next few months with my EP if the ablation proves successful long term.

  7. I have an appointment with you soon and I want to discuss warfarin with you badly. I had an ECHO and a CT recently at either Riverton or Lone Peak (bad memory) on Dr France’s recommendation and I asked for the results to be sent to you also. Lone Peak was the hospital. Also Dr Outtrim (Riverton) has me on a heart monitor for 24 hrs a day for 30 days. (Started last Thursday)

    PS….. I’ll be thinking about a possible toothache all day !!! 😁

    • Hi Colin,

      Thanks for reading! As you know, I am a huge fan of natto (the source of nattokinase). While I have discussed the scientific studies supporting nattokinase as a blood thinner, it probably isn’t strong enough for the higher risk atrial fibrillation patients (and there are no studies yet showing that it works for atrial fibrillation stroke prevention). Stay tuned on this one…

      John

  8. Dear Dr. Day,

    Thank you so much for this informative article re Arial fib and blood thinners. I am 77 years old and have had a-fib for about 5 years. I don’t really feel the condition unless I exercise too much. I am somewhat overweight and see my cardiologist about once every year. I dislike taking any sort of medicine and so I have reduced my Eliquis dosage to 2.5 mg twice daily. I have also had 2 cardio-version attempts which were successful but only a few days.

    I take very little alcohol but I feel that drinks per day at the time that this condition arose was enough to trigger the condition, as well as a medium case of sleep apnea. But I do have a question if that is at all possible. From your experience, should I loose weight (212 lbs 5’7″) and completely refrain from alcohol, have you ever known of a case in which the a-fib condition spontaneously resolved itself ?

    I am aware of the probable impossibility that you would have any time to indulge my curiosity. But I am still very grateful for your article… Every bit helps…

    Thank you,

    John Turcot

    • Hi John,

      Thanks for reading and commenting! In my experience, there is a brief window where lifestyle optimization may reverse atrial fibrillation without drugs or procedures. If you have been out of rhythm for a while then lifestyle optimization often needs to be combined with an ablation if you want any hope of restoring sinus rhythm.

      Alcohol is a powerful atrial fibrillation trigger and contributes to weight gain in many people. This is something you should discuss with your cardiologist. Also, please make sure your cardiologist knows about your Eliquis dose reduction…being out of rhythm all the time increases the stroke risk.

      Hope this helps!

      John

  9. Thank you so much for this post. I have been arguing with my doctors for years about my taking blood thinners forever. I always know when I am in afib as I am highly symptomatic. I have a Linq and a Kardia device on my phone to prove it. I always take start Pradaxa as soon as it starts. I continue treatment anywhere between 3 days and 1week depending upon the duration of episode. I am female, 70 and have hypertension. I have had 2 ablations in the past 4 years. I think the most recent one is holding up very well. I am considering entering the study which compares the Watchman and Amulet. According to recent tests I am a good candidate for either. What is your opinion of LAAO?

    • Hi Susan,

      Left atrial appendage closure is an excellent option…based on the studies so far, left atrial appendage closure probably isn’t as good as blood thinners for stroke prevention. However, you don’t have the bleeding risk so overall it appears to be equivalent to blood thinners. There are many ongoing studies on left atrial appendage closure that will shed further light on this new treatment option.

      All the best,

      John

  10. Great insight Doctor!! I enjoy reading your writings on LinkedIn. What are your thoughts regRding Watchman in relation to ChadsVasc scoring?
    Thanks!
    Mike Minacci

    • Hi Mike,

      Great question. Interestingly, CMS (Medicare) wants to see a CHADS-VASc score of 3 for the Watchman left atrial appendage closure. This raises an interesting point because some studies show that it may be best to wait for anticoagulation until the CHADS-VASc score is 3 or higher. When I look at the stroke and major bleeding risk, clear benefit in my mind doesn’t seem to happen until the CHADS-VASc score gets to 3 (unless there was a prior stroke/TIA).

      Hope this helps!

      JOhn

    • Thank you so much Dr. Day for being so open minded in your approach to managing Afib. I could never understand why I was taking Xeralto daily, when I haven’t had an episode in at least 5 years. After I had a 1/4 inch cut on my finger that bled profusely for 24 hours, I decided to cut back on the med on my own. It terrified me thinking of what would happen to me if I was ever in an accident. I keep close watch on my BP and HR, eat according to yours and Dr. Michael Greger’s guidelines. I walk, do yoga and use a stationary bike. My BMI is 21. I mentioned everytime I saw you and Dr. Bunch that I don’t think I even have Afib anymore. I get, as a retired nurse , that you had to follow the guide lines. With this new info I’m totally looking forward to talking to you about my situation at my appointment in October. Thanks again for all the great info in your emails. It’s a wonderful thing you are doing to help people live happier, healthy lives.

      • Hi Karen,

        Thanks for reaching out! Yes, this is a personal decision between you and your cardiologist…looking forward to discussing your particular situation.

        All the best,

        John