Stroke prevention

[rothwell]

I have read somewhere on this site that 60% of strokes are caused by AF. So are the blood thinners not working in some cases? It would be interesting to know how many of this 60% were taking blood thinners.

[Rellim296]

I've just written the following in answer to another post:

I think all anticoagulants do no more than reduce the risk of a clot forming. They don't eliminate the possibility, and total protection is not available on any of them.

A lot of people with AF are not aware that they have it and are therefore not on anticoagulants. When a stroke or TIA occurs, investigations can reveal a dodgy heartbeat that has probably been the undiagnosed culprit.

[Beancounter Volunteer]

Hi Rothwell

I think the figure is 20% of strokes in the UK, but regretably that percentage is the worst type of stroke. AF is the 3rd most common reason for stroke after High Blood Pressure and Diabetes

Some other statistics if I may,

There is an estimated 1.1 million people in the UK who have AF, and around 250,000 of those are undiagnosed.

AF increases your stroke risk by 5 times at any age.

Of the circa 800,000 people diagnosed, only 58% are on an anticoagulant (and remember before the AFA this was much much lower), and 34% of those diagnosed who have a CHADS2Vasc score of 2 or over are still not anti-coagulated (remember that some can't be due to other conditions)

AF is estimated to cause 12,500 strokes a year, and around 7,000 of those are thought to be preventable (NICE statistics)

So the answer to your question, (and I promise not be be flippant and say none as blood thinners don't exist they are anti-coagulants ) Is that AF is estimated to cause 12,500 strokes a year in the UK and on admission for stroke with AF only 40% of those are anti-coagulated.

Be well

Ian

[BobD Volunteer]

I think there is some confusion about stroke.

AF makes us five times more at risk of stroke. Fact.

AF accounts for 80% of the WORST and least recoverable strokes which account for probably 20% of all stroke. Fact.

If we could improve our rate of anti-coagulating at risk patients in UK we could save 8000 strokes a year. (Government figures.)

The plain facts are that UK is one of the worst countries in Europe for this. There are still many thousands of people out there blissfully unaware that they have AF who are at risk of stroke and many more diagnosed with AF who are not on anti-coagulation. There is no screening system in place to find AF which sadly is more often than not found by accident, at A and E after an event or when the patient has a stroke. This is why AF Association has worked so hard with awareness weeks etc.

Now assuming that a person is diagnose with AF we have a system known as Chads or Chadsvasc to assess stroke risk. It is not perfect but the best we currently have. There will always be some who are deemed at low risk who will have a stroke such is the way of life. Quite a few of us feel that AF should mean anticoagulation full stop but that is not what NICE currently recommend so these few will always fall through the gaps.

Anticoagulation reduces stroke risk by about 70% so again nothing is perfect.

Hope that helps answer your question.

[rothwell in reply to BobD]

Thank you very much for your replies. I am really impressed by your knowledge of the statistics. I have also read that in order for a clot to form one needs to be in AF for a certain length of time. Anyone have any knowledge of this?

[Beancounter Volunteer in reply to rothwell]

I think the truthful answer is no-one knows.

However also truthful is that no-one actually knows how long they have been in AF unless they are symptomatic with it, and even then they could have been having asymptomatic AF for any period of time prior to that.

It's certainly true that the risk is much higher after an ablation or a cardioversion, which is why they often perform a TOE to check for clots prior to these procedures, and why they insist on anti-coagulation in all but emergency cases of cardioversion.

Be well

Ian

[rothwell in reply to Beancounter]

Thank you. I have a fitbit charge hr which monitors my heart rate and I can see a daily graph. I would assume that the rate would either be very high or very erratic if I were in AF.

[Beancounter Volunteer in reply to rothwell]

Hi Rothwell

Sorry neither is correct, and from the Fitbit Forum itself.

"Our trackers aren't able to tell you if you have an irregular heart beat but can provide you with a comprehensive look into your heart rate activity over time."

So you could certainly be in AF, wearing a Fitbit and not know.

Kind regards

Ian

[PeterWh in reply to rothwell]

In addition to what Beancounter you can be in AF without a rise in heart rate so only a device such as a Kardia will tell you is you are in AF (or manually - though that is actually less accurate in some cases).

[BobD Volunteer in reply to rothwell]

I would not agree as there is no real evidence of how long it takes. I do know that stroke risk is not dependent on how long or how often you are in AF although there is anecdotal suggestion that clots may be ejected at the moment of returning to NSR. Basically if you have AF you are at risk- end of as they say. .

[Rellim296 in reply to BobD]

Whilst we should be aware of our increased risk, I do think the feeling of vulnerability can get out of hand. Such dire tales were told to me to encourage me to take warfarin that I used to feel a clot or a fatal bleed would happen tomorrow, if not sooner. As I said above, I was convinced it would be the latter and felt absolutely doomed in every direction, scared by sharp objects, cranberries, spinach, AF, stepping out of the front door.... I wasn't a happy bunny when I joined the forum, but three years of anticoagulation and no catastrophe of any sort have made me feel much less threatened. Yes, we may be at risk, but we don't seem to go down like flies.

[rosyG in reply to rothwell]

I have heard a cardiologist say strokes have happened after 6 minutes of AF- don't know whether the individual had a reveal implant or if this is gathered from studies overall.

One stroke consultant told me ( during a reconfiguration meeting I was at with him) that of the last 9 stroke deaths at his hospital 6 were AF patients.

Anyone who is worried about exaggeration of risk can look at their CHADs Vasc score but also be guided too by their HASBLED score to assess individual bleeding risk.

[IsobelBrown54 in reply to rothwell]

I have been AF free for 15 months now and have lost 10 per cent of my body weight this year, but am still obese. My Bp medication and beta blockers have been reduced to lowest dose and I asked my EP if I could reduce or stop the Xarelto. He was adamant that I must remain on it for life. He said it takes only 15 seconds of AF for a fatal clot to form and that anyone can slip into AF without knowing it. I am a vegetarian who swims a kilometre twice a week and walks twice daily. My BP is low and heart rate between 40 and 55 per min. I worry about haemorage more than clots, but am now too scared to stop the Xarelto. Also worried what may happen if anti coagulant is stopped for a medical procedure, only 15 seconds of Afib is enough to cause a stroke!

[Thomps95 in reply to BobD]

It's more accurate to say: AF can increase the risk of stroke for some, and anticoagulation can reduce stroke risk for some. Beyond that, you are going beyond the "facts" of the most up to date research. I follow this research closely (I have 35 years of experience publishing scientific research, and I do understand the scientific methods and statistical evidence).

Bottom line is that people really need to speak to their EP or cardiologist. Most of the "statistics" floating around are misleading and often plain wrong.

For this reason, I have a problem with people citing stats and declaring them as "facts" - but not providing a link to the research that supports such claims.

The best guide for whether to take anticoagulation is currently the CHAD2VAS2 score. Beyond that, don't listen to scare mongering - and we should all avoid propagating it. The forum should be for support - not guilting and scaring people

[PeterWh in reply to Thomps95]

I would disagree with you that it is scaremongering.

Many medical advances over the years have been picked up by medics and patients because someone notices a pattern or have a haunch or read something which triggers further thoughts. I was told that in the medical world often it can take 5 years or more to get a formal study into something (eg do people stay on anticoagulation for life). There are so many steps to go through to do the initial study and then the same for a further study.

This is true for a study that I am going to be involved with where there are no medications, no risks and it has taken almost 6 months to get the final ticks in the boxes so they can send out the details to those on the trial. All the basis, etc was written 6 months ago.

Then there is the ethical situations where if they believe it does benefit patients does it put patients at risk who are NOT given the treatment (ie the placebo group). So for instance with things like anticoagulation I was told that one of the big issues is that they won't do a trial which withholds anticoagulation from patients who it is believed definitely should be having it because of the risk to the patients themselves. Trying to get patients who totally refuse them is very difficult.

[rothwell in reply to PeterWh]

I have tefused anticoagulants for 3 years ( no replies please that I'm a fool and should be taking them!). I'll do a trial

[Thomps95 in reply to PeterWh]

Yes I agree with everything that you said PeterW, and I know the intention is good. I'm also entirely in favour of anti-coagulation when it is indicated - so we're on the same page in that regard. My point was just that on this forum, it would be nice to avoid dogmatic words like "fact" unless we reference original research. Being a researcher with 30 years of experience and having taught statistical methods for 15 years, I've repeatedly referenced my own observations with links to the meta-analyses and data to support my comments. This literature shows that stroke risk is not increased by 5-fold in a blanket manner. Many doctors / cardiologists get the AF-stroke association wrong (they are not typically trained as researchers, and only a small percentage read original research). In the original study that reported a 5-fold increase in stroke risk, the control group was poorly matched. More carefully controlled studies have confirmed the AF-stroke association, but have also shown that the blanket "5-fold increase" is misleading.

I do understand why doctors propagate the statistic. Stroke prevention is important, and patients usually aren't researchers and don't want to split hairs or contemplate a CHAD2VAS2 score. It's easier to say "5 times the risk" so patients get the message and are likely to comply with anticoagulation treatment. So I understand the motivation - but most people on this forum seem to operate at a level of intellectual curiosity above misleading (and yes, scary) pamphlet slogans. We care about accurate information.

If I decide to get an ablation - I'll be starting my advanced anticoagulation treatment! Wish me luck in making the right decision

[Beancounter Volunteer]

Hi Jo

Thanks for your contribution and may I say a valuable one, you say that this site appears to be very pro anti-coagulation and I think you are right, but that's for several reasons.

The AFA itself is very pro anti-coagulation, and this is their site after all.

And doctors when prescribing treatments have to look at overall risk, and I agree with you this is an imperfect methodology and will not suit every situation or patient, but we live in an imperfect world.

I also agree Haemorrhagic strokes are generally much more severe, but they only account for 15% of all strokes, and risk wise this gets lower as you get older, and actually as you know statistically AF is much more prevalent in the older person (like me)

I also agree that CHADS2VASC is imperfect, once again we can only try and bring in a treatment guideline and this is currently the best we have.

Lastly, which you did not state but I will, we also do not really understand for example the long term effects of NOACs, and I fully understand people's concerns around these. Warfarin has a much better documented long term effects understanding.

So given that we have these contradictory challenges, what should a doctor do? Well, in my opinion, and that of the mainstream medical community, all the statistics have to say he/she needs to recommend anti-coagulation, the risk of a ischaemic stoke outweighs that of a haemorrhagic one, the risk of not anti-coagulating outweighs the risk of not, and the risk of bleed does not outweigh the risk of stroke in most cases.

However is has to be an INDIVIDUAL choice, either pre-existing conditions or knowledge may outweigh the decision to anti-coagulate by the doctor, OR the individual themselves might feel that they don't wish to be anti-coagulated for any reason they please, and we should respect that.

So I agree the choice must be down to an individual alongside their medical advisors.

What I can't agree with, is any individual not understanding the decision they are taking, either due to misinformation (which happens even on this site I regret to say) or being told that the risks are lower than they actually are. And it is around that last sentence that the most vociferous debates on this forum tend to revolve.

But thank you Jo, for your contributions here and all the other posts, I honestly feel it's important that both sides of the debate are put and I think you are a polite, intelligent, perceptive and insightful contributor and I value you.

Be well

Ian

[walker66 in reply to Beancounter]

Hi Beancounter,

I had a stroke which was a clot in 2013, so was put on Clopidogrel 75mg and then had another stroke in January this year which was a bleed. They stopped the Clopidigrel straight away, but then in February the heart failure and af and flutter were diagnosed, so this caused a problem for anti coagulation. Instead, I had a left atrial appendage closure (or plug in the heart as they call it) and now I do not need any anti coagulant drugs apparently!

Regards

Sharon

[rothwell in reply to walker66]

Interesting. I wonder why everyone with AF is not given the option for such a procedure then there would be no necessity for anticoagulants.

[Rellim296]

To some extent, Jo, the forum is a ship blown by the wind of those who contribute. Yes, a lot of people are anticoagulation enthusiasts but the site itself is open for those who want to express alternative views. Some of us have been very reluctant to embrace anticoagulation. I was convinced it would kill me but it hasn't succeeded.

[millie-becca-187]

I am a 48 yr old female, who's taken regular medication for 2 yrs. 'Rivaroxoban 20mg' , bisoprolol 15mg and dioxin 250mcg.

I am symptomatic and on the list for an ablation, which is hopefully taking place next week.

I have just been diagnosed as having had a mild stroke, although nothing showed on the scans the Drs said they are still treating it as a mild stroke.

This came as a shock, as I didn't expect for this to happen. No treatment given, just a follow up appointment in 3 months.

[Thomps95 in reply to millie-becca-187]

Oh no! So sorry. Did you experience any symptoms of stroke such as difficulty speaking or moving your left arm? Was it an ischemic stroke or hemorrhagic? I assume ischemic, in which case your anticoagulation may have saved you from something more serious. It sounds like they expect a complete recovery, which is just great.

[millie-becca-187 in reply to Thomps95]

They didn't really say they just said it was a mild one.

My symptoms were total numbness across the left side of my chest, up into my neck and face, collar bone and top of left arm. The only way I can describe the feeling is as though I'd had a local anaesthetic. It felt that numb. I also felt really unwell and woozy similar to af symptoms. My speech was fine. The numbness lasted a couple of weeks. Have been ok since. Had my ablation yesterday and back in nsr! So feeling a little tender today.

[Thomps95 in reply to millie-becca-187]

Great news

[Lizty]

Hi... my mother had a small stroke at 69 years. She did not have afib or high blood pressure. My memory at the time was that it was a haemorrhagic stroke - but she cannot now remember if that was the case. I have asked her to check her medical records but she hasn't done that yet! Well, she is 90 and a bit forgetful! I was just a little concerned because I am now on anticoagulants......

I don't really know what is the difference between the two types of stroke. Can anyone explain?

[Beancounter Volunteer in reply to Lizty]

Hi Lizty

Haemorrhagic, caused by a bleed usually in the brain

Ischaemic, casued by a clot most often from the heart by not necessarily.

Be well

Ian