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Incidence of Stroke for those with AF taking an Anticoagulant

Cleopatra170710 profile image
37 Replies

According to the Stroke Association over 100,000 people in the UK suffer a stroke each year. A more definitive figure of 113,000 is quoted by the British Geriatric Society. This is a total figure that includes people of all ages, with and without underlying illnesses, etc. The UK population in mid-2019 was estimated by the Office of National Statistics (ONS) to be 66,796,800, therefore the probability of a person having a stroke is 113,000 ÷ 66,796,807 = 0.00169. In percentage terms this is 0.17% or 1.7 people in every 1,000 of the population. However, a number of publications I have read state that for people with atrial fibrillation the likelihood of a stroke increases fivefold, i.e., it is five times greater. This is merely a means of indicating how much more likely those of us with AF are to suffer a stroke than the population at large. In comparative terms it means 1.7 x 5 = 8.5 of us in every 1,000 with AF will suffer one; not a good statistic! Unfortunately, it is unclear whether or not this increase takes into account the use of anticoagulants; is the probability still 5 times greater if you are taking them? I don’t think it is; I seems to remember reading somewhere that the use of anticoagulants reduces the likelihood by about two-thirds, but I can’t find the article again. Perhaps someone on the forum has more data that can confirm or refute this.

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Cleopatra170710
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37 Replies
BobD profile image
BobDVolunteer

The general consensus is that anticogaulation reduces stroke risk by around 70%.which is the figure I have often seen quoted by AFA.

The problem seems to be the large number of asymptomatic people with AF who only discover they have it after the stroke hits them. That and all those people where doctors decide that their stroke risk is too low to bother with anticoagulation. A few years ago I saw some data which suggested that UK was near the bottom of the pile of European countries having at risk patients on anticoagulation and that at least 8000 strokes a year could be avoided if this situation was changed either by attitude modification or screening for AF. This may have improved very slightly more recently. There are many here like me who believe the missuse of the term blood thinner contributes to patient reluctance to take anticoagulation as they think it may them spontaneously bleed which of course it will not.

Remember that AF accounts for 20% of all strokes but around 80% of the least recoverable ones.

Cleopatra170710 profile image
Cleopatra170710 in reply to BobD

Thanks Bob. I believe the benefits of anticoagulants in preventing a stroke greatly outweigh any risks they pose.

in reply to BobD

......and it wasn’t that long ago I tried to increase awareness about the problems caused by using the term “blood thinners” instead of anticoagulants and you would have thought WW3 had started.

Physalis profile image
Physalis in reply to

I'm afraid the cat's out of the bag and you will have difficulty putting it back!

in reply to Physalis

Yes, but with around 50 or so newly diagnosed folk joining the forum a week for help, advice and some assurance, you would have thought we should have been pushing on an open door.

Physalis profile image
Physalis in reply to

Do people use the word coagulant very much in normal life. Even I, knowing it was an anti-coagulant took some time to cotton on to the fact that, if I cut myself, I wouldn't bleed much because the platelets would plug the gap.

in reply to Physalis

Time for my bed.....have a safe week.......

john-boy-92 profile image
john-boy-92 in reply to BobD

I agree. I had a stroke 18 months after an EP said I did not need to take an anticoagulant. The downside of an anticoagulant are procedures that involve bleeding, such as removal of polyps in the colon (especially large flat ones) and, prostate biopsies. I hate not taking anticoagulation before and after.

Brad43 profile image
Brad43

The doctor who started me on Eliquis several years ago said it cuts your stroke risk in half.

momist profile image
momist in reply to Brad43

Figure of speech? Certainly not an accurate statement.

Brad43 profile image
Brad43 in reply to momist

I don't know. I took it literally. He was comparing it to not taking anything. Eliquis' website compares it with taking Warfarin in one study, and aspirin in another. They don't mention any study comparing it to not taking anything.

Its fives times more without anticoagulants. The drugs reduce risk by about 70 percent I.e if AF is your only risk factor for strokes then probably reduces your risk to that of somebody without AF however AF isnt the only cause its greatly influenced by whether you have other risk factors with your AF such as high BP, diabetes etc and how well those are managed.Andy

momist profile image
momist

BobD 's reply includes "AF accounts for 20% of all strokes but around 80% of the least recoverable ones. " That's the scary part!

I wonder if the growth in sport watches with heart monitor facilities has yet moved the statistics on non diagnosed or asymptomatic AF?

BobD profile image
BobDVolunteer in reply to momist

About ten years ago it was thought that about 1 million people in UK were diagnosed with AF and another 1/4 million unknown . The figures are nearer 1.5million diagnosed and 1/2 million unknown at present so the risks of undiganosed AF seem higher.

Now were estimates widely out, are more people developing the condition or is it simple lies damned lies and statistics?

momist profile image
momist in reply to BobD

Statisticians are a much misunderstood bunch. :-)

Peony4575 profile image
Peony4575 in reply to BobD

Probably there are more people getting it . When I was a lass my mother went mad and had a babycham at Christmas, the only time alcohol was in the house. Nowadays most people drink alcohol regularly and anti inflammatory drugs are widely prescribed for osteoarthritis and people generally are heavier so the prevalence of AF increasing is a no brainer

momist profile image
momist in reply to Peony4575

Ooh! Babycham. It can still be found, I think, but is rarely seen. Even ordinary perry is nowadays termed "pear cider" - ouch!. I used to make a snowball from a chilled glass with a sugared rim, one measure of suitable eggnog, and a Babycham shaken and then squirted into it (thumb over the bottle mouth). Frothed up white and golden, and tasted of Christmas. Happy days.

Peony4575 profile image
Peony4575 in reply to momist

Yes snowball was the other thing . Christmas was a treat because you only had certain things at Christmas

Silvasava profile image
Silvasava

I'm one who only found I had AF after a stroke. So lucky it was thrombolised with no after effects and put on anti-coagulants. The AF however is causing problems but that's another story.

hartbeast profile image
hartbeast in reply to Silvasava

This is similar to my experience, Silvasava. Stroke was my first known episode, but every episode since has been highly symptomatic.

MarkS profile image
MarkS

The figures you calculated are a little misleading as they don't take into account age. Strokes are a bit like Covid, the older you are the greater the chance. The risk of a stroke nearly doubles for every decade after your 50's. Also the figures are per year. So it may only be 8.5 per thousand per year, but over 20 years that's 170 per thousand.

Cleopatra170710 profile image
Cleopatra170710 in reply to MarkS

Hi MarkS

I apologise if I have misled anybody. I was merely trying to ascertain whether or not the fivefold increase in the incidence of stroke for people with AF compared with that for the general populace, which is often quoted in medical journals, took into account the preventative effect afforded by direct oral anticoagulants (DOACs).

From the responses of some other forum members, it would appear that it does not include the effect of taking DOACs, which reduce the probability by around 70%. Therefore, referring to my original post, the generalised incidence for those with AF who are taking DOACs is 0.7 x 5 times = 3.5 times, i.e., 3.5 x 1.7 = 5.95 (say 6) in 1000 compared to 8.5 in 1000 for those who are not on DOACs.

I appreciate this calculation is a huge generalisation given that the rate of stroke is dependent on many other factors, such as age, blood pressure, diabetes, etc., and this analysis is therefore far from definitive. It is simply meant as a comparative aid for myself in determining whether or not DOACs provide a statistically significant benefit in terms of preventing a stroke, which I believe they do.

However, I would point out that my calculated incidence for the general populace of 1.69 (rounded to 1.7) in 1000, on which my fivefold increase figure of 8.5 in 1000 for those with AF is based, aligns almost exactly with that presented by Public Health England, which does take age into account:

'Around 85,000 stroke admissions occur each year in England, resulting in an age standardised rate of around 1.7 per 1,000 population in 2015-16, and there are around 32,000 stroke related deaths each year in England, with an age standardised mortality rate of 0.6 per 1,000 population in 2013-15 [PHE].

Sorry again if I misled anyone, it was certainly not my intent.

Cleopatra170710 profile image
Cleopatra170710 in reply to Cleopatra170710

Hi again MarkS

I have made a mistake. Instead of 'by 70%', I read it as 'to 70%'. Thus, referring to my original post, the generalised incidence for those with AF who are taking DOACs should therefore be (1- 0.7) x 5 times = 0.3 x 5 times = 1.5 times, i.e., 1.5 x 1.7 = 2.55 (say 2.6) in 1000 compared to 8.5 in 1000 for those who are not on DOACs.

Sorry for the error, when corrected it makes a big difference.

MarkS profile image
MarkS in reply to Cleopatra170710

Hi Cleopatra, that calculation looks good. You are correct in that a DOAC and well controlled warfarin will reduce stroke risk by 70%.

secondtry profile image
secondtry

MarkS has beaten me too it re the cumulative risk as each year ticks by, looks more and more convincing once you reach 70yo.

As I have so far postponed taking ACs (67yo, AF well controlled), I like to include in this recurring debate the positive reasons for not taking them but I don't have any supportive statistics for these:

Most doctors will agree optimising lifestyle choices will cut the stroke risk substantially; in this situation reacting to a general average of the population would be too pessimistic.

The risk of a bleed both known and unknown (i.e. micro brain bleeds) is avoided.

Side effects of the DOACs will no doubt occur over a longer usage period (my cardiologist has already moved my ACs PIP from Rivaroxaban to Edoxaban due to research in the USA).

So in my view it remains more a personal 'gut' decision rather than a factual one.

Peony4575 profile image
Peony4575 in reply to secondtry

My cardiologist recommends Edixaban also. The one I have requested as a PIP

Cleopatra170710 profile image
Cleopatra170710 in reply to Peony4575

Hi Peony4575Sorry to be thick, but I have seen the acronym PIP used several times on the forum; what does it stand for?

Peony4575 profile image
Peony4575 in reply to Cleopatra170710

Pill in pocket . Usually used as a dose of something to try and stop AF episode like beta blocker or flecanide . In my case I only want to take ACs if and when I have another episode of AF not all the time . That idea was discussed on a different thread

Cleopatra170710 profile image
Cleopatra170710 in reply to Peony4575

Thanks Peony4575

momist profile image
momist in reply to Cleopatra170710

Pill in Pocket. i.e. a remedy to be taken when disaster strikes, usually meaning when just starting AF. Often refers to flecainide, a rhythm control drug which can be regarded as suspect when used on a regular basis, although some tolerate it well for years. The use of an anticoagulant as a PiP when AF starts wouldn't be sufficient reassurance for me though. Many medics will tell you it's not the AF that kills you, but the 'company it keeps'. I know there are theories that blood clots form while the heart is not pumping properly, but with paroxysmal AF, you don't know what is happening while you sleep.

in reply to Peony4575

I'm not sure if DOACs are appropriate for use as a PIP. As I understand it, Afib can cause blood clots to form as the blood stagnates and is vibrated inside the heart. This doesn't happen instantly, and if clots form they may accumulate in the heart or escape and dissolve before causing a problem, or they may dissolve in the heart. If your unlucky they will escape and cause a stroke or heart attack. For example, if you have been in Afib for more than a few hours, you cannot have an electrical cardioversion unless you have been anticoagulated for at least 3 weeks to dissolve any clots, unless it's an emergency. I think this all means that anticoagulation is relatively long term treatment rather than a PIP procedure.

Peony4575 profile image
Peony4575 in reply to

Look at the papers I attached when it was discussed previously . For selected patients it is just as safe. You have to take for a certain number of days depending on the length of the AF episode . I think the cardiologists are probably aware of the things you mentioned

Cleopatra170710 profile image
Cleopatra170710 in reply to secondtry

Hi secondtry

I would agree that taking DOACs or not is a personal decision. I was merely trying to determine whether or not the fivefold increase in the incidence of stroke for people with AF compared with that for the general populace, which is often quoted in medical journals, took into account the preventative effect afforded by DOACs. Apparently, it does not. Please see my response to MarkS.

Regards

TerryB

Over the years, I have been involved in a number of “Pulse Check” days organised by the local hospital in conjunction with our Support Group. These have been held at Shopping Centres, Summer Fairs and other public events (pre Covid of course). On almost all occasions, around 4% of those seen were unaware that they had persistent/permanent AF and they were all over 60 years old. They were advised to see their GP asap to seek medical advice. I believe more recently, surgeries were encouraged to carry out these checks routinely but due to Covid, this has probably fallen by the wayside so the chances are that there are an awful lot of people out there who are totally unaware and at risk......scary!

Physalis profile image
Physalis

I've read through this quickly and I don't think that anyone has said that there are three types of stroke. The most common are the ones caused by a blood clot, then there are those caused by a bleed in the brain. I was more concerned about the second type but I was shown the DOAC figures for each and it was a no-brainer, I took the apixaban.

As a side effect it stopped my attacks of migraine. Hope they'll do more research on that.

There are also TIAs transient ischaemic attacks which are temporary. A friend of mine had one last summer "referred for blood test on 28th, that morning lost the ability to speak, violently sick, managed to sort myself out went for blood test, told my story & she sent me into doctor, suspectedTIA". She's 90 so did quite well I think!

doodle68 profile image
doodle68

I read a report from European Cardiology Society stressing the importance of people who were prescribed Anticoagulants taking them at regular intervals . Apparently some people don't do so putting themselves at risk of a stroke. NOACS in particular with a twice a day dosage only have a short half life and it is essential to stick rigidly to taking a dose every 12 hours for maximum stroke protection. Once a day NOACS should be taken at the same time each day.

Cleopatra170710 profile image
Cleopatra170710

I would have read it had I known it existed; thanks for the link. The information I was trying to illicit was the probability of stroke for those with AF and taking DOACs compared with those not taking them, rather than with people without AF.

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