Main content

Papilloedema; Cardiac death in sport; Diagnosing early miscarriage; Warfarin

What is papilloedema? Also, accuracy of screening for sudden cardiac death in sport, diagnosing early miscarriage in women who bleed in early pregnancy, and the story of Warfarin.

What is Papilloedema? The condition has been in the headlines as an optometrist was found guilty of manslaughter after missing abnormalities in the eyes of an eight year old child. Plus, Margaret McCartney debates the accuracy of screening young people for Sudden Cardiac Death in Sport. How to diagnose early miscarriage in women who are bleeding in early pregnancy? And the serendipitous story of how the anti-clotting agent warfarin was first discovered.

Available now

28 minutes

Programme Transcript - Inside Health

Downloaded from

Ìý

THE ATTACHED TRANSCRIPT WAS TYPED FROM A RECORDING AND NOT COPIED FROM AN ORIGINAL SCRIPT.Ìý BECAUSE OF THE RISK OF MISHEARING AND THE DIFFICULTY IN SOME CASES OF IDENTIFYING INDIVIDUAL SPEAKERS, THE Â鶹ԼÅÄ CANNOT VOUCH FOR ITS COMPLETE ACCURACY.

Ìý

Ìý

INSIDE HEALTH - Papilloedema; Cardiac death in sport; Diagnosing early miscarriage; Warfarin

Ìý

Programme 3.

Ìý

TX:Ìý 19.07.16Ìý 2100-2130

Ìý

PRESENTER:Ìý MARK PORTER

Ìý

PRODUCER:Ìý ERIKA WRIGHT

Ìý

Ìý

Porter

Coming up today:Ìý Miscarriage – I meet one of the driving forces behind the move to improve the accuracy of ultrasound scans in early pregnancy. They may be accurate now, but that wasn’t always the case.

Ìý

Cardiac arrest whilst playing sport – we debate the evidence behind screening for hidden heart problems that can have catastrophic consequences.

Ìý

Clip

This strikes people in their 20s and their teens and these guys lose several decades of life.Ìý Once you have found something that can potentially kill a young individual – and I use the word potentially as opposed to certainly – then as a physician I do have an obligation to pose some of the risks that may be associated with ongoing athletic activity.Ìý

Ìý

Porter

And we continue our happy accident series looking at the impact of serendipity on modern medicine – this week it is the story of warfarin.

Ìý

But first papilloedema -Ìý a condition most of you had probably never heard of until last week, when an optometrist hit the headlines after being found guilty of manslaughter because she missed papilloedema in eight year old Vinnie Barker.

Ìý

Vinnie died five months after the eye test failed to pick up the vital clue to an underlying build-up of pressure within his brain.

Ìý

But putting the details and ramifications of this tragic case aside what exactly is papilloedema, and what should be done about it? Consultant Ophthalmologist Melanie Hingorani works at Moorfield’s Eye Hospital and has a special interest in children’s eye problems.

Ìý

Hingorani

So in papilloedema the pressure has built up inside the skull for all sorts of different reasons and it starts to strangulate the nerve, the optic nerves, the nerves which carry the sight information to the brain at the back of the eye look swollen or raised.Ìý So the flow of fluid back and forth along the nerve gets stopped and fluid and swelling builds up in the nerve.Ìý So when you look at it it looks very raised, it sits up much higher than it should do at the back of the eye and also it can start to undergo some other changes, for instance it can start to go very pink because the blood can’t escape and if it’s really quite bad you start to see little blood spots or haemorrhages, little burst blood vessels, you can see little white spots where the retina becomes unhealthy and you can start to get fluid build-up across the retina as well, so that looks swollen too.Ìý And one of the biggest difficulties is actually judging what’s normal or a funny sort of normal from what’s actually elevated.Ìý So when you look at the back of a lot of people’s eyes actually the optic nerve comes in all sorts of different shapes and sizes - it can be oval, it can be round, it can be a bit wonky, bits of it can look to stick up – all of that can be utterly and completely normal.Ìý And we get lots and lots of referrals, particularly in children, from people who’ve seen something a bit funny at the back of the eye, the family come up absolutely petrified because they’ve usually gone on Google and looked this up, thinking there’s some awful brain tumour and actually it’s just a normal variant.Ìý And you only learn to diagnose that by looking at lots and lots and lots of the back of people’s eyes.

Ìý

Porter

You’re talking about it being raised and one of the thing I think is the problem straightaway is the little device I use for looking in the back of the eye only works in 2D.

Ìý

Hingorani

Yeah that’s really difficult for people who haven’t got the right kit.Ìý So ophthalmologists and in fact most opticians as well would look at the back of the eye with some sort of two-eyed, that is 3D, viewing system, so that when you look at anything at the back of the eye you can judge depth, whether something is elevated or raised or something’s sort of depressed or hollowed.Ìý But most doctors, including GPs and hospital doctors who are not specialists, would use a 2D viewing system, something where they peer with one eye, looks like a fancy sort of torch and they can only see in 2D, so it’s really difficult to tell that the optic nerve sits up.Ìý You can sometimes see other features, such as the burst blood vessels or the edge of the nerve looks blurry but unless the papilloedema is gross it can be really difficult to pick up with a standard instrument.

Ìý

Porter

So once you spot this sign and you’re pretty sure it’s there, whether you be a consultant ophthalmologist, an optometrist or a GP like me, what should happen next?

Ìý

Hingorani

I think you have to have a level of suspicion and you also have to be proportionate as well.Ìý If you really think this is papilloedema, and particularly if the person with it is suffering from the characteristic symptoms of raised intracranial pressure, that really has to be seen quite quickly on the day or within 24 hours.

Ìý

Porter

And those symptoms would be?

Ìý

Hingorani

So the main one is headache and it’s a very particular sort of headache because lots and lots of people have headaches and of course you can’t send everyone up hot foot to the hospital.Ìý The sorts of things you look for are a headache that is worse in the morning, when you wake up, in fact can wake you up.Ìý It gets worse when you cough or strain or bend down.Ìý People can also feel sick or even start vomiting.Ìý Sometimes they can see double vision and sometimes their vision starts to blur and again it’s a funny sort of blurring – it sort of comes and goes and comes and goes over seconds, what’s called visual obscurations.

Ìý

Porter

So if they have the papilloedema on its own, let’s assume they don’t have any symptoms, but you just spot this sign I mean that’s still worrying, that still suggests that they might have raised intracranial pressure for reasons that might vary from a tumour to a build-up of fluid.

Ìý

Hingorani

Absolutely.Ìý And again one’s got to try and think about – oh is one really sure it’s papilloedema or is it just a normal variant, is the patient unwell or not.Ìý It can actually be something that can be referred over a course of a couple of weeks, rather than a couple of days, just depending because most of what we get sent up suspected as papilloedema is in fact normal and we don’t want to overload the system and we don’t want to worry people.Ìý I think what’s not acceptable is to leave it weeks or months and I think also to have the right conversation with the person that you’re referring, not to put the fear of god into them if it’s not appropriate but equally to make them understand it’s serious enough to get a second opinion in a reasonable timeframe.

Ìý

Porter

Ophthalmologist Melanie Hingorani. And if you are curious as to what the back of the eye actually looks like there is a link on the Inside Health page of the Radio 4 website.

Ìý

Another story that made the headlines while we were off air was the surprise retirement of England batsman James Taylor after he was diagnosed with a serious heart abnormality. Sports – particularly at the highest level – can put the heart under a lot of strain.

Ìý

Fine if yours is healthy, but not so good if it has some form of structural weakness or an electrical glitch. Who could forget footballer Fabrice Muamba’s cardiac arrest on pitch during an FA cup tie in 2012? Cases like his are rare but they’re worrying. Which is why an increasing number of participants are being screened for such problems and not just in the upper echelons of sport, but at schools too. But how effective is this type of screening?

Ìý

Sanjay Sharma, is Professor of Cardiology at St Georges London and a leading authority on the subject

Ìý

Sharma

Screening’s very controversial but the reason that it comes about is that 80% of individuals have no symptoms at all to report.Ìý And both the American Heart Association and the European Society of Cardiology endorse screening on the premise that cheap screening can identify athletes who may be at risk and there are several therapeutic options that are available to us to minimise the risk of sudden death.Ìý The precise type of screening varies from one continent to the other.Ìý The Americans propose a health questionnaire pertaining to cardiac symptoms and a family history of premature cardiac disease as well as physical examination.Ìý And the European approach is to add the 12 lead ECG to history and examination.Ìý The European approach is much better, it’ll pick up electrical faults and one must also remember that although the cardiomyopathies are recognised as the leading causes of death 90% of people with a cardiomyopathy also have an abnormal ECG.

Ìý

Porter

So these ECG abnormalities are indicative of an underlying either electrical or structural or functional problem that could cause sudden collapse and cardiac arrest if they’re out on a pitch.

Ìý

Sharma

That’s true.Ìý And we talk about sudden death rate of one in 50,000 but the other thing that I should emphasise is that if we all screened all athletes and all young people that one in 300 people harbours a condition that could potentially kill.Ìý So the aim of screening is not just to pick up that one individual who would die, it’s to encompass all potential preventable deaths.

Ìý

Porter

But if you’re picking up one in 300 abnormalities and yet only one in 50,000 are going on to have a problem how do you know which one of those people with abnormalities – are do you have to assume they’re all at potential risk, is that what makes it controversial?

Ìý

Sharma

It is controversial because firstly the conditions that cause sudden death are relatively rare, even when you’ve got these conditions your risk of an adverse event is relatively low.

Ìý

Porter

What’s the downside for them of picking – maybe something that may never have come to light?Ìý Presumably the first thing is you might stop their athletic careers in their tracks.

Ìý

Sharma

Correct.Ìý I believe that once you have found something that can potentially kill a young individual, and I use the potentially as opposed to certainly, then as physician I do have an obligation to pose some of the risks that may be associated with ongoing athletic activity.

Ìý

Porter

It’s going to put them off isn’t it?

Ìý

Sharma

You’ll be surprised, it should put some off, it doesn’t put everyone off, it really depends at the level of sport that they’re playing.

Ìý

Porter

Well Dr Margaret McCartney’s been listening to that.Ìý Margaret?

Ìý

McCartney

These conditions are very rare.Ìý The tests for them are not entirely accurate, in fact I would say that they’re often quite inaccurate and can either give a false sense of security or more commonly will detect a problem where there actually isn’t one.Ìý And then you go on to what should you do with the result of that there’s a huge amount of controversy around what is the best treatment for this.Ìý And for many people it’s going to be very unclear and will give a burden of treatment to them more of concern or of anxiety or worry about what might happen to them in the future.Ìý And you can’t just say let’s do a quick and simple test, that’s all there is to it.Ìý This is a chain of events being set into motion for many people and you have to know what the bottom line is here.

Ìý

Porter

We’ve had a number of high profile cases recently, with an England cricketer, we’ve had of course Fabrice Muamba, I’m thinking Fabrice Muamba – there’s an example – surely if he was a professional footballer would he not have been – I don’t want to go into his individual case – but would he not have been part of a screening programme?

Ìý

Sharma

He was, he was screened, relatively limited screening, but he was screened.Ìý And he was cleared, as normal, and did go on to have an exercise related sudden cardiac arrest which would support what Margaret says – that there is an issue about the fact that these tests may actually fail to pick up individuals and may cause a false sense of security in some situations.

Ìý

Porter

So who, in your mind, should we be screening, if anyone, for these abnormalities?

Ìý

Sharma

First and fore mostly my personal belief is that screening should not be mandated, we shouldn’t be forcing cardiac screening on anyone but I must also emphasise that our sporting organisations here, the major ones, all mandate screening.Ìý And the reason for mandating is it’s fine saying that sudden cardiac death is rare but this strikes people in their 20s and their teens and these guys lose several decades of life.Ìý I believe that the sort of people that should definitely be screened are those who have symptoms that are suggestive of cardiovascular disease, such as chest tightness on exertion, breathlessness that is disproportionate to the amount of exercise being performed, palpitation, exertional dizziness or loss of consciousness and those who’ve got a family history where a first degree relative has either died prematurely, aged under 40, or has a potentially genetic cardiac condition.Ìý That group of people should be screened.Ìý In all others screening should be available for an athlete that chooses to be tested.

Ìý

Porter

Margaret, does that not make sense?

Ìý

McCartney

No and I’ll tell you why.Ìý And first of all just to take issue with one thing.Ìý I would argue that if someone has symptoms, for example chest pain, loss of consciousness, palpitations with exercise, that’s not screening that person should have, it’s diagnostic testing.Ìý And I would apply the word screening to people that don’t have any symptoms themselves.Ìý So someone who is fit and well, is exercising with no problems and who then subjects themselves to further testing.Ìý And I’m concerned that there’s organisations going into schools just now offering to do these tests on children, sometimes charging money from them and really not making it clear that this test is not approved by the NHS.Ìý And they’re not done on the NHS because the UK National Screening Committee has looked at all the evidence regularly and have basically said that it’s not a good screening test to do, these ECG tests and echocardiograms, ultrasound of the heart if needed are not good enough to adequately prevent these deaths from young people.Ìý And the problem is that the follow up is all done within the NHS, so it does attract resources into this area when the NHS did not start off the chain of events that has ended up with so much NHS care.

Ìý

Porter

Sanjay?

Ìý

Sharma

Not getting into too much of an argument I disagree with most of what Margaret has said.Ìý There are treatments available for preventing sudden cardiac death.Ìý For example, everybody knows that Beta Blockers save lives in long QT syndrome.Ìý It is true to say that screening can generate false positives and there are false negatives, ECG screening will not pick up all cardiac conditions, particularly those affecting the coronary arteries and in inexperienced hands, just like any screening test, the ECG screening has a high false positive rate.Ìý Our situation here is in an expert setting – our false positive rate is anything between 2 and 3%, which I believe is acceptable.Ìý The athlete should be aware that these are not foolproof, they do not protect from sudden cardiac death, that a positive diagnosis has numerous consequences that go outside sport, for example psychological health, mortgages in the future and even potential jobs – posts such as the army and the police force and being a pilot or a train driver will all be affected.

Ìý

Porter

Margaret, as a parent, look at this from a parent’s perspective, if you had a teenager who was a competitive athlete – a footballer or a female rower or whatever – pushing him or herself to the absolute limit would you want to double check that there wasn’t some form of underlying cardiac abnormality?

Ìý

McCartney

I’m an evidence based parent and I’m not going to subject my children to tests and treatments for which there is no quality evidence that this will benefit them.Ìý And you have to know what the bottom line is here – is there good evidence from randomised control trials or even case control trials or even comparative trials that this kind of screening saves lives, there is not.ÌýÌý It is completely different if there was a strong family history or of course if they had symptoms I would take them to their own GP and get that looked at.Ìý But I’d be looking for really good high quality evidence.

Ìý

Porter

Sanjay, do we actually have any evidence that doing this sort of screening, which must have been going on in some sports for a while now, has had any impact on the number of people affected?

Ìý

Sharma

The only decent study there is in the literature is the Italian experience where the Italians have legislation where all young competitive athletes have to be screened annually with a minimum of a health questionnaire, physical examination, ECG and a limited exercise stress test.Ìý And they have shown that their death rates have gone down from 3.6 per 100,000 when the screening was initiated in the early ‘80s to 0.4 per 100,000, which represents a 90% reduction in sudden cardiac death.Ìý Now clearly that wasn’t double blind or a control study because screening was law in Italy so you couldn’t suddenly not screen some athletes and screen others.Ìý But that is the best data that we’ve got, it comes from the Veneto region where there is a systematic registry for recording sudden cardiac death.

Ìý

McCartney

I would argue with that data.Ìý There was a comparative study done with data from America, basically showing that they felt the Italian data was really random variation down to chance more than anything else.Ìý And furthermore when you haven’t done a randomised control trial you can’t work out what actually made the difference and didn’t.Ìý And additionally in the British Medical Journal not very long ago the researchers actually went and asked for the raw data so they could analyse it and peer review it again for themselves and that request was declined, which is a bit of a red flag to me because that’s the only study that has shown benefit, many others have not shown benefit and in fact the Netherlands stopped doing this kind of screening because they found it to be ineffective.

Ìý

Porter

Sanjay, you’ll be very familiar with what’s going on out there at the moment, is there likely to be more evidence to answer this question?

Ìý

Sharma

Firstly, we have refined the way we look at the ECG and there will be a very detailed ECG interpretation guideline document coming out later on this year.Ìý I am a little bit concerned about the evidence base used by our National Screening Committee, I think the work is so out of date, hardly any papers have been cited from the last four or five years, which is where there have been major advances.Ìý I never cite the American and Israeli papers anymore because they are just so poor and I don’t know how they got published, they were never scrutinised properly.Ìý The Italians they’ve actually submitted their latest data for the last 10 years, the hearsay on the street is that they have continued to demonstrate a reduction in deaths but we will see when this paper gets published.

Ìý

Porter

Well perhaps we should have both of you back to discuss the results.Ìý Professor Sanjay Sharma and Dr Margaret McCartney, thank you very much.

Ìý

We have had an email from a listener – who asked to remain anonymous – questioning the accuracy of the tests used to confirm whether a woman has miscarried in early pregnancy.

Ìý

Email - read

Having listened to you talk about false positives in the medical tests I was wondering how accurate scans are when it comes to diagnosing miscarriage.Ìý Can they get it wrong in women who are bleeding in early pregnancy?

Ìý

Well hopefully not today in 2016, but that wasn’t always the case, as I discovered when I met gynaecologist Professor Tom Bourne from Imperial College whose research helped improve how doctors use ultrasound to diagnose miscarriage.

Ìý

Bourne

So there’s two things principally we look at.Ìý There’s the size of the pregnancy sack and there’s also the size of an embryo, if we can actually see one.Ìý And we take the view that if the gestation sack is over a certain size and we can’t see anything inside it then we consider that to be a miscarriage or if we see the embryo’s over a certain size and we can’t see a heartbeat then again we make a diagnose of miscarriage.

Ìý

Porter

At what stage would you be able to see a heartbeat in a developing baby?

Ìý

Bourne

You’d expect to see a heartbeat at about five – five to six weeks.

Ìý

Porter

And when are the majority of these miscarriages occurring?

Ìý

Bourne

About seven weeks maybe.

Ìý

Porter

So as you’re looking at the scan there’s no heartbeat, you’re measuring the gestational sack and the embryo and it doesn’t fit with the criteria, so you pronounce this a miscarriage.

Ìý

Bourne

Yes.

Ìý

Porter

How accurate is that?

Ìý

Bourne

Well I think now it is accurate because guidelines have changed.Ìý But going back historically what happened in 2011 actually there was a review of all the literature and the conclusion of that was that actually perhaps the guidance at that time wasn’t as robust as it should be.Ìý At that time they used a measurement of the gestation sack which is a pregnancy and we’ll say it was 20 millimetres and they used a size of an embryo which was six millimetres.Ìý And when all the evidence was looked at, actually when we examined it, it was based on very few patients, very few women with very large variation.Ìý At exactly the same time as this review was carried out we had also carried out a study and we showed actually that those measurements were associated with the possibility of misdiagnosis, which was quite significant.Ìý Now you know there should be a zero chance of a false positive diagnosis.Ìý So that was in the UK but if you look in the States, where this situation was even worse, so you had the possibility at that time where you could be in America, have a scan, potentially told you had a miscarriage, fly to England, have another scan and be told it wasn’t a miscarriage.Ìý I mean clearly there’s something not quite right when you’re talking about something as fundamental as whether the pregnancy is alive or not.

Ìý

Porter

And this is only a few years ago…

Ìý

Bourne

It was 2011 yeah.

Ìý

Porter

What number of women do you think might have been affected in the UK and I suppose by number of women I mean women who were told they had a miscarriage when they may not have had one?

Ìý

Bourne

I can give you an idea of certainly in America because there’s been a study carried out by a guy called Roy Filly and he came at it saying well if we change the guidance and start coming up with an increased measurement we’re going to have loads more work to do because all these people will have to come back for repeat scans.Ìý And he estimated that in his practice about 12% of women fell into that category which was quite a significant number.Ìý That of course doesn’t mean that they all have a misdiagnosis or that went wrong but there was potential for error.

Ìý

Porter

So here in the UK we’d be talking about hundreds, if not possibly thousands of women might have been given the wrong diagnosis potentially?

Ìý

Bourne

It’s possible.Ìý I also think you have to bear in mind that increasingly the management of miscarriages – watch and wait – so in those cases of course no harm would have been done.Ìý But there was potential for harm and after he published the paper in fairness recognising that the Royal College – not always the fastest – but they reacted very fast and within seven days they changed the guidelines in the UK.Ìý So that’s in the world of medicine as you know very well that’s a very, very fast response.

Ìý

Porter

Doesn’t happen very often.

Ìý

Bourne

They literally put together a meeting of the multidisciplinary team within about a week and said well this has to change immediately.Ìý So it was an extraordinary fast response.

Ìý

Porter

Had anyone questioned this before your research, was it something people were worried about?Ìý I mean why did you go looking?

Ìý

Bourne

Every so often when you work in clinical practice you’d see people coming to see you for a second scan and you’d see – well that’s interesting, they’d had these measurements and actually this pregnancy's okay, something’s not quite right here.Ìý I’m not saying it happened all the time, it happened sometimes.Ìý And also I think there’s a wider issue in medicine – diagnostic test studies, getting the diagnosis right is absolutely critical.Ìý And it was plainly evident, just someone who’s interested in the field, that there was probably quite wide variation in that the data was not based on enough information that you could say these guidelines were going to be robust, as indeed they turned out not to be really.

Ìý

Porter

Well that’s the next obvious question isn’t it, someone listening to this, a woman’s going to obviously be concerned.Ìý I mean how different is the situation today five years later then?

Ìý

Bourne

The Royal College changed the guidance and the new guidance has what we call 100% specificity, which is a kind of fancy way of saying there were no false positive diagnoses.Ìý So essentially based on this evidence if you have a scan and it says the measurement of the sack is a certain size current guidelines, room for errors is tiny.

Ìý

Porter

They can have confidence today that the test is as accurate as it can be?

Ìý

Bourne

Absolutely, yeah, I think now we’re in a very sort of safe situation where the guidance has changed, we have much greater clarity about where these diagnostic criteria are.Ìý So I think it’s very reassuring actually what the position is at the moment.Ìý I think the other thing it’s done is it’s focused attention on miscarriage.Ìý This is actually highlighting the issue and highlighting how much care you have to take when you’re making a diagnosis as important as this. And we have criteria where we’ve got good data to show that it’s very specific with an absolutely miniscule chance of a false positive test result.Ìý Which I think speaking to women who may be listening to this programme I mean I think it’s now very reassuring, it has to be and it is.

Ìý

Porter

Professor Tom Bourne providing, I hope, some comfort for our listener that the diagnosis of miscarriage is now about as accurate as it can be.

Ìý

Time now for our second in our serendipity series where Dr Margaret McCartney and Professor Carl Heneghan discuss happy accidents that have changed the face of medicine. This week it is the discovery of the anti-coagulant – or blood thinner – warfarin.

Ìý

McCartney

This is a story of cows.Ìý So in the 1920s on the prairies of Canada and North America healthy cattle were dying of internal bleeding and this was a complete disaster, it was after the Great Depression, people had no money and their source of income and food was basically dying on them. And there was an observation that sweet clover hay was associated with the most bleeding, especially when the climate was damp, so when there’d been a lot of rain the sweet clover hay was damn that’s when the cows seem to die the most.Ìý And it was later discovered that the hay seemed to be infected by moulds.Ìý Mouldy hay would normally have been chucked away but because there was no money it was being used where it might not have been used otherwise.Ìý And they actually called sweet clover disease because they were pretty sure that the sweet clover had something to do with the fact that these cows were dying.Ìý And they also worked out that the disease was reversible.Ìý So if you took away the mouldy hay the cows stopped dying.

Ìý

Porter

So it was definitely something to do with the mouldy hay?

Ìý

McCartney

Well that was really as far as it went until 10 years later when another farmer was at his wit’s end – his cows were dying of this disorder no matter what he seemed to be doing.Ìý And he went to a local agricultural experimental station really looking for help.Ìý And he took with him a can of unclotted blood from his cows, saying look the blood’s not clotting, something’s going on, what can I do, please help me.Ìý Now there were two local vets – Schofield and Roderick – and those two basically worked out what was going on.Ìý There was a substance within that mouldy sweet clover that was causing the blood not to clot.Ìý They found it to be natural coumarin and it was being oxidised in the mouldy damp hay to a compound that basically meant that blood couldn’t clot.Ìý And that was later then found to be something that worked in mousetraps to kill rats because it would stop the rats and the mouse blood from clotting and that was a great invention if you had lots of mice and rats running around, that would kill them off for sure.

Ìý

Porter

So Carl we’ve got this discovery of an anti-clotting compound but it’s still not made the jump to humans.

Ìý

Heneghan

What happened is in 1951 a US army inductee unsuccessfully attempted suicide with the rat poison and actually ended up being admitted to hospital.Ìý And one of the issues there is he needed to be treated with vitamin K, which was known as a specific antidote.Ìý I don’t quite know how they knew that because it took a further 20 years until they understood the exact mechanism.Ìý And it was that realisation that actually this rat poison did something really important to the blood making it not so sticky, if you like.Ìý And then they moved very quickly there to the clinical application.

Ìý

Porter

It is interesting though, still as a GP, whenever you mention warfarin people still say you’re going to put me on rat poison doctor.

Ìý

Heneghan

Yeah that’s exactly right, I think that’s how people perceive it actually and that is a widely held story.Ìý And there are a couple of really interesting areas that warfarin has been really influential.Ìý The first is in what we call blood clots which occur in the leg, that’s a deep vein thrombosis, if they occur in the lung that’s a pulmonary embolism.Ìý They have been an important active treatment for preventing them.Ìý And secondly is in a treatment called atrial fibrillation where the heart starts to beat irregularly really fast and can send blood clots round the body and really increase your risk of stroke from one of these blood clots and it’s had a very important effect there.

Ìý

Porter

And until warfarin was discovered did we have a way of treating the clots associated with these diseases?

Ìý

McCartney

Basically not, there wasn’t a good oral tablet treatment that could be given with the same effectiveness at all.Ìý So this was a real breakthrough and something that could actually be used in humans as well.Ìý I think when it went through the 1940s it was something that was treated as something with only side effects and those side effects were the only thing it was good for until it was actually realised well actually you could use this in a smaller dose and the side effect, the thinning of the blood, might actually prove to be a benefit.Ìý And in 1955 it was actually given to President Eisenhower after he had a myocardial infarction and when publicity about that grew it started to become into far wider use.

Ìý

Heneghan

This is a really common treatment, we’re talking about a million people potentially have atrial fibrillation in the UK alone.Ìý And so there are lots of people out there who will understand warfarin, understand atrial fibrillation and probably at some time have been on the internet and have come across the rat poisoning story.

Ìý

Porter

Carl Heneghan and Margaret McCartney, who will be back with more tales of the unexpected later in the series.

Ìý

Just time to tell you about next week when we will be visiting a new one stop clinic for headaches. As well as questioning why rehabilitation therapy is routinely used to help people find their feet after a heart attack, but not for those recovering from cancer.

Ìý

ENDS

Broadcasts

  • Tue 19 Jul 2016 21:00
  • Wed 20 Jul 2016 15:30

Discover more health facts with The Open University

Can you detect health fact from fiction?

Podcast