ResearchPod

Bionic hearts: Ageing, exercise and mobile monitoring

October 23, 2019 ResearchPod ft Dr Eric Stohr
ResearchPod
Bionic hearts: Ageing, exercise and mobile monitoring
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ResearchPod
Bionic hearts: Ageing, exercise and mobile monitoring
Oct 23, 2019
ResearchPod ft Dr Eric Stohr

Heart disease comes in many shapes and sizes – the most serious cases requiring serious interventions to save the patients life, and none are more serious than a heart transplant. However, transplantation requires the availability of not just a heart, but a closely matched one to fit the body and biology of the recipient. If no donor hearts are available, the new generation of mechanical blood pumps may be able to step up and fill that need. Speaking with us today about their professional and personal experiences with Left Ventricular Assist Devices, or LVAD for short, is Dr Eric Stohr and Steve Griffiths.

The original research is available here.

Show Notes Transcript

Heart disease comes in many shapes and sizes – the most serious cases requiring serious interventions to save the patients life, and none are more serious than a heart transplant. However, transplantation requires the availability of not just a heart, but a closely matched one to fit the body and biology of the recipient. If no donor hearts are available, the new generation of mechanical blood pumps may be able to step up and fill that need. Speaking with us today about their professional and personal experiences with Left Ventricular Assist Devices, or LVAD for short, is Dr Eric Stohr and Steve Griffiths.

The original research is available here.

Will:

[inaudible] Heart disease comes in many shapes and sizes, most serious cases requiring serious interventions to save the patient's life and none are more serious than a heart transplant. However , transplantations require the availability of not just a heart, but a closely matched one to fit to the body and biology of the recipient. If no donor hearts are available, the next generation of mechanical blood pumps may be able to step up and fill that need. Speaking with us today about their professional and personal experiences with left ventricular assist devices, or LVADs for short, is Dr Eric Stohr and Steve Griffiths . Dr Eric Stohr, hello.

Dr Stohr:

Hello. Thank you for having me.

Will:

And your research is on a very specific branch of heart disease and cardiac failure. If you could tell us a little bit of the background to that.

Dr Stohr:

It is indeed. A few years ago I had the fortune to get involved with research in what we call patients with advanced heart failure. So patients who have heart disease but who are still continuing to suffer on the normal medications and therefore require what we would consider advanced treatment.

Will:

And is there any particular type of heart failure that these people are experiencing?

Dr Stohr:

The type of heart failure. Feta typically is what we call the left heart failure. So a heart failure of the left side of the heart, which means simply that the heart is not able to pump as efficiently anymore. It doesn't have the force to move the blood around. Uh , and it often starts on the left side of the heart. That's why it's called left, left heart failure.

Will:

when it comes to a therapy to address this heart failure, is it a case of medication or mechanical intervention?

Dr Stohr:

Absolutely. So historically medications were all we had and this was what was helping people and certainly helping people for some time. For example, following a heart attack, or other types of heart diseases, doctors would prescribe medications they would last and work for a certain period of time. But unfortunately some patients, the health declines and he gets the heart disease gets worse. And in these patients, we indeed have the option these days to implant what we call mechanical devices. So provide a mechanical circulatory support.

:

How long have these been available?

Dr Stohr:

That's a very good question. The first prototypes, and we had the great fortune to sometimes meet some of these , uh, these dinosaurs in science, the shoulders that we stand on, they actually started a long time ago, more than 25 years ago now. Mostly in the U S DeBakey, but also professor Jarvik and others. It took a long time to refine them, hence why they maybe hadn't been as popular. And now I would say in the last 10 years, it has become, at least in some countries, a serious option to help patients.

Will:

Speaking of helping patients, we're also joined today by Steve Griffiths. Steve, if you could tell us maybe a little bit about your personal experience, maybe the first onset of heart disease and then the steps that led you to being involved in Dr Stohr's research.

Steve Griffiths:

Thank you for inviting me here today. Initially, seven years ago, I had a heart attack watching rugby. Didn't know I was having one. Don't watch rugby. It's not good for you, not good for your heart at all. So I ended up going into hospital some 18 hours after I had the heart attack a nd because of this late presentation, it actually damage the muscle of the heart, the hardest split into sort of two basic chambers left and right. The central spine of the heart. That muscle virtually became like a brick wall. There was no play in it whatsoever. So after about a year on medication and being ramped up on sort of the normal, and I say normal in inverted commas, treatments and medications for heart failure, I was gradually going downhill. I couldn't tie my own shoe laces . So having problems getting dressed in the morning, couldn't even put my socks on. I was a sorry state, I couldn't sleep on my back, I couldn't breathe, I was having real problems. So in the end it was decided that I would go up to Queen Elizabeth II Hospital in Birmingham because they don't do this sort of information in Wales to go and see about what the alternatives were to treat to me with just medication for heart failure. I get to Birmingham, I'm kept in for best part of a week, all the tests done blood tests. One of the major tests that they do is they stick a catheter down your jugular vein and they check to see whether the pressures inside your lungs have been affected by your heart failure and whether those pressures are suitable for a donor heart, I. E. a heart transplant. If your heart or if a donor heart is put into your body when your pressures are too high because it's a muscle, it's got muscle memory so it'll remember what its put in. So if you put a donor heart in, then that will remember the pressures that the donor had before, not the pressures that you've got in your a system at the moment.

Will:

I can imagine a mismatch there would be a problem.

Steve Griffiths:

A mismatch there is a great problem. Instantly the heart is rejected. They've wasted a donor heart, which someone has very kindly donated. So I had all the tests. I'm laying on the in the cath lab and I've got this tube down my neck on the doctor is going, Ooh , your pressures are a bit high . You're not suitable for transplant. You too will on. My argument was, well how ill do I have to be? I'm not very well at the moment. He said exactly what I just said with the pressures on the right side of my heart because my right side was trying to compensate for my left side was really causing all the problems. So I'm a tier four little conversation with my wife. I can't have a transplant. So what's my next option please? Just someone fix me. I'm young. I'm 49 I've still got two kids growing up who haven't even gone through college yet. I need to see 'em grow up. Please help me someone. So they said you've got an option. I shouldn't. Oh , fantastic. Let's take it. So what's your option? A left ventricular assisted device. An LVAD. But unfortunately because we live in Wales, I couldn't have the LVAD if I'd have lived over the border in England, they'd have kept me in hospital and an LVAD would have been implanted within a couple of weeks. I have to come back home and they say we've got to apply for funding. I saw, great, someone's going to play God in my life now, so I'm at my lowest ebb. We fill out the forms, the doctors do all this for you. You're just a pawn in the whole scenario, but you've got a chance of life. You've got a chance to keep living and that's what you cling to. So everyone working on my side, trying to get all this through the committees and the Welsh health authority and after two failures, we got it through. So on the third time got a phone call say , yep , you can have an LVAD. Happy days. I was really, really happy and thankfully something was going to get done . It's not an easy operation. It's the same operation to implant an LVAD as it is to do a heart transplant. Its exactly the same operation. We all know what goes wrong sometimes in the general anesthetic, the risk factors are still absolutely huge, but I was given a chance and that's all I ever wanted. I will fight my corner, but give me a chance. That's all I want. All this happened in the sort of November time, the test in to see whether I could go on the transplant list and then I was told in the November, yep, you need an LVAD. Then it came to sort of February and they said, we've got a bed for you, Mr. Griffith. I said, I'm just watching sport, it was a Sunday afternoon, I'm just watching sport at the moment.

Will:

It wasn't the rugby was it? Oh no...

Steve Griffiths:

It was, my beloved Scarlet's were playing. So I was watching the Scarlets play on a Sunday afternoon and all of a sudden, bang, we've got a bed available for you. I said, "well can I watch the end of the game and I'll pop up later on or tomorrow?" "You do that, there won't be a bed available for you". I thought, okay, I want that chance. I'm going up now. So I listened to the Scarlets on the radio on the way up and it got taken up and put in a coronary care unit in Birmingham hospital, where I was pumped full of lots of drugs just to get me able to cope with my heart to sort of be in the best possible shape it could be to have the operation a nd that was... Goodness me. That was five years ago.

Will:

The LVAD thatt you got then is the LVAD you're wearing today?

Steve Griffiths:

I 've not had another one a nd I , yeah, it's exactly the same. It's the Heartmate 2 and it's a fantastic little machine and it's given me everything that I ever hoped it would do and more. It is a, excuse my French, but it's a pain in the bottom to absolutely have in the first instance because it's like, I put it akin to having children again. For those of you who haven't had children, you've got to prepare. I can't go and jump in the shower straight away in the morning. I got batteries, I've got a cable coming out of my stomach, which is got an electric feed going into it. So I'm there thinking, well, I can't just do what I want to do if I need to go to the shops. I just can't walk out and go to the shops. As you've seen, I've come today with a rucksack in that rucksack, are a spare battery, spare controller, for the "What If?" scenario. But I've been given a chance. The Welsh economy has spent a lot of money on me, a lot of clever people up in Birmingham hospital looked after me. I'm not going to waste this opportunity. I've been given the chance. I try and look after myself as best I can. The only problem is I can't exercise too much, hence the shape I am.

Will:

No more stressful games of rugby either.

Steve Griffiths:

No, I don't watch England anymore.

Will:

We'll save the political debate of whether it's worth watching England anytime.. And going back to you, Dr Stohr, the Heartmate II that Steve has, that's the second generation LVAD device, is that right?

Dr Stohr:

It is indeed and it's been a very successful device. Steve is one of more than 26,000 patients who've now been implanted with this device and very much like he has described it is a lifeline for some people. It's maybe a temporary lifeline until they can get a heart transplant. For some people it is the solution that the patient will continue to live with.

Will:

So in a normal heart, blood goes in, blood goes out. Or is it slightly more complicated than that?

Dr Stohr:

Well, it's slightly more complicated than that because all four chambers, the areas of the heart that we have , uh , as as humans they're not the same size or they certainly don't have the same function and they are not built in the same way. We can look at muscle structure and we can see that the largest and certainly the part of the heart that needs to pump the hardest, that has the most difficult job, which is that left side is arranged in a very particular way. The arrangement is often described as a double helix, which simply means that the muscle fibers, a wound, they're not straight in line in parallel to each other. They form a certain pattern that can be likened to anything that is sort of found in nature, that is circular: snails houses or in the galaxy or different hearts that we can find that are not straightly arrange. If that's a word.

Will:

So they are bundled together, they are clenched, that gives them more power for pushing blood around the body?

Dr Stohr:

Yes. So there are certainly bundled, that's a very good way of describing them. Uh , often people also described them as if you squeeze out a towel, if you ring out a towel, it's that kind of arrangement, these bundles. And the efficiency or the purpose is actually not 100% known. Uh , we have some indication through scientific research and uh , trying to explain things that this arrangement might be to create a greater efficiency. For example, our cardiac myocytes are heart cells. They only contract by about 10 to 15%, but the heart ejects about 60%. So it means that the heart muscle, how it's contracts in this wringing motion, twisting motion may be involved in greater efficiency to pump the blood around.

Will:

Are there any compensations in a mechanical device that maybe cover for different functions that a normal heart would cover or that it's maybe stepping in to fill any other gaps?

Speaker 3:

Yes, so it , it does function like a normal heart in a way that it is able to pump what we call the cardiac output. So the amount of blood ejected with every beat, but it doesn't actually have beats . So one of the peculiarities biologically, medically for me as a researcher of great interest is that we could say that Steve sat next to me here, it doesn't have a pulse anymore because the HeartMate two device pumps blood not like a pump intermittently where you get the Holby city, E , R whatever show you watch on TV where you get the beep beep beep. But it is actually what we call continuous flow. So if someone tries to measure Steve's pulse, they will not have a lot of luck because actually the blood is flowing through in a steady stream as opposed to the pulse we normally have.

Will:

Sounds like a fun party trick.

Dr Stohr:

I'm sure. I'm sure it is sometimes, yes.

Will:

Does that offer any advantages to a regular human heart? I f t hat something that maybe just evolution hasn't got around to yet? Are there any other challenges associated with it that are requiring more lifestyle changes for Steve and other patients?

Dr Stohr:

All of the above, really for us, the main thing that stands out as researchers but also our colleagues, the cardiologists and the surgeons who implant these devices, it is first of all amazing to think that we never experience it if we are healthy and when patients like Steve have such an LVAD and the blood flows continues, we still live, which is actually remarkable. First of all, it's actually remarkable that it is possible to live with it. Oxygen still gets delivered to where it needs to get delivered clearly. Unfortunately, there are some patients who develop complications like pretty much with any disease. You don't have to be a heart failure patient if you have high blood pressure or diabetes. There are periods where either a patient doesn't feel very well or some patients do better than others and we call this continuous flow, the lack of a pulse, also lack of pulsatility and it's a word that's used a lot in this field. We say there is little or no pulsatility and we think this can in some patients contribute to some complications

Will:

if it's all right with Steve to maybe discuss what some of these side effects might be, if you've had any firsthand experience or if you just would rather leave the room while we talk about them.

Steve Griffiths:

um, no, I have not many side effects to be honest. I've had a couple of instances. The thing with the heartmate two , which is different to the meet three... The newer version is super duper is all singing, all dancing. The HeartMate two was getting there, but it's not quite, I've had a couple of instances where I've been out with a family having a Chinese meal, reading the menu at the restaurant and all of a sudden I tell the wife , um, my eyesight's gone a bit and all of a sudden I just lost vision in my left eye. And it's all down to the fact that the LVAD produces blood clots. So it mashes the blood, the actual blood cells, forms blood clots and you're on warfarin or any other sort of blood thinners to make sure that these clots aren't disastrous. But one or two get through. So for 10 minutes I couldn't, I didn't know what I'd ordered cause I couldn't read the menu, but my sight came back. And then another time at home , um , I wasn't feeling too good one day and I did actually have a mini stroke or a TIA they call it. So my mouth dropped. I couldn't lift my arms above my head. All the adverts we see on telly . So we called the hospital and they said, are you sure he's having a stroke? And yeah , and the paramedic came out and here in Cardiff, he said, "Oh, I've just read up what you've got, you've got an LVAD, let me take your blood pressure." I said, you won't. I've got no pulse, you're not going to be able to do that. He said, well, what should we do? Do we need to take you in for observation? I , the best thing to do is take me in and give me a CT scan to see where the blood clot has stayed there or whatever. Don't give me an MRI scan cause it'd be like sticking me in a microwave, give me a CT scan, let's see where the blood clot is, whether it's still up there. And in 20 hours my face had sort of returned to normal. As normal as normal can be.

Will:

Was knowing to ask for a CT scan expert advice, or part of any education that you've received?

Steve Griffiths:

after a little bit. Yes, a little bit. I mean it's, you have to take care of yourself. They've spent an awful lot of money on you and it's your response. Well , in my view, it's your responsibility to give it the best possible chance to work. If you want to live, look after yourself. And they've spent a lot of money on me. So I want to live. I want to see my kids grow up as best as they can, as best I can. Um, and I want to see Qales win the world cup, it's never going to happen. But you never know. We live in hope.

Will:

You mentioned the HeartMate three there and you've had the HeartMate two for five plus years now and, Dr Stohr, looking at the kind of the future of LVAD development and clinical trials. We're possibly coming up on some measurable data for the HeartMate three a nd similar devices at this point?

Dr Stohr:

Absolutely. The Heartmate three, although the Heartmate two was a great achievement compared with what the options that were previously available to these patients. The HeartMate three is what we all now consider the current generation and it's, it gives more hope and there are some main reasons for that, which is mostly what Steve has already alluded to, the reduction of the clot forming . And so a thrombus, a clot that forms within the pump as the blood goes through the pump before the pump then feeds it back into the body. This has been reduced significantly. And so the prevalence of stroke or an infarct of the brain , has been reduced very much so from 25% to 10%. Now the doctors and certainly us as researchers and I'm sure the patients as well, 10% is still too high, but it's moving in the right direction. So the combination of patient education, patient feedback, clinical experience research is starting to look like we are having a success and this third generation device seems to be doing better than the previous ones.

Will:

And with all that experience translating out to a global incidence of heart failure, the global numbers of people who are having these devices, how is that affecting life expectancy? How is that affecting the ongoing utility of these devices in the lives of patients being treated with them?

Dr Stohr:

Unfortunately, overall, worldwide, and there was not much difference in what we consider typically westernized countries. It doesn't matter so much whether do you live In the U S or in Europe or in other similar countries... The prevalence, the number of people who are suffering from heart failure like Steve, and this could be for different reasons. Following a heart attack, but even without is increasing rapidly. At the same time, the number of donor hearts available that could help patients is staying the same or potentially in some areas even going down. So these mechanical devices are becoming even more important if we want to help patients like Steve. And actually , uh , I have a personal case in my own family. My aunt also has a HeartMate two. It is expected that if the available organ donor hearts, if the numbers don't increase, that we will implant more and more people. In fact, this is exactly what the statistics have shown over the last 10 years. Every year the surgical implantations those surgeries increase.

Will:

And are there any ongoing international trials that any patients or practitioners out there listening to this, if they want to get involved with the kind of research, these kinds of devices, that they could try and participate in, where would be a good place for them to start?

Dr Stohr:

Well, without, you know , drawing all the patients to, to ourselves a , there are probably multiple ones. It depends on what kind of research. There are many, many different medical centers that will have some research ongoing. I encourage anyone to just Google ELVAD and find some medical centers. We collaborated with New York Presbyterian hospital and Columbia university who have a large program. The U S have large programs, other countries in Europe such as Germany, Spain, Denmark and the UK as well. Countries where there are LVAD programs. In terms of research, there is always research ongoing and certainly research needed and we welcome to hear from any patients if they would like to participate. The most important trial, the MOMENTUM III trial has actually just completed. This does not mean that others will not follow. In fact from this trial, I'm sure will follow the next one so that we learn and improve things more. But this one has actually just concluded very successfully.

Will:

and Steve, from your perspective, if there is anyone out there who is possibly on the waiting list for a heart transplant or is weighing up the options of maybe say watchful waiting in hospital or getting one of these devices installed. Any advice for them?

Steve Griffiths:

Get one the doctor is not going to put you forward for an LVAD cause it doesn't suit everybody. But if he's saying that your choice is an LVAD, to say no to a chance of life just seems ridiculous to me. So take that chance. To go on to what Eric was just talking about with research. There are researchers going on, one funded by the British art foundation into actual living with an LVAD , which will be published well in a couple of years, two, three years. But we're ongoing with that at the moment. And that is via queen Elizabeth hospital in Birmingham and Birmingham university. The team up in Birmingham, which is one of the six transplant centers and LVAD centers in the U K they are actually looking at... A lot of doctors and even scientists and people in the know should we say don't like this term, but they look in whether the LVAD can be used as destination therapy rather than a bridge to transplant. So we are, well not we, I'm not involved in it, but people are looking at the fact that a right to life is possibly going to be an LVAD from nylon and it's there for your lifetime. So it's not there to make sure that you're well enough to have a heart transplant because as Eric rightly said, the heart transplants aren't out there at the moment. Plus the research being done on LVADs, I think someone in Poland actually had a fully implantable LVAD. So there were no leads coming out of his body. There was nothing. He did look a bit, a little bit like a zombie, but it's happening and the soul is holding things back from our point of view. And from what we can see is battery technology because of the heat generated by batteries that makes it really difficult to implant fully an LVAD. But we're getting there, I'm say we, it's the Royal we, but the LVAD society is , there is no such thing as an patient society, but we are very, very happy about it.

Will:

And as a part of the community of patients and people involved in this research, I think you're very well positioned to speak on behalf of them.

Steve Griffiths:

I hope am.

Will:

[Laughter] Is there anything else while we're here that you'd like to mention or direct people's attention to or anything that we've missed?

Dr Stohr:

I think it's just an opportunity to almost repeat what Steve said that people should get in touch. One of the still disadvantages despite growing numbers is the low awareness. So we're very grateful for people listening into these or reading some articles or informing themselves because the number of patients is growing rapidly, but even sometimes medical staff would maybe not know how to deal with a human who doesn't have a pulse, or do have a cable coming out of the stomach, a cable that they don't know. There are other diseases that we're very much familiar with where cables come out of people, but maybe not this one. So an increased awareness and equally also people from the community. There is a growing, loving, wonderful LVAD community. People getting in touch with scientists, doctors, and trying to improve the situation further and the most recent clinical trials, and here is another glimmer of hope, suggest that the patient's survival and the patient health is now also almost approaching one-to-one, the successes of heart transplant. So not only is it an alternative, but in the past it was an alternative, a second best option that you weren't doing as well on as if you had a transplant. Now the two are getting almost the same, and we hope of course, that with our effort and everyone else who's involved, that we will get there in making it the success it deserves.

Will:

Fingers crossed and look forward to hearing that good news sometime soon. Eric, Steve, thank you so much for your time today.