A heart made in Zurich
A heart transplant is the only treatment for end-stage heart failure, but donor hearts are in short supply. Artificial hearts suitable for long-term use could present an alternative – and this is precisely what heart specialist Volkmar Falk is working on in the Zurich Heart project, together with Edoardo Mazza and Dimos Poulikakos from ETH Zurich.
Professor Falk, how many of your patients are currently living with an artificial heart?
Volkmar Falk: I have just taken over a hospital in Berlin that runs one of the world’s largest programmes with heart assist devices. We currently have 40 in-patients with one of these systems, and we fit up to 180 systems a year. Many of our patients are suffering from a serious heart condition. Basically, our choices are: an immediate heart transplant, which is rarely possible today given the shortage of organs; treatment to tide the patient over until one comes along; or even long-term treatment with an artificial heart system.
So how long can someone live with an artificial heart?
Falk: There are patients who have lived with one for up to seven years, and in a few cases even longer. Artificial heart systems were really developed as a stop-gap until a donor heart became available. Now some patients manage so well with it that they don’t even want a heart transplant anymore. This is despite all the difficulties that can crop up, such as bleeding complications, blood clots forming in the systems, infections at tube sites, and neurological damage. Technical breakdowns occur, too – with dramatic consequences for the patient.
Professor Poulikakos, you’re an engineer. Do you know any patients with an artificial heart?
Dimos Poulikakos: I’ve had some contact with patients, mainly with Professor Falk, and was taken aback by what I saw. Especially by the fact that the technology really isn’t where it should be in this field. That was a great motivation for me to join the Zurich Heart project.
Professor Mazza, as an engineer, what brought you to the Zurich Heart project?
Edoardo Mazza: I’ve been working on medical projects for some time now, especially with colleagues from the University Hospital. This project is trying to tackle issues that directly relate to our research results. The notion of long-term therapy using an artificial heart pump is socially relevant and a real challenge for research. So the project was a natural choice for us.
Is it a new idea, being able to use an artificial heart for long-term treatment?
Falk: It’s certainly not revolutionary. There are already commercially available mechanical circulation assistance systems that have long been in use. And this is because there aren’t enough donor hearts available, as I mentioned. The great thing about the collaboration on Zurich Heart is that ETH Zurich is the first institution taking up this subject with such impressive expertise in all of the necessary technical fields. In the past, all too often research institutions only addressed individual aspects of the problem, such as energy transfer or surface change. ETH Zurich has the prerequisites in place to develop entirely new concepts as well as to research individual aspects – and to do both at the same high level. Thanks to this expertise, we also have a unique opportunity to set ourselves apart from the companies operating in the sector.
How does the Zurich Heart project tackle these problems?
Poulikakos: From the very beginning of the project, we pursued two main issues that are also intertwined. In the thread I run, we’re trying to improve the existing systems. Problems include haemolysis and thrombosis; we do not really understand the interaction between blood, tissue and the surfaces of the implanted devices, nor the haemodynamics involved. There is barely any reasonably adaptive control systems engineering between the pump and the patient, either. We could make considerable improvements here with the aid of intelligent sensors and control systems algorithms. And there’s the problem of the power supply: we’re looking into whether we can find a wireless solution.
Mazza: In parallel, we considered whether we could actually adopt a very different approach and create something completely new. We call this strand of research “alternative systems”, where we examine whether we could actually work with completely different materials than before. The soft, biomimetic pump we have in mind should approximate the body’s own materials and adapt better to the proportions of the human body, for instance. In other words, we are researching the possibility of “soft machines”. This line of inquiry is highly relevant for modern mechanical engineering. It’s a project with many new questions, for which we also need fundamental research.
How do the different lines of research relate to each other?
Mazza: All the optimisations that Mr Poulikakos mentioned – drive engineering, control systems engineering, sensors – we can also use them very effectively in a soft pump. We also share experimental set-ups and approaches right up to planning the lab and animal tests.
Professor Falk, did you plan on doing something completely new right from the beginning?
Falk: What we see in front of us in the hospital is actually quite shocking: the technology sometimes comes from the 1960s. So we started out by approaching the issue defensively, with the idea of improving the existing technological platform first. But then, in the highly stimulating intellectual atmosphere that ETH Zurich offers, I found partners who think very creatively and don’t immediately bow to conventions. Since then, we’ve developed a prototype for a petrol-powered artificial heart and worked with electromagnetically malleable polymers. Naturally, all the doctors just shake their heads in disbelief at first: that’s just not possible. But it’s precisely this free thinking that generates innovation. Whether it ultimately gets us to our goal remains to be seen. Some ideas will wind up in a dead-end. But the exciting thing is that we can actually go down this road in the first place – with highly motivated researchers.
Did you have to find a common language before you could work together, or were you on the same page from the word go?
Mazza: That’s a good question. The jargon within a specialist field is very efficient. But as soon as you want to be understood outside the discipline, you have to communicate in a completely different way, which takes special skills and a healthy dose of goodwill. Thanks to the tremendous motivation of all the doctors, scientists and engineers involved, however, we managed to overcome the language barriers fairly quickly.
Poulikakos: We were no strangers to working with doctors from other projects. The understanding we had with Professor Falk was outstanding from day one.
Falk: I have always worked very closely with engineers. During my time at the University Hospital Zurich I was delighted have ETH Zurich just on the other side of the road – an institution where the expertise we wanted was right at hand.
Now you’re in Berlin, though, and ETH Zurich is no longer on your doorstep...
Falk: We already have a long joint phase behind us on the project, so we can put up with a bit of distance now. Plus, we put the project in good hands with Hochschulmedizin Zürich (University Medicine Zurich), which guarantees coordination. What’s more, in Berlin we gained a major partner with many patients and a great deal of expertise – a wealth of clinical experience that I will incorporate into the project. And we’ll continue to get more partners on board for individual issues in the future. The Zurich Heart project will keep on developing locally, nationally and internationally. The various locations are bound to be an advantage when it comes to raising competitive external funding as well.
Mazza: I can only agree. Needless to say, the close ties to the University Hospital Zurich remain important to us. Our colleagues there attend our project meetings and Professor Falk’s successor, Francesco Maisano, is enthusiastic about the project. In fact, we’re already planning other projects with him.
Are the results also brought into teaching?
Mazza: The project involves doctoral and other students who are doing projects in the field, and it confronts them with interdisciplinary issues. And we have compiled a list of lectures from various departments that we recommend to them.
Falk: There are various efforts on the part of universities to raise the profile of life sciences in medical education and to develop degree courses in the field of medical engineering or medical IT that are open to both medical students and engineers. A degree in medical engineering would present a tremendous opportunity for many young people, not just as the basis for a scientific career, but also as an attractive qualification for a booming market segment constantly looking for new talent.
Poulikakos: Having a degree path for medical and engineering students would be very interesting, as there are many areas that overlap and one field can benefit from the other’s expertise. But it would be extremely important – and difficult – to give students sufficient knowledge of the basics in both fields within a relatively short space of time. Otherwise, the graduates won’t be capable of tackling the tricky interdisciplinary problems that medical engineering entails.
Let’s return to the Zurich Heart project. When are you expecting results that can be used in practice?
Poulikakos: In one of our sub-projects, which is funded by the Stavros Niarchos Foundation, we’re expecting a product to be translation-ready in three to five years. I believe that the Zurich Heart project’s intrinsic flexibility will allow us to put one innovation after another into practice, whether in collaboration with companies or in another way.
Mazza: One key component of our soft pump is a so-called hybrid membrane. We’re looking for a solution as to how we can integrate an endothelium, i.e. a biological layer, into an artificial system, i.e. a machine, so that the blood flowing through it is exposed to physiologically “normal” conditions. We’re pursuing several paths. In about three years, we want to compare the different solutions in the hope of finding at least one successful approach. Once we have a suitable component, it can be used for our pump and perhaps even other fields of medicine.
The medical field is heavily regulated. How long will it be before you will actually be able to use one of these innovations on your patients, Professor Falk?
Falk: You’ve touched on a major problem there. It takes a shockingly long time before we can actually use something on our patients. Regulators are tightening approval standards for medical products almost every year. So we mustn’t be under the illusion that we’ll be presenting the Zurich heart to the media in a year or two. While we’re bound to be able to celebrate a few breakthroughs, it’s more likely that we will be providing technology to individual third-party suppliers so that it can find its way into practice as quickly as possible, such as good sensor technology. It’s important that we sustain our motivation over the long term – meaning beyond the usual doctoral cycle. And I have seen this commitment again and again in the conversations between the university and ETH Zurich, which is why I’m convinced that Zurich is one of the few places in Europe or even in the world where this might actually be possible.
- Volkmar Falk was director of the Division of Cardiovascular Surgery at the University Hospital Zurich and a professor of heart surgery at the UUniversity of Zurich until September 2014. He is heading up the Zurich Heart project. In October he became a full professor at the Department of Cardiothoracic and Vascular Surgery at Charité in Berlin uand Director of the Department of Cardiothoracic and Vascular Surgery at the German Heart Institute Berlin (DHZB).
- Edoardo Mazza is a full professor of mechanics at ETH Zurich’s Department of Mechanical and Process Engineering. He runs the Alternative Systems research thread in the Zurich Heart project and is studying how soft materials might be used in a future artificial hearts.
- Dimos Poulikakos, a full professor of thermodynamics at ETH Zurich’s Department of Mechanical and Process Engineering, is in charge of system modifications in the Zurich Heart project, with a focus on improving the current support systems.