FRANCE’S ARTIFICIAL HEART: A MACHINE THAT CAN BEAT WITH THE BODY

I have to admit, when I first looked into the French Aeson artificial heart, I found myself thinking about just how quickly the boundary between biology and engineering is disappearing. We are now at a point where engineers are not simply creating machines that mechanically move blood around the body, but are attempting to reproduce some of the behaviour of a living heart. Aeson, developed in France by CARMAT, was designed for people with severe, end-stage biventricular heart failure, where both sides of the heart can no longer provide enough pumping function to sustain the circulation. What particularly caught my attention is that the system is designed to respond to the physiological needs of the person using it. It incorporates sensors and an automatic control system that can alter blood flow according to changes in the patient's condition. In other words, the artificial heart is not simply switched on and left operating at one unchanging output. The system is designed to recognise changes in pressure and filling and adjust its performance accordingly, attempting to reproduce some of the responsiveness we take completely for granted in our own biological hearts.

WHAT MAKES THIS SO INTERESTING TO ME: One of the biggest challenges in creating an artificial organ is that the human body is not simply a collection of mechanical components. Everything is interconnected. When we stand, walk, exercise, rest or change our activity, the cardiovascular system constantly adjusts itself. A normal heart responds automatically, increasing or decreasing cardiac output according to what the body requires. Aeson was designed around this principle of real-time autoregulation. Its pressure sensors and control system allow the device to modify its output in response to changing physiological conditions. I find that extraordinary because we are moving away from the idea of an artificial pump and towards something much closer to an artificial physiological system. It is still a machine, but it is a machine designed to listen to the body and respond to it. Published clinical experience has specifically investigated this autoregulation system in patients receiving Aeson support.

THERE IS ALSO A BIOLOGICAL COMPONENT: Something that I think many people will find fascinating is that this artificial heart is not made entirely from synthetic materials. Aeson incorporates treated bovine pericardial tissue, meaning biological tissue originating from the sac surrounding a cow's heart. There is a very specific reason for this. Whenever blood comes into contact with artificial surfaces, there are complex challenges surrounding haemocompatibility, clot formation and bleeding. Engineers therefore have to consider not only whether a device can mechanically perform the job of the heart, but also how the blood behaves when it comes into contact with the materials inside the device. I think this is a fascinating example of how modern medicine is combining biological material with sophisticated engineering. It is important, however, not to misunderstand this part. The bovine tissue does not mean that Aeson is a conventional organ transplant or that it eliminates the immune rejection issues associated with receiving a human donor heart. Its role is primarily connected with the interaction between the device and circulating blood and the biological environment in which the device operates.

WHAT REALLY SURPRISED ME IS THE POSSIBILITY OF MOBILITY: When most people imagine an artificial heart, they probably picture someone permanently connected to a huge machine in intensive care. Aeson is obviously much more sophisticated than that image suggests. The implanted device is connected to an external power and monitoring system, including batteries, which means that a patient can potentially have considerably more mobility than someone confined to a bedside circulatory support system. For carefully selected patients, that can mean getting out of bed, undergoing rehabilitation, walking and potentially leaving hospital while continuing to receive mechanical support. For someone whose only other realistic option may be waiting for a donor heart, that ability to regain some mobility could be enormously important. It is not simply about keeping the circulation going. It is also about giving the patient an opportunity to recover physically while remaining supported.

THE EARLY HUMAN DATA IS PARTICULARLY INTERESTING: A 2025 report involving 10 extremely ill patients in France and Germany looked at patients who had experienced cardiogenic shock and had initially required extracorporeal life support. Six months after receiving Aeson, nine of the ten patients were alive. Five had subsequently received donor-heart transplants, while four were still being supported by Aeson at the six-month point. The researchers also reported improvement in kidney and liver function in patients who had experienced severe organ dysfunction. The median hospital stay before discharge was reported as 42 days. I think these results are worth paying attention to, but I also think it is important to keep the numbers in perspective. Ten patients is a very small group, and early clinical experience cannot tell us how every patient will respond or establish that an artificial heart can replace transplantation for the wider heart-failure population. What it does show is that this technology has progressed beyond an engineering experiment and has been used to support extremely sick human beings.

AND THIS IS WHERE I THINK THE STORY NEEDS SOME CLARIFICATION: Aeson has not simply made human heart transplantation obsolete. Its established European use has primarily been as a bridge to transplantation. That means the artificial heart can take over the pumping function of the failing ventricles while doctors continue looking for a suitable donor heart. To me, this is perhaps one of the most important aspects of the technology because transplantation has always had one enormous limitation that medicine cannot simply engineer away. You can have an experienced surgical team, an advanced transplant centre, sophisticated intensive care and a patient who desperately needs a new heart, but there still has to be a compatible donor organ available. An artificial heart potentially changes the equation by giving clinicians something that every doctor treating a critically ill patient desperately needs: time. Time for the patient to stabilise, time for other organs to recover, time for rehabilitation and, ultimately, time for a donor heart to become available.

THE SCALE OF DEVELOPMENT IS ALSO REMARKABLE: According to CARMAT's reported figures, 108 Aeson hearts had been implanted by the end of March 2025, following the first human implantation in 2013. The company reported that implantation activity had increased substantially during the preceding 15 months. That means this technology has moved through more than a decade of development, clinical experience and refinement. It is a reminder that what looks like a sudden medical breakthrough to the public is usually the result of many years of engineering, experimentation, regulatory work, surgical experience and learning from every patient who receives the technology.

THERE HAS ALSO BEEN A MAJOR CORPORATE TWIST TO THE STORY: The original CARMAT SA experienced serious financial difficulties and entered judicial proceedings. The business was subsequently transferred to a newly created company, CARMAT SAS, with operations continuing under the new entity from December 1, 2025, while CARMAT SA itself was later placed into judicial liquidation in January 2026. I find this part of the story particularly interesting because it demonstrates something we often forget when discussing medical innovation. A technology can be scientifically fascinating and clinically important while the company developing it can still experience enormous financial and organisational difficulties. Scientific progress and commercial success do not necessarily travel along the same road. The technology itself did not simply disappear because the original corporate structure changed.

THE UNITED STATES IS A DIFFERENT STORY: Aeson has been investigated there through an FDA-authorised feasibility programme rather than being generally available as a commercially marketed artificial heart. A published clinical report described a US patient who received the device and was subsequently supported for several months before receiving a donor heart. This is another important distinction because I think headlines can easily make people believe that an artificial heart is now something that anyone with heart failure can simply receive. That is absolutely not what the evidence shows. This is highly specialised technology for carefully selected patients, requiring major surgery, specialist teams, external power and continuous medical monitoring.

WHEN I LOOK AT THE BIGGER PICTURE, THIS IS WHAT I FIND MOST FASCINATING: For most of human history, once the heart permanently failed, there were very few options. Then medicine developed transplantation. Mechanical circulatory support followed. Now engineers are developing artificial organs that attempt to respond dynamically to the body's changing requirements. We are seeing electronics, hydraulics, sensors, biological tissue and computer-controlled systems being combined inside a device that is implanted into a human chest and asked to perform one of the most fundamental jobs in the entire body. That is an extraordinary achievement, regardless of what ultimately happens with this particular technology.

I DON'T THINK WE SHOULD SAY THAT SCIENCE HAS "SOLVED" HEART FAILURE, BECAUSE IT HASN'T. I think the much more interesting story is that medicine is steadily changing what is considered possible. Aeson is not a replacement for every human heart, it is not currently a universal alternative to transplantation and it remains a highly complex intervention with serious risks and limitations. But for a person whose heart can no longer perform its basic mechanical function, the possibility of having an artificial system take over that work while the person waits for another opportunity is something that would have sounded like science fiction not so long ago.

AND PERHAPS THAT IS THE PART THAT STAYS WITH ME: The most valuable thing an artificial heart may provide is not simply blood flow. It may provide time. Time when the patient's own heart can no longer provide enough. Time while damaged organs recover. Time to rehabilitate. Time for doctors to search for a suitable donor. Time that might otherwise simply not exist. To me, that is the extraordinary part of this story. A machine made from engineering, electronics, hydraulics and biological material, operating inside a human body and attempting to respond to what that body needs. We are entering an era where the question is no longer simply whether we can repair a failing organ. Increasingly, we are asking whether we can temporarily or permanently build something capable of performing its function. I find that development absolutely fascinating, because this is not just about an artificial heart. It is a glimpse of where artificial organs as a whole may eventually take medicine.