Summary
The gap between engineering and medicine is narrowing. Now, as well as using technology to assist with surgery through robotics and virtual reality , we are able to create 'replacement' organs, such as artificial hearts, to extend and improve patients' quality of life. In our latest health innovation story, we look at why artificial hearts are needed, how they work, and the type of patients they work for.
Introduction
Imagine if your heart could no longer do its job. Simple tasks like walking to the local shop would feel impossible. This is the reality for people with heart failure, a condition where the heart muscle is too weak to support the body’s needs.
For decades, the ultimate solution has been a heart transplant. The tragic truth, however, is that someone has to die and donate their organs for a heart to become available and there are far more people in need than there are available donor hearts. Thousands of patients wait on transplant lists for a call that may never come. This shortage highlights the urgent need for effective heart transplant alternatives.
This is where a modern medical marvel offers new hope. A lifesaving bridge for end-stage heart failure can provide a second chance. Artificial hearts are not science fiction and are saving lives today. These precision-engineered pumps can take over the work of a failing heart, bridging the critical transplant gap and redefining the boundary of what is medically possible.
Why we can't just rely on heart transplants
A heart transplant is often called the 'gold standard' for end-stage heart failure, but it’s a solution with a heart breaking catch: scarcity. Every year, over 23 million people around the world suffer from heart failure , but only 6,000 will receive a donor heart. According to Statista (https://www.statista.com): "As of March 31, 2025, there were 308 patients on the active transplant list in the United Kingdom (UK) waiting for a heart transplant". This gap between need and supply means that many people will wait for years, with their health declining all the time. For them it’s a race against time that they might not win without realistic alternatives to a heart transplant.
The problem can be even more complex than just the waiting list. Think of the heart as a two-part pump: right side sends blood to the lungs for oxygen, and the left, more powerful side pushes that oxygen-rich blood out to the body. Sometimes, only one side weakens. But in the most severe cases, known as biventricular failure , both pumps begin to fail. The entire system is breaking down, leading to extreme fatigue, severe shortness of breath, and organ damage from the lack of blood flow.
This distinction is crucial because it narrows the heart replacement options dramatically. A device designed to help just one failing chamber simply isn't enough when the whole engine has seized. For patients with biventricular failure, or for those whose own heart tissue is too damaged to support an assist device, the only viable path forward isn't to patch the old organ. It’s to replace it entirely with a machine built for the job.
What is a total artificial heart? A look inside the machine
When a person’s heart is too damaged to be repaired, a Total Artificial Heart (TAH) can take its place. Instead of thinking of it as a single object, it’s best to imagine the TAH as a three-part system working together to completely replace the function of the failing heart. Two parts live outside the body, while one is implanted inside the chest, creating a permanent connection that gives the patient a new lease on life. This system is designed to fully take over the job of pumping blood through the body.
Inside the chest, where the diseased heart used to be, surgeons place two sophisticated mechanical pumps. These pumps are the core of the TAH, built to mimic the action of the heart’s natural chambers - one side pushes blood to the lungs to get oxygen, and the other sends that oxygenated blood out to the rest of the body. Connecting these internal pumps to their external power source is the driveline, a flexible tube that passes through the skin of the abdomen.
That driveline plugs into the external controller , a small computer about the size of a book that acts as the 'brain' for the system. It monitors the pumps and ensures they beat at the right speed. This controller, along with its batteries, is carried by the patient in a backpack or shoulder bag. While it requires constant management, this portable power source is what allows a patient to leave the hospital and regain their freedom. This complete replacement is a life-saving solution for the most severe cases, but it’s not the only type of mechanical heart support doctors use.
'Helper' vs. 'Replacement': The key difference you need to know
While a total artificial heart is a complete replacement, not every failing heart needs to be removed. Sometimes, the natural heart is just too weak to work effectively on its own but can still function with a powerful boost. This is where a Ventricular Assist Device, or VAD, comes in. If a TAH is like getting a whole new engine for your car, a VAD is like adding a supercharger to help the existing one do its job better. It’s a helper, not a replacement.
The choice between these two forms of mechanical circulatory support depends entirely on which part of the heart is failing. A total artificial heart is typically reserved for when both of the heart’s main pumping chambers have failed beyond repair. But often, only one chamber (usually the powerful left ventricle) is the problem. In these cases, a VAD can be implanted alongside the patient's own heart to take over the heavy lifting for that single, weakened side, restoring healthy blood flow.
Ultimately, the distinction between a total artificial heart vs a VAD is about function. One takes over completely, while the other provides critical support. This difference is essential for doctors when deciding which of these remarkable cardiac assist devices is the right path for a patient. So, what makes someone a candidate for either of these life-altering technologies in the first place?
Who can receive an artificial heart?
Receiving a total artificial heart is not a decision made lightly. The primary candidates for heart replacement surgery are NHS patients who are facing the most severe form of heart disease: end-stage biventricular failure. This means both of the heart's main pumping chambers have failed, and all other medical options (from medication to less invasive support devices) are no longer working. These patients are often critically ill and in hospital, with their bodies struggling from a lack of blood flow, making them too sick to survive the wait for a human heart transplant.
For these critically ill patients, a TAH serves a very specific and vital purpose known as bridge to transplant therapy. The artificial heart isn't intended to be a permanent solution, but rather a life-saving 'bridge' that carries a person over the dangerously long wait for a matching donor heart.
By taking over the work of the failed organ, a Total Artificial Heart can restore normal blood flow, allowing the patient’s other organs to recover and helping them regain strength, making them a better candidate when a donor heart finally becomes available.
Ultimately, the goal is to turn a patient who is too sick for a transplant into one who is well enough to receive it. The TAH buys them that crucial, second chance. This life-saving technology provides precious time, but it also completely changes a person's daily reality.
What is life like with a mechanical heart?
For someone who was recently confined to a hospital bed, life with a total artificial heart (TAH) can feel like a miracle. The return of normal blood flow means a dramatic recovery of energy and strength. Simple activities that were once impossible become achievable again, allowing many patients to leave the hospital and return home. This newfound freedom is profound, offering the ability to participate in daily life, such as:
- Walking the dog
- Cooking a meal
- Attending a family event
This return to normalcy, however, comes with a new set of responsibilities. A TAH is an external system, and patients are tethered to their life-sustaining gear. They wear a backpack or shoulder bag that holds the device controller and batteries, which must be managed and charged diligently. In many ways it is like a smartphone, but with life-or-death consequences if not looked after. Patients learn to sleep while connected to a power console and can never be far from a backup power source.
A key part of this new routine is managing the driveline, the crucial cable that passes through the skin to connect the internal pumps to the external controller. This site requires daily, sterile cleaning to prevent infection, which is a constant and serious risk. This meticulous care becomes a non-negotiable part of the day, a small but vital price for the time the device provides.
Living with a TAH is a unique blend of liberation and vigilance. It restores the body but demands constant attention to the machine keeping it going. While the daily duties are manageable, they represent just one aspect of the new challenges patients face.
The hidden risks and hurdles of artificial hearts
1. Infection
While a TAH restores life-giving blood flow, it also introduces new vulnerabilities. The driveline, essential for powering the device, is its single greatest point of weakness. Our skin is a remarkable, seamless barrier against infection, but the driveline creates a permanent opening, a direct pathway from the outside world into the body. This requires constant vigilance, as the risk of a serious infection is ever-present and is one of the most common and dangerous complications for patients.
2. Clotting
Inside the body, an entirely different challenge emerges. Blood is programmed to clot when it encounters a foreign surface, a natural defence mechanism to stop bleeding. Despite being built from highly advanced materials, a mechanical heart is still an unnatural object. To prevent the body from forming dangerous blood clots on the device, which could then travel to the brain and cause a stroke, patients must take powerful blood-thinning medications for as long as they have the implant.
These two hurdles are the central challenges driving innovations in artificial heart technology. Managing them requires a delicate balance of sterile care, powerful medication, and constant medical oversight. This ongoing balancing act is what ultimately defines a patient’s long-term outcome, directly influencing the answer to the most pressing question: just how long can a person live with a machine for a heart?
How long can you live with a TAH?
The answer to how long you can live with a TAH depends entirely on its purpose. For most patients, the device is a temporary lifeline to 'bridge the gap to a transplant'. It is designed to keep them healthy enough to survive the months, or even years, it might take to find a matching donor heart. In this role, the TAH is a high-stakes waiting game.
Increasingly, however, the TAH is used as a permanent solution for patients who are not eligible for a transplant due to age or other health conditions. This path is known as destination therapy. Here, the device isn’t just a waiting room; it's the final treatment. Remarkable cases have shown this is a viable long-term option, with some patients living for years on a heart device, enabling them to return home and regain a sense of normalcy. However, destination therapy is rare in the UK because the devices for advanced heart failure are not recommended for routine commissioning by NHS England .
Despite these incredible advances, a human heart transplant remains the gold standard for those who qualify. The daily challenges of living with a TAH, from managing the external equipment to the constant risk of infection, mean that a biological heart is still the preferred outcome.
The ultimate dream, therefore, is to create an artificial heart so advanced that the line between a 'bridge' and a 'destination' finally disappears. This might not be too far away if developments continue at their current pace as this story of a heart transplant patient in Australia shows .
The future of the artificial heart: Smaller, smarter, and wireless
What once sounded like science fiction is now a life-saving reality and one of the most critical heart replacement options available today. For thousands, this device isn't just a machine; it is a precious bridge over the agonising wait for a donor organ, granting them the irreplaceable gift of more time.
Looking forward, the next great leaps in artificial heart technology are already in sight. Engineers are racing to miniaturise devices to fit more patients, including women and children. The ultimate goal is even more ambitious: wireless power, which would eliminate the external driveline, giving patients total freedom and dramatically reducing infection risk.
These ongoing heart surgery innovations show us that when faced with our bodies' limits, we can find a way to engineer miracles.
