Most artificial hearts are designed to keep patients alive for months, not decades. The median time a patient lives with a total artificial heart (TAH) before receiving a donor heart transplant is about 4.4 months, though some patients have been supported for years. The longest documented survival on a total artificial heart is 1,374 days, just under 3.8 years.
Typical Duration of Support
A total artificial heart replaces both ventricles entirely. It is almost always used as a “bridge to transplant,” meaning it keeps the patient alive while they wait for a donor heart. In a 20-year study of 196 patients at a single center, survival rates on the device were 72% at one month, 41% at six months, and 34% at one year. Those numbers reflect not just the device’s mechanical limits but also the severity of illness in the patients who receive one. These are people whose hearts have failed so completely that no lesser intervention will work.
The median wait from implantation to transplant is 4.4 months, with a wide range. Some patients receive a donor heart within weeks. Others wait well over two years. A 15-year study of nearly 400 patients found that the length of time on the device did not affect survival after transplant, which is reassuring for patients who end up waiting longer than expected.
The Record: Nearly Four Years
The longest anyone has lived with a total artificial heart is 1,374 days, reported in a patient supported by the CardioWest (now SynCardia) device. That patient eventually received a successful heart transplant. More than 47 patients have survived longer than one year on the SynCardia TAH. These cases demonstrate that the device can mechanically hold up well beyond the typical wait time, even if most patients receive a transplant much sooner.
What Limits the Device’s Lifespan
The device itself can function for years, but complications accumulate over time. Infection is the most persistent threat. In two studies, between 63% and 78% of patients on the SynCardia TAH developed some form of infection during their time on the device. These ranged from respiratory and urinary tract infections to infections along the driveline, the tube that passes through the skin to connect the internal pump to its external power source. That driveline creates a permanent opening in the body, which bacteria can exploit. Early in artificial heart history, infection was the leading cause of death: six out of 15 patients in one of the first Jarvik-7 studies died from it.
Blood clotting is the other major concern with any mechanical heart. When blood flows over synthetic materials, it tends to form clots. Those clots can travel to the brain and cause a stroke. The TAH’s design helps reduce this risk somewhat. It has larger valves and a shorter internal blood path than smaller heart-assist devices, which means blood moves through with less stagnation. Patients still take blood-thinning medications for the entire duration of support.
How It Compares to a Heart Pump (LVAD)
Most people who need mechanical heart support receive a left ventricular assist device, or LVAD, rather than a total artificial heart. An LVAD boosts the pumping power of the existing left ventricle and is smaller, less invasive, and approved for permanent use in patients who will never receive a transplant. LVADs have supported patients for five years or more in some cases.
A total artificial heart is reserved for the sickest patients, those whose heart failure affects both sides of the heart or who have structural problems an LVAD can’t fix, such as dangerous blood clots inside the heart chambers, severe valve disease, or abnormal holes between chambers. Because TAH recipients start out sicker, direct survival comparisons between the two devices can be misleading.
Who Can Receive One
Not every patient in heart failure qualifies. The device is physically large, and the typical candidate is a man with a body surface area greater than 1.8 square meters (roughly corresponding to an average-sized or larger adult male). Women and smaller patients can receive the device, but fitting it into a smaller chest cavity is more complicated. Surgeons now use CT scans and 3D reconstruction of the patient’s chest to virtually “fit” the device before surgery, which helps in borderline cases.
Newer Devices on the Horizon
The Carmat Aeson is a newer bioprosthetic total artificial heart that uses biological tissue on its blood-contacting surfaces rather than pure synthetic material. The goal is to reduce clotting and potentially eliminate the need for aggressive blood thinners. Early clinical cases have been used as a bridge to transplant, with one reported patient receiving a donor heart 26 days after implantation. Surgeons noted the device was remarkably easy to remove during transplant because its smooth surface prevented the scar tissue adhesions that complicate surgery with older devices. Clinical experience remains limited, but the Aeson represents a shift toward designing artificial hearts that interact more naturally with the body’s biology.