Severe heart failure presents a profound challenge, often leaving individuals with limited options. In these critical circumstances, artificial hearts offer a vital form of life-sustaining mechanical support when the native heart can no longer effectively pump blood. These medical devices have transformed cardiac care, offering patients with end-stage heart disease a chance at extended life and improved well-being.
What Artificial Hearts Are
A Total Artificial Heart (TAH) is a sophisticated device designed to completely replace the function of a failing human heart, including its ventricles and valves. This mechanical pump is surgically implanted into the chest, taking over the crucial task of circulating blood to the lungs and the rest of the body. The TAH ensures continuous blood flow, mimicking the natural heart’s pumping action.
TAHs primarily serve two distinct purposes in modern cardiac medicine. The most common application is as a “bridge to transplant,” where the device sustains a patient until a suitable donor heart becomes available for transplantation. This temporary measure is particularly beneficial for individuals at imminent risk of death from biventricular failure who are awaiting a heart transplant.
The other use for a TAH is “destination therapy,” intended as a permanent solution for patients who are not eligible for a heart transplant due to other medical conditions or advanced age. While Total Artificial Hearts have been explored for destination therapy, Ventricular Assist Devices (VADs) are more commonly approved for this long-term application. Unlike TAHs, VADs only assist one or both ventricles of the existing heart rather than replacing the entire organ.
The SynCardia temporary Total Artificial Heart is currently the only TAH approved in the United States, primarily for bridge-to-transplant use. These devices are typically made from durable and flexible materials like polyurethane.
Factors Influencing Longevity
The duration an individual can live with an artificial heart is influenced by a complex interplay of patient-specific factors, device characteristics, and potential complications. Patient-related elements, such as age, overall health status, and the presence of other medical conditions (comorbidities), play a significant role. For instance, patients with pre-existing kidney failure or those requiring dialysis prior to Total Artificial Heart (TAH) implantation often experience higher mortality rates. A patient’s physiological age, rather than chronological age, is a more valuable indicator of their body’s capacity to adapt to the device and recover from surgery.
The specific type and generation of the artificial heart also impact longevity. Advances in technology have led to more compact, efficient, and reliable devices. For example, newer designs using bioprosthetic blood chamber surfaces aim to reduce the risk of clotting and bleeding, potentially extending the lifespan of the device and patient. The durability of the device’s components and the reliability of its power source are also critical, as the mechanical parts of an artificial heart undergo millions of cycles annually.
Complications represent a significant challenge to long-term survival with an artificial heart. Infection is a common concern, particularly around the driveline where the device connects to external power. While infections are frequent, they are not always fatal. Blood clots (thrombosis) are another serious risk because blood comes into contact with artificial surfaces, which can lead to strokes or device malfunction. Patients with TAHs typically require lifelong anticoagulant medication to mitigate this risk. Bleeding, often exacerbated by these necessary blood-thinning medications, can occur during or after surgery and also poses a serious threat.
Device malfunction or failure, though less common with advancements, can necessitate reoperation or lead to life-threatening situations. Other potential complications include kidney failure, liver failure, and chronic anemia. The quality of ongoing medical management, including diligent monitoring for complications, adherence to treatment plans, and prompt intervention for any issues, is paramount for maximizing a patient’s time with the device. While the average duration a patient lives with a TAH before transplant is typically a few months, some individuals have lived significantly longer. One patient successfully lived for 1,374 days (nearly four years) with a CardioWest Total Artificial Heart before receiving a transplant. Another individual survived over seven years with a Jarvik 2000 heart pump, though this was a ventricular assist device rather than a full artificial heart.
Life with an Artificial Heart
Living with a Total Artificial Heart (TAH) significantly changes a patient’s daily routine and overall quality of life. A primary aspect of device management involves carrying external power sources, typically batteries, and a controller. The TAH connects to these external components via drivelines that exit the body, usually through the abdomen. Patients must learn to manage these connections, including changing or charging batteries and responding to alarms from the controller. This external equipment can be somewhat bulky and noisy, potentially impacting mobility and social interactions.
Despite these considerations, patients with a TAH often experience a significant improvement in their physical health and functional capacity compared to their pre-implantation state. The device effectively pumps blood, restoring circulation and improving the function of vital organs. This renewed physiological stability allows many patients to engage in activities they were previously unable to perform, sometimes even driving or participating in light exercise. The ability to leave the hospital and return home, aided by portable drivers, greatly enhances a patient’s sense of normalcy and independence.
The psychological impact of living with an artificial heart can be profound. Patients may experience a shift in their sense of identity, as a machine replaces their native heart. The absence of a natural heartbeat, especially with continuous-flow devices, can be disorienting. Constant vigilance is required due to the need for device management and the potential for complications. Despite these challenges, many patients express optimism and hope for the future, particularly those awaiting a heart transplant.
Ongoing medical care is an integral part of living with a TAH. Regular medical follow-ups are necessary to monitor the device’s function and the patient’s overall health. Patients must adhere to a strict medication regimen, including anticoagulants to prevent blood clots and medications to prevent infection. Blood tests are routinely performed to ensure correct medication dosages.
Cardiac rehabilitation programs are also recommended to help patients regain strength, improve stamina, and manage their new lifestyle. Support from family, caregivers, and medical teams is crucial in navigating the physical and emotional aspects of life with an artificial heart.