The artificial heart represents a major advancement in sustaining life for individuals facing end-stage heart failure. This technology is a lifeline for patients whose native heart function can no longer pump enough blood to meet the body’s needs. Examining the lifespan of an artificial heart requires understanding its mechanical design, the biological environment it operates within, and the clinical role it is intended to fill.
Total Artificial Hearts Versus Assist Devices
The term “artificial heart” applies to two distinct types of mechanical circulatory support devices. A Total Artificial Heart (TAH) is designed to fully replace the native heart, requiring the removal of both diseased ventricles. This device must take on the complete mechanical load of circulating blood throughout the body.
Ventricular Assist Devices (VADs), by contrast, are partial support systems, most commonly Left Ventricular Assist Devices (LVADs). An LVAD is implanted alongside the patient’s existing heart, providing pumping assistance to only the left ventricle. The longevity discussion for a true mechanical replacement focuses on the TAH, as it bears the entire burden of cardiac function.
Current Durability Expectations
The current clinical reality for the most widely available Total Artificial Heart (TAH) is that it is primarily used as a temporary measure. It is approved for use as a “bridge to transplant,” supporting the patient until a suitable donor heart becomes available. Patients typically live with the device for an average of 90 to 120 days while awaiting transplantation, though this duration is highly variable.
However, the longest reported survival for a patient living with an approved TAH exceeded four years, demonstrating the device’s potential for extended support. The mechanical durability goal for next-generation TAH models, currently in development, is significantly longer. Some newer designs are aiming for a functional lifespan of 10 to 20 years, shifting the focus toward “destination therapy.”
Primary Limitations on Device Lifespan
The lifespan of a Total Artificial Heart is limited by both mechanical wear and severe biological complications. Available pulsatile TAH models mimic the beating action of a natural heart, relying on internal diaphragms that flex repeatedly. This leads to material fatigue and eventual mechanical failure. Since the TAH completely replaces the native heart, mechanical failure is synonymous with immediate cardiac arrest.
The biological environment within the body poses significant challenges to the device’s long-term viability. All mechanical circulatory support devices require a line that passes through the skin to connect to an external power source. This percutaneous connection creates a permanent pathway for bacteria, leading to a high risk of device-related infections that are difficult to treat.
Furthermore, the non-biological surfaces of the pump mechanism interact constantly with the blood, increasing the risk of clot formation, or thromboembolism. To mitigate the risk of stroke, patients must adhere to a complex and aggressive anticoagulation regimen. This necessary use of blood thinners carries its own risk of major bleeding complications, establishing a difficult balance.
Clinical Strategies Following Device Failure
The mechanical and biological limitations of the TAH influence its primary role in patient care, categorized into two main strategies. The most common application is “Bridge to Transplant” (BTT), where the device is implanted to keep the patient alive until a donor heart can be secured. The artificial heart is intended to function only for the duration of the waiting period in the BTT strategy.
The alternative strategy, known as “Destination Therapy” (DT), is intended for patients who are not candidates for a transplant due to other medical conditions or advanced age. For DT patients, the device is meant to be a permanent solution, making device longevity the primary factor. If a TAH fails, the clinical response for a BTT patient is to expedite transplantation or urgently replace the device if the patient is stable enough.