The HeartMate 3 is a left ventricular assist device, or LVAD, that functions as a mechanical pump. For individuals with advanced heart failure, this device is designed to take over the work of the weakened left ventricle, the heart’s main pumping chamber. It helps circulate blood throughout the body, providing support when the heart can no longer meet the body’s demands on its own.
Indications for Use
The HeartMate 3 is intended for individuals with advanced, refractory left ventricular heart failure. This stage of heart failure is characterized by persistent and debilitating symptoms, such as shortness of breath and fatigue, that occur even at rest and do not improve with standard medical therapies.
Two primary strategies guide the use of the HeartMate 3. The first is “bridge-to-transplantation,” where the device provides mechanical circulatory support for patients who are eligible for a heart transplant. It effectively sustains them until a suitable donor heart becomes available.
The second strategy is “destination therapy.” This is a long-term solution for patients who have advanced heart failure but are not candidates for a heart transplant due to age, other medical conditions, or personal choice. For these individuals, the HeartMate 3 provides permanent support, improving their survival and ability to function in daily life. The device is contraindicated for patients who cannot tolerate anticoagulation therapy.
Device Components and Function
The central component is the internal pump, a small, centrifugal-flow device surgically implanted in the chest. This pump is connected to the apex of the left ventricle and to the aorta, the body’s main artery. Its function is to draw oxygenated blood from the left ventricle and propel it through the aorta to the rest of the body, effectively bypassing the weakened heart muscle.
A driveline, a thin, flexible cable, passes from the internal pump through an exit site on the skin of the abdomen. This driveline connects the implanted pump to the external components, transmitting power and relaying data to the external controller for monitoring.
The external components include a small, portable controller and a power source. The controller is a compact computer that operates and monitors the pump’s function, displaying information and providing alerts. Patients power the system using rechargeable 14V lithium-ion batteries, which last up to 17 hours and are carried in a shoulder bag or on a belt. While at home or sleeping, the system can be connected to a mobile power unit that plugs into a standard electrical outlet.
A technological feature of the HeartMate 3 is its Full MagLev™ Flow Technology. This design uses magnets to completely levitate the pump’s single moving part, the rotor, within the pump housing. This “contactless” rotation minimizes friction and shear stress on blood cells as they pass through the pump. The goal of this innovation is to reduce the risk of blood-related complications, such as clot formation and damage to red blood cells.
The Implantation Procedure
The implantation of the HeartMate 3 is performed by a cardiothoracic surgeon in a hospital operating room. The procedure is a form of open-heart surgery, and the conventional approach involves a median sternotomy, which is an incision through the breastbone to access the heart.
During the surgery, the surgical team places the patient on a heart-lung bypass machine, which temporarily takes over the function of the heart and lungs to circulate and oxygenate the blood. The surgeon then attaches the HeartMate 3 pump’s inflow cannula to the apex of the left ventricle and connects the outflow graft to the ascending aorta.
Another part of the procedure involves creating the driveline exit site. The surgeon carefully tunnels the driveline from the pump, through the diaphragm, and out through the skin of the upper abdomen. Once the device is fully connected and de-aired, the pump is started, and the patient is gradually weaned from the heart-lung machine as the LVAD takes over the support of the left ventricle.
Living with the HeartMate 3
A focus for patients is the daily care of the driveline exit site. This area where the cable exits the abdomen must be kept clean and dry to prevent infections, which requires regular dressing changes following a sterile procedure taught by the VAD team.
Managing the power supply becomes a constant part of the day. Patients must ensure their batteries are always charged and that they carry fully charged spares and a backup controller whenever they leave the house. The system’s controller provides audible and visual alarms to signal issues, such as low battery power or changes in pump flow, and patients must learn to recognize and respond to these alerts.
Lifestyle modifications are necessary to accommodate the device. While activities like walking, gardening, and golf are often possible and encouraged, contact sports are prohibited to avoid damaging the equipment. Showering requires a special waterproof bag to protect the external components, and swimming or bathing is not permitted due to the risk of infection and damage to the system. Travel is possible with careful planning in coordination with the medical team, including preparing for airport security.
Managing Potential Complications
One of the most common concerns is driveline infection, which can occur at the site where the cable exits the skin. Strict adherence to the sterile dressing change protocol is a defense against this risk.
Blood clots, or thrombosis, are another potential complication, as the presence of a foreign object in the circulatory system can trigger the body’s clotting mechanisms. To mitigate this, patients are required to take anticoagulant, or blood-thinning, medications for the life of the device. This necessary medication, however, also increases the risk of bleeding events, which can range from minor nosebleeds to more serious internal bleeding.
Regular and lifelong follow-up with a specialized VAD team is an important part of managing the device. These appointments allow the clinical team to monitor the patient’s health and the pump’s function, adjust medications, and provide ongoing education. Patients are taught to be vigilant for any unusual symptoms, such as fever, redness or drainage at the driveline site, or signs of bleeding, and to report them to their care team promptly.