In the U.S., the median wait time for a heart transplant is over 4 months and is growing longer due to a shortage of donor organs. The use of implantable heart pumps in Bridge to Transplant Therapy is often necessary for advanced heart failure patients who are at risk of passing away before a matching donor becomes available.
Our center currently implants two devices for Bridge to Transplant therapy: the HeartMate II and the CardioWest Total Artificial Heart.
HeartMate II (Thoratec)
The HeartMate II is a small, silent left ventricular assist device (LVAD) that is implanted below the patient’s heart in his or her abdomen. This device does not replace the heart, but assists the pumping function of the left ventricle. The HeartMate II is capable of pumping up to 10 liters of blood per minute. The pump utilizes only one moving part (a pump rotor), giving it enhanced durability over earlier generation devices. Patients with the HeartMate II are discharged home with a wearable power system. The HeartMate II is FDA approved.
HVAD Pump (HeartWare)
HeartWare HVAD Pump is a miniaturized left ventricular assist device
that is implanted in the pericardial space adjacent to the heart, and
may be implanted in small adults and adolescents. The pump is the
smallest on the market to date, weighing 140 grams with an outer
diameter of approximately 4 centimeters. The HVAD pump utilizes passive
magnetic and hydrodynamic forces to levitate and rotate an impeller.
Once power is applied to the device, there are no points of mechanical
contact between the impeller and the body of the pump, giving it the
potential for extended durability. Patients with the HeartWare
device are discharged home with a wearable power system. The HVAD is FDA approved for Bridge to Transplant.
CardioWest Total Artificial Heart (SynCardia)
The CardioWest Total Artificial Heart is the predecessor of the Jarvik-7 Total Artificial Heart that was implanted in Barney Clark in Utah in 1982. The Total Artificial Heart is an air-driven pump that is implanted as a bridge to human heart transplantation in patients who have severe right and left-sided heart failure. The failing native heart is removed prior to implantation. The pump is driven by a large console that provides compressed air in pulses to power the artificial heart. After implantation of the Total Artificial Heart, most patients experience improved blood perfusion to other organs in the body, physical rehabilitation, and survival to heart transplantation.
The Thoratec PVAD (paracorporeal ventricular assist device) is a heart pump that sits outside the body. The pump is most often used to support the right ventricle, though it can also be used to support the left, or both sides of the heart. The patient's own heart remains in place during PVAD support. Patients are discharged home with a console similar to a small console suitcase.