Washington University heart surgeons use the latest generation of artificial heart assist devices as a temporary support system or “bridge to transplantation,” buying time in patients whose weakened hearts may deteriorate during the wait for a donor heart. Some of these devices also are implanted as permanent support systems in end-stage heart failure patients who are not candidates for heart transplantation.
Typically, heart failure patients reach a stage at which breathing and simple exertion are difficult because the heart is unable to efficiently pump blood to the rest of the body. Many of these patients are candidates for heart transplant. Typically, ventricular assist devices (VADs) are used to restore cardiac function in this group of patients while they await transplants. Meanwhile, those with implanted VADs are given top priority in receiving donor hearts, the allocation of which is limited.
A VAD is implanted below the patient’s heart and connected to the left ventricle to help the heart pump blood. Early VADs were large and heavy and used a diaphragm or plate that drew blood in and pushed it out. The next generation of VADs has fewer moving parts and is much smaller, quieter and more lightweight.
In recent years, many heart transplant patients at Barnes-Jewish Hospital have been implanted with next-generation VADs as participants in clinical trials of these devices.
These devices include the HeartMate ® II and HeartWare ® left ventricular assist systems, which are both small, quiet blood pumps that restore hemodynamic function and provide long-term circulatory support. The HeartMate II device is now approved as both a bridge to transplantation and destination therapy. The Heartware is an investigational device in the United States and is still undergoing clinical trials
The new generation of VADs not only improve the heart’s pumping function, but can help restore a better quality of life in patients. Patients who receive the devices are sent home to await transplant after the pumps are implanted.
Patients with end-stage heart failure who are not candidates for transplant may receive the HeartMate ® II left ventricular assist system as a permanent support system. The Artificial Heart Program at Washington University School of Medicine is one of the few centers in the United States with expertise in the use of cardiac assist devices for permanent support.
Patients who have severe heart failure (of both the left and right ventricles), comprising about 5-10% of heart failure patients, may receive the CardioWest TM temporary Total Artificial Heart (TAH-t) as a bridge to transplant. The pump is driven by a pneumatic console that provides compressed air.
Before placement of the artificial heart, the native failing heart is removed. After implantation, most patients experience improved blood perfusion to other organs, physical rehabilitation and survival to heart transplantation.
The CardioWest TM TAH-t is an improved version of the Jarvik-7 artificial heart. The U.S. Food and Drug Administration (FDA) approved the artificial heart in 2004 as a bridge to transplant for patients at risk of imminent death from non-reversible biventricular failure. When Washington University heart surgeons completed training in late 2006, they became one of only nine surgical teams in the country qualified to implant the CardioWest TM TAH-t.
Other ventricular assist devices also may be used for short- to intermediate-term support of failing hearts. The TandemHeart® Percutaneous Ventricular Assist Device is placed outside the body with cannula (tubing) inserted through the skin into the femoral vein in the upper leg and advanced into the left atrium. The device may provide support for up to a couple of weeks.
The Artificial Heart Program has three nurse coordinators who are dedicated to the teaching and care of patients with artificial heart assist devices. The program also works closely with the Rehabilitation Institute of St. Louis to provide physical therapy for its patients.
For more information about the Artificial Heart Program, call:
(888) 800-9484 (toll free)