A ventricular assist device (VAD) is a type of device that is designed to take over function for either or both of the heart’s ventricles. The ventricles are responsible for pumping blood through the lungs and out to the body. Most often, VADs are used in patients who are awaiting a heart transplant, thus they are called “bridges to transplantation.” There are, however, other situations in which a VAD might be recommended.

VADs may be short-term, intermediate-term or long-term, depending on the needs of each patient. A VAD that supports only the left ventricle in known as a left ventricular assist device (LVAD), and a VAD that supports that right ventricle is known as a right ventricular assist device (RVAD). Devices that support both ventricles are known as bi–ventricular assist devices (BiVADs).

The most common VADs used in the United States are implanted during open-heart surgery. They are powered by a pump that remains outside of the body and pumps the blood through tubes that are connected to the patient’s circulatory system. Some VADs require constant supervision in a medical setting, while others are portable and allow the patient to return to a more natural lifestyle.

Although VADs were first developed in the 1960s, it took almost 20 years of clinical experimentation before they were put into general use. Since then, VADs have continued to increase in sophistication, becoming smaller and more efficient. Today, studies have shown that patients on VADs who are awaiting heart transplant may be successfully weaned off the VAD without a transplant. This is possible because the VAD allows the heart to rest, enabling it to regain function.

In addition, a permanent model has been approved by the U.S. Food and Drug Administration (FDA) for use in some terminally-ill patients not eligible for heart transplantation. This permanent support using a VAD is called destination therapy. Clinical trials demonstrated that destination therapy doubled the one-year survival rate of patients with end-stage heart failure, as compared to drug treatment.

In 2004, the American College of Cardiology and the American Heart Association recommended that left ventricular assist devices (LVADs) be viewed as permanent rather than temporary therapy for certain late-stage heart disease patients.

Nevertheless, there are significant side effects associated with VADs, including blood infection and blood clots, and many patients are not suitable candidates for VADs. Researchers are continually working to develop new and better models to address these concerns.

There is one VAD currently approved for use in children. It is designed for children 5 to 16 years of age with severe left ventricular heart failure. The VAD may allow children with this heart problem to survive while awaiting a heart transplant. Researchers are continuing to work on pediatric VADs that may be implanted in children, however, there are none currently approved on the market.