The Food and Drug Administration (FDA) has approved a partial artificial heart intended to keep people alive in the hospital while they are awaiting a heart transplant.

The product is a pulsating bi-ventricular device that is implanted into the chest to replace the patient’s left and right ventricles (the bottom half of the heart). The implanted device is sewn to the patient’s remaining atria (the top half of the heart). Hospitalized patients are connected by tubes from the heart through their chest wall to a large power-generating console, which operates and monitors the device.

The heart is manufactured by Syncardia Systems Inc., of Tucson, Ariz. It is intended as a “bridge to transplant” for people waiting for a heart transplant who do not respond to other treatments and are at risk of imminent death from non-reversible bi-ventricular failure, i.e. people with both left and right side heart failure, and who are eligible for a heart transplant.

FDA approved the Syncardia device based on a review of clinical studies of safety and effectiveness conducted by the firm and on the recommendation of an outside panel of experts convened by FDA to review the device.

The firm studied use of the artificial heart in 81 transplant-eligible patients with severe bi-ventricular heart failure at five medical centers in the United States. In the studies, 79 percent of patients implanted with the heart remained alive long enough to receive a donor heart (an average of 79 days), demonstrating that the artificial heart could successfully serve as a bridge to transplant.

Complications included infection (72% of patients), bleeding (42%), neurological event such as major or minor stroke (25%) and device malfunctions (18%). Seventeen patients in the study died before a donor heart became available.

About 4,000 patients in the United States await heart transplants annually. Only about 2,200 donor hearts typically become available. About 100 of the 4,000 patients awaiting transplants have non-reversible bi-ventricular failure and could be candidates for the new artificial heart.

FDA is requiring the firm to conduct a post-approval study to monitor the device’s performance in commercial use.