For giving mobility to artificial- heart recipients.
SynCardia makes the Total Artificial Heart, the only complete heart-replacement device approved by the FDA. Last year, it began a clinical study for its Freedom portable driver, a 13.5-pound external power source that, for the first time, lets survivors of advanced heart disease return home with the implanted mechanism. They're no longer tethered to a 418-pound power supply at the hospital. One patient, an Oklahoma pastor, has returned to the pulpit.
As far back as the late 1940s, researchers and surgeons began trying to develop a device to replace diseased and failing hearts. In 1969, after years of animal studies, the first human to get an artificial heart survived nearly three days. Later versions got better results, of course: 79% of patients enrolled in a 1993-2003 SynCardia study lived long enough on the device to receive a human-heart transplant. In 2004, the FDA approved its use as a "bridge" device before a transplant. In all, surgeons have implanted more than 900 man-made hearts.
The Total Artificial Heart has a fixed rate of 125 beats per minute. "It sounds like galloping horses," says SynCardia cofounder and heart surgeon Dr. Jack Copeland. "DA-da-duh, DA-da-duh." The device, which costs about $125,000, adapts to increased blood flow during exertion through its pneumatic design. Incoming blood displaces air, partially filling a polyurethane diaphragm before fully ejecting the fluid. The body regulates how much blood the artificial heart pumps and returns blood to the heart as needed. The Freedom driver works so hard--180,000 beats a day, pumping as much as 13,680 liters of blood through the body--that patients must visit the hospital every two months to have it serviced.
More than 400,000 people a year die of heart disease, and more than 3,000 are waiting for heart transplants. SynCardia is developing smaller and longer-lasting power supplies, ultimately in hopes of getting FDA approval for a permanent heart replacement. Trials could begin this year. The 22 patients now using the Freedom driver have lived an average of 10 weeks with the artificial organ. But they can't touch the longest-surviving SynCardia recipient, a gentleman in Italy. Because of an antibody incompatibility, he is unable to receive a transplant. No matter. He rides his bike around town carrying the power supply for his heart. The device has been galloping along for more than three years.