Doctors to implant first self-contained total artificial heart
Thursday, April 19th 2001, 12:00 am
By: News On 6
WASHINGTON (AP) _ An American on the brink of death soon will receive the first self-contained, mechanical total heart replacement in a landmark surgery experts hope will lead to new hope for patients with failing hearts.
Heart surgery teams at five hospitals are trained and poised to remove a diseased natural heart and install in its place an electric-powered pump designed to fit inside the chest with no wires or tubes sticking through the skin.
Officials of Abiomed Inc., which developed the mechanical heart, said Wednesday that the first surgery, no later than June 30, would proceed without prior announcement and that the patient's identity may not be released. Results of the procedure, they said, would not be made known to the public for at least 30 days.
David M. Lederman, president and chief executive officer of Danvers, Mass.-based Abiomed, said the company received Food and Drug Administration approval to perform at least five human trials with the artificial heart, known as AbioCor. If the experiments are successful, more patients could be added to the trial later, he said.
The patients selected for the trial must be suffering from a chronic, progressive heart disease expected to result in death within 30 days.
The goal of the experimental trials with the artificial heart, said Lederman, is to ``double the life span of these patients,'' to 60 days.
``Every patient will probably die on the AbioCor,'' he said. ``We need to understand that, with this new technology, we may have failures.''
Lederman said a second goal is to evaluate how the unattached, mobile mechanical heart affects the quality of life of those patients, most of whom are so ill that they cannot walk or perform the daily routine of life, such as getting dressed.
Less advanced mechanical hearts have been implanted in patients in the past, but they were all attached to outside electrical or pumping power consoles. Some such devices are still used as a ``bridge,'' keeping patients alive until a heart transplant is available. There also are devices that take over only part of the heart's job, the left ventricle. One such device, developed at the University of Pennsylvania, is self-contained within the chest. It has been used a few patients in Europe and one in the United States, according to Dr. Michael Acker of the University of Pennsylvania.
The AbioCor is the first mechanical device designed to replace the entire heart that is totally self-contained within the chest and not connected to outside power or pumps, Lederman said.
About 700,000 Americans annually die of heart failure. About half die suddenly, with no chance for therapy. Heart transplantation is the best hope for most of the others, but only about 2,000 organs are available each year, Lederman said.
He estimated that about 100,000 Americans annually could prolong their lives with a proven, reliable mechanical heart.
The AbioCor device does not resemble a real heart, but looks more like what it is: a pump made of titanium and plastic with four protruding tubes that are connected to the body's cardiac vessels. There are internal mechanical valves that mimic the action of the natural heart's pump system.
Power comes from a battery pack worn outside the body. A coil sends power through the skin to an implanted coil that then carries the power to an implanted control package and backup, short-term battery.
The external battery pack must be recharged every four hours, but the patient can wear a spare package. The internal battery is kept charged and can operate the heart for about 30 minutes without the external battery.
``This not only will extend life, but it also restores the quality of life for these patients,'' said Robert T.V. Kung, Abiomed's chief scientist. ``Patients will be able to shower, change clothes and walk around.''
Sensors command the mechanical heart to pump faster when the body is exercising and muscles need more oxygen, Kung said.
The pump, implanted in the chest, and its support devices, implanted in the abdominal cavity, weigh a total of 3 pounds. The external battery pack and monitor, worn on a belt, weigh about 4 pounds.
Lederman said the complete heart replacement device costs about $75,000 and will cost another $175,000 for procedure expenses.
Kung said the performance of the mechanical heart can be monitored constantly at a remote center. A low frequency radio signal is sent from the external monitor worn by the patient, picked up by a transmitter and relayed to a central computer that reads the pumping rate, temperature and general condition of the artificial heart.
Lederman said his company has spent 30 years developing AbioCor, but the device is still in the experimental stage.
``We are designing a system that will have a five-year life, but we aren't there yet,'' he said.
Lederman said the five hospital sites approved for implanting the AbioCor are Brigham & Women's and Massachusetts General in Boston; Hahnemann University Hospital in Philadelphia; the Texas Heart Institute in Houston; the Jewish Hospital in Louisville, Ky.; and the UCLA Medical Center in Los Angeles.