The Food and Drug Administration on Thursday granted Pennsylvania State University's Hershey Medical Center permission to perform the first experimental implantations of a temporary artificial heart, only one week after a 33-year-old Arizona man was given an unsanctioned device in a controversial emergency procedure in Tucson.
The Hershey medical team was approved to perform six operations using the air-powered artificial heart, known as the "Penn State heart," a device that will serve only as a "bridge" until a human donor heart becomes available for transplantation.
Dr. William S. Pierce, who developed the heart, is expected to perform the first operation, although Hershey officials said there are no current candidates for the procedure.
The use of an unauthorized artificial heart raised ethical and legal questions last week after Thomas Creighton, a 33-year-old auto mechanic, died at the University of Arizona Medical Center in Tucson after an extraordinary series of transplant operations involving two human hearts and an unapproved artificial heart.
The so-called "Phoenix heart" was used by surgeons as a stopgap in an attempt to save Creighton's life after his first human donor heart failed. The artificial heart, designed by Phoenix dentist Kevin Cheng, has not been sanctioned by the FDA, which is required by law to approve the use of experimental medical devices. The federal agency is investigating the episode.
Creighton's death was not attributed to the artificial heart but to an accumulation of fluid in his lungs caused by 10 hours on a heart-lung machine that maintained his circulation before the Phoenix heart was implanted.
Until now, the only artificial heart approved by the federal government for experimental use in humans is the Jarvik-7, a permanent artificial heart that has been implanted in three patients: Dr. Barney Clark in Utah, who died after 112 days, and William J. Schroeder and Murray P. Haydon, both of whom remain hospitalized in Louisville, Ky.
Unlike the permanent Jarvik-7 heart, the temporary Penn State heart has the ability to react automatically to changes in a patient's blood-flow requirements, officials at Penn State University said. The Jarvik-7 has to be manually adjusted by an attending physician to adapt to blood-flow demands for various activities, they said.
"For example, when the patient needs to sit up in bed, the heart has to pump more blood than it does when the patient is lying flat--the Penn State heart automatically adjusts to the increased blood flow demands," said a statement released by the university.
Weighs One Pound
The fully constructed Penn State heart weighs about one pound, similar to the weight of a human heart. It is also similar in size to a human heart and is designed to fit inside the chest of an individual weighing 155 pounds or more. It is powered by two air hoses connected to a bedside air compressor drive unit.
The Penn State heart, described by Pierce in a statement as a mechanism to support patients "who are dying because no donor organ is available," is capable of sustaining an individual for a period of weeks or even months, university officials said. They said the device has been tested in more than 50 animals and that one calf lived 270 days with the artificial
heart. Permission to use the heart, the result of 15 years of research, was requested from the FDA last December.
Carl Andrews, a spokesman for the Hershey Medical Center, told the Associated Press that physicians there do not view the artificial heart as an answer to patients' long-term medical problems.
Younger Than 55
Pierce said that "to ensure optimal probability of survival," candidates for the Penn State heart must be younger than 55 years old, have good function in their other vital organs, demonstrate no evidence of infection or lung damage and not be insulin-dependent diabetics.
In addition, he said, they must "possess a good family support group and a good personal mental health state." University officials said patients will only be considered for an artificial heart after all other conventional treatments have failed.
The Hershey Medical Center was established in 1963 with a $50-million grant from the M. S. Hershey Foundation, a philanthropic foundation created by the chocolate manufacturer.