The Heart of the Matter

A heart transplantation team at a major urban teaching hospital invariably has more candidates than hearts available to transplant. The program is known to benefit both low risk and high risk patients. Nevertheless, 30 percent of the candidates die before a heart becomes available. Members of the transplant team, who are both medical practitioners and scientific researchers, consider alternative sources of organs and decide upon the hearts of chimpanzees. The researchers realize that they are entering upon relatively uncharted waters, despite the close evolutionary link between human beings and chimpanzees. However, they have previously performed a series of preparatory experiments transplanting hearts between cynomologous monkeys and baboons. Though all the hearts were ultimately rejected due to the incompatibility of the two species' tissue types, there was temporary survival—an average of eleven weeks— sufficient to “buy time” for potential transplant recipients. If the analogy between monkey/ baboon and chimpanzee/human being holds, the chimpanzee heart could serve as a temporary “bridge” to a human heart, if and when it becomes available. For various reasons, medical and otherwise, the transplant team considers the chimpanzee heart preferable, as a bridge, to an artificial, mechanical heart. Moreover, it is possible that the chimpanzee heart could become a permanent replacement, if problems of immunological rejection could be overcome. Still further, this experiment might lead to scientific knowledge allowing the use of other types of animal hearts, for example, those of pigs or cows. This would solve—practically, if not ethically—the chronic problem of the insufficient supply of transplantable hearts. Confounding this possible human benefit and heady medical technology are certain inexorable facts. Chimpanzees are an endangered species. There are about 100,000 chimpanzees left in the world and about 2,500 in captivity in the United States. International trade in chimpanzees is banned, breeding in captivity is difficult, and capture of wild chimpanzees is “inefficient” in terms of preserving individual lives. For every wild chimpanzee captured and delivered to its destination, as many as 10 other chimpanzees die. Moreover, captive chimpanzees are much in demand for other forms of scientific and medical research. Finally, the scientific merits of using chimpanzees in research and particularly in this medical therapy carry a correlative ethical albatross. Can we, for such a purpose, ethically justify the use of such a complex and elaborate form of animal life, in several behavioral activities so close to our human selves? Should the transplantation team go ahead with its experiment? Should the project be approved by the institution's Institutional Review Board and Animal Care and Use Committee?