The Total Artificial Heart: The TAH as Bridge
The TAH as Bridge
Many scientific observers propose that the TAH be employed only as a temporary bridge until a donated heart can be implanted. One quarter of heart transplant candidates die while waiting for a donor heart. The shortage of donor hearts and the increasing success and availability of heart transplantation have led to an eight-fold increase in the waiting time of critically ill patients for a donor heart. Many believe that clinical experience with the TAH as a bridge will lessen the need for further trials of permanent TAH implantations. Critics point out that deployment of the TAH as a bridge increases the pool of persons awaiting transplantation without increasing the supply of donor hearts. The possibility that the limited supply of donor hearts might be preferentially allocated to persons on a bridge in order to minimize TAH-related morbidity has been especially controversial.
This proposal would permit patients or a transplant center to elect the TAH in order to compete more effectively for scarce donor hearts. The incentive to choose a TAH becomes greater as the bridge TAH is more widely used and as bridge-supported patients take an increasing portion of the inelastic supply of donor hearts. In the absence of public subsidies for TAH bridges, this practice would tend to allocate donor hearts to persons wealthy enough to extend their stay in the recipient pool by purchasing a pretransplant bridge. Ultimately, the constraining effect of the donor shortage will lead to longer stays and greater attrition of persons waiting on the TAH bridge, just as has happened for cardiac transplantation without the TAH. Such a development would increase the cost of end-of-life care for persons not receiving a transplant by $100,000 per patient. buy zithromax
Some observers believe that the bridge application might have salutary effects on heart transplantation. Current practices must hurriedly match a donor heart and a small group of imminently dying patients. A large, varied pool of TAH-supported patients might allow allocation of donor hearts to more medically suitable candidates. Some experts believe that as many as 10 percent of currently harvested hearts are wasted because of the unavailability of a suitable candidate. The availability of a pool of transplant-ready TAH supported recipients might decrease this waste of a scarce medical resource and increase the number of hearts successfully used for transplantation.