The Total Artificial Heart: TAH Bridges and Patient Choices
TAH Bridges and Patient Choices
The availability of TAH bridges imposes a complex and poignant decision on patients with heart failure. Those electing a TAH bridge incur substantial additional costs without a guarantee that a donor heart will become available. Those wanting a transplant, but declining the costs and burdens of the TAH bridge, might justifiably fear that this decision decreases their chance of receiving a donor heart. This Faustian gamble will have profound emotional and financial consequences for family members as well. Public awareness of such choices might help mobilize additional donor hearts, but it would take a 15-fold increase in the efficiency of donor heart harvesting to meet the projected need for donated hearts for transplantation.
Quota for TAH Bridges
A public policy quota might alleviate the adverse consequences of unrestrained TAH bridge deployment by reserving a fixed percentage, perhaps 90 percent, of donor hearts for non-TAH-supported patients. This would reserve 10 percent of donor hearts for bridge patients, approximating the maximum number of donor hearts that may be wasted for want of a suitable transplant candidate. Such a quota rests on the premise that all transplant candidates have equally dire need and that using a TAH to prolong life beyond the failure of a natural heart is a benefit that does not create a priority claim to a donor heart. This quota could be enacted as part of a multi-center protocol to prospectively study the extent to which the bridge improves donor-recipient matching, decreases wastage of donor hearts, increases donor recruitment, or facilitates permanent TAH development. It might be enforced by restricting either TAH site licensing or access to public funds for TAH implantation. there
Limitations of TAH Bridge Research
Some advocates of permanent TAH implantation trials believe that restricting the TAH to bridge use would slow permanent TAH development. TAH bridge patients wait an average of only 18 days (range 1- to 111 days) for transplantation, presenting little opportunity for extended study of TAH use. Research on bridge-dependent patients is constrained by the moral obligation to safeguard the future transplant, invasive studies that might introduce infections in patients about to be immunosuppressed might not be possible. Finally, additional trials of permanent implantation will likely yield information that will benefit shortterm bridge patients.