A Throwaway Society or Good Stewards? Drs Richard Kirk & Anne Dipchand
Following the success of the change in donor policy at Children's Health I felt it was important to disseminate the message more widely and so the ISHLT Consensus Statement on Donor Organ Acceptability & Management in Pediatric Cardiac Transplantation (DOAM) was conceived. Click or copy and paste this link into your browser: http://www.crkirk.com/videos/The_DOAM_Project.mp4 to see a short video of how the DOAM project was conceived in Dallas.
As transplant providers we have many responsibilities, but none are more important than providing the best chance of a successful transplant for our patients and being good stewards of the donor pool. All of us however recognize that sometimes these two responsibilities are in conflict.
Let us examine the responsibility to provide the best chance of a successful transplant. A Medline search shows that the majority of our literature is focused on outcomes from transplant rather than from listing. Whilst understandable, and in part due to the fact that the ISHLT registry data only contains information from transplant, it ignores the waitlist mortality and morbidity which is by no means negligible. Waitlist mortality in the USA and Europe respectively is 14% and 18% whilst mortality in the first year after Tx is 7-12%.1–3 Therefore the highest risk for our patients is actually during the waitlist period. This is also true of morbidity. In the recent era of VADs some 50% of our patients receive mechanical support whilst waiting for transplant and between 7% and 29%, depending on the type of device support, will have had an adverse neurological event after three months on support.4,5 To have a successful transplant one thus needs a suitable donor, in a timely fashion and to accrue the least possible morbidity whilst waiting and throughout the transplant process.
What about the responsibility to be good stewards of the donor pool? We all recognize the gift families make when a loved one dies and they initiate the donation process - we can only guess at the anguish for each and every one. Of course not all donated hearts are suitable for transplantation; however the quandary is that some donated hearts are usable and yet ultimately discarded. This not only does a disservice to potential recipients but diminishes the donor family’s gift. Does this happen and if so how often? Well there is every likelihood that it happens across the global transplant community although the incidence may vary from one region to another. 44% of all donated hearts are ultimately discarded in the USA – for the most part the stated reason is questionable donor quality for fear that it may impact on post-transplant outcomes. The European discard rate (25%) appears to be lower than the USA and yet overall survival between North America and Europe is not significantly different.
Whilst post-transplant outcomes are important, donor factors in general provide only a small increase in the risk of death. For example the relative risk of adverse outcomes for an ischemic time more than six hours is 1.7.6 In contrast the odds ratio for a ventilated recipient not surviving to discharge after transplant is 3.3 and if on ECMO, 5.6.6 Recipient risk factors therefore far outweigh donor factors. Indeed a recent analysis of the USA data shows that if 1 year outcome from listing is assessed irrespective of whether transplant occurs then accepting the first donor organ is more likely to lead to survival at one year than if it was refused.7 Thus it is even more important that we endeavor to use as many offered donor organs as possible.
One potential way to reduce waitlist mortality and morbidity and to ensure the transplant recipient is in optimal condition is to reduce the waitlist time. But how can we reduce waitlist time in the face of a limited donor pool which despite intense efforts over the years has failed to increase in size and in some jurisdictions is decreasing?8 Obviously one potential strategy is to reduce the organ discard rate. To this purpose the Donor Organ Acceptability & Management (DOAM) project aims to understand better why the discrepancies in discard rates occur, attempts to balance the waitlist and post-transplant mortality and morbidity outcomes, and define the interplay between recipient and donor risk factors. We hope that the end result of this project will be a reduction in pre and post-transplant adverse outcomes for our patients and better stewardship of the most precious gift a bereaved family can give – a donated organ.
- Law SP, Oron AP, Kemna MS, et al. Comparison of Transplant Waitlist Outcomes for Pediatric Candidates Supported by Ventricular Assist Devices Versus Medical Therapy. Pediatr Crit Care Med. 2018;19(5):442-450. doi:10.1097/PCC.0000000000001503
- Smits JM, Thul J, De Pauw M, et al. Pediatric heart allocation and transplantation in Eurotransplant. Transpl Int. 2014;27(9):917-925. doi:10.1111/tri.12356
- ISHLT Registry Slides 2017. http://www.ishlt.org/registries/slides.asp?slides=heartLungRegistry. Accessed October 2, 2017.
- Rossano JW, Cherikh WS, Chambers DC, et al. The Registry of the International Society for Heart and Lung Transplantation: Twentieth Pediatric Heart Transplantation Report-2017; Focus Theme: Allograft ischemic time. J Heart Lung Transplant. 2017;36(10):1060-1069. doi:10.1016/j.healun.2017.07.018
- Rosenthal DN, Almond CS, Jaquiss RD, et al. Adverse events in children implanted with ventricular assist devices in the United States: Data from the Pediatric Interagency Registry for Mechanical Circulatory Support (PediMACS). J Heart Lung Transplant. 2016;35(5):569-577. doi:10.1016/j.healun.2016.03.005
- Rossano JW, Dipchand AI, Edwards LB, et al. The Registry of the International Society for Heart and Lung Transplantation: Nineteenth Pediatric Heart Transplantation Report-2016; Focus Theme: Primary Diagnostic Indications for Transplant. J Heart Lung Transplant. 2016;35(10):1185-1195 doi:10.1016/j.healun.2016.08.018
- Davies RR, Bano M, Butts R, Jaquiss RD., Kirk R. Donor Organ Turn-Downs and Outcomes Following Listing for Pediatric Heart Transplant. J Heart Lung Transplant. September 2018. doi:10.1016/j.healun.2018.09.026
- Macgowan GA, Parry G, Schueler S, Hasan A. The decline in heart transplantation in the UK. BMJ. 2011;342:d2483