Dear Editor:

Patients with heart failure who are listed for heart transplant (HTx) have a high mortality rate while on the wait list due to progressive organ dysfunction in a state of organ shortage.¹ In this report, we analyzed the organ utilization and wait list mortality of HTx candidates in the Eurotransplant database during the period from 2009 to 2018.

The number of patients actively waiting for a cardiac allograft remained consistently high over the past decade, with approximately 1050 patients being listed each year. However, a reduction in the number of new registrations was observed over the latter years of observation, with 1096 new registrations in 2009 compared with 901 new registrations in 2018 (P < .001; Figure 1A). Despite the persistently high demand for organs, we observed no change in overall donation rates during the 10-year period. However, donations from donors aged from 56 to 64 years and donations from donors after cardiac death increased 2-fold (data not shown). This trend was consistent on a national level for each Eurotransplant member. Furthermore, we observed a reduction in the number of organs that were not utilized (not accepted or accepted and not transplanted) after initial offer (P < .05; Figure 1B). Finally, there was also a 2-fold increase in the number of organs that were exchanged between Eurotransplant countries, from 88 in 2010 to 164 in 2019 (P = .03; data not shown).

The striking finding of our analysis was the dramatic decrease in wait list mortality, from 22.1% in 2009 to 11.3% in 2018 (P < .001). This dramatic decrease in mortality was unique for HTx and was not seen for other solid organs. More specifically, wait list mortality significantly increased from 5% to 5.9% (P = .0053) and from 21.7% to 29.6% (P = .0076) among patients waiting for kidney and liver allografts, respectively (Figure 1C). In addition, the decrease noted in wait list mortality for HTx patients started before 2013 (which was the starting year for ventricular assist devices on the registry) and continued steadily over the years (Figure 1C). Finally, we found a significant increase in the proportion of patients waiting for more than 12 months on the HTx wait list (46.3% in 2009 vs 55.9% in 2018; P < .05; Figure 1D). Finally, there was an increase in ventricular assist device utilization in patients with high urgency status (not reported in 2009 vs 151 in 2018; P < .001; Figure 1E).

Despite the limitations of this analysis, the wait list mortality for HTx candidates in the Eurotransplant database has significantly decreased over the past decade, which was unique compared with mortality rates for other organs in the same period of time.² These trends are likely explained by improved organ utilization combined with the widening of the donor pool and can be partially reflected by the increased organ exchange among Eurotransplant countries. Furthermore, the utilization of ventricular assist devices as a bridge to transplant may have also contributed and could perhaps explain the concomitant increase in the time on the wait list.³ However, HTx still remains the best therapeutic option for eligible patients with end-stage cardiac disease (with the exception of those who get ventricular assist device treatment as destination therapy). Despite these encouraging results, the heterogeneity of policies within the Eurotransplant network with regard to organ allocation and high urgency status might affect HTx outcomes.⁴ The efforts to increase the pool of organs as well as to optimize the utility of already available organs should be continued.⁵

References:

1. Stehlik J, Wever-Pinzon O. The heart transplant waiting list and the interplay of policy and practice: in search of fairness. Circ Heart Fail. 2017;10(12):e004657. doi:10.1161/CIRCHEARTFAILURE.117.004657
   
2. Moris D, Schmitz R, Dimitrokallis N, Schmidt T, Vernadakis S. The paradox of increasing waiting list mortality and declining utilization of deceased donor grafts in kidney transplant. Exp Clin Transplant. 2021;19(1):92-93. doi:10.6002/ect.2019.0427
   
3. Mastrobuoni S, Dell'Aquila AM, Van Caenegem O, Poncelet A, Jacquet LM, Garcia J. Do Patients supported with continuous-flow left ventricular assist device have a sufficient risk of death to justify a priority allocation? A propensity score matched analysis of patients listed in UNOS Status 2. Transplantation. 2018;102(6):e288-e294. doi:10.1097/TP.0000000000002105
   
4. Smits JM. Actual situation in Eurotransplant regarding high urgent heart transplantation. Eur J Cardiothorac Surg. 2012;42(4):609-611. doi:10.1093/ejcts/ezs424
   
5. Moris D, Tsilimigras DI, Bokos J, Vernadakis S. Organ donation after circulatory death in Greece: time to consider. Exp Clin Transplant. 2020;18(4):539-540. doi:10.6002/ect.2019.0100