Heart-kidney transplantation: Is 2 really better than 1?

In October 2018, after more than 2 years of policy development, the Organ Procurement and Transplantation Network (OPTN) implemented a modified heart allocation system aimed at better stratifying the most medically urgent transplant candidates and reducing geographic disparities in access to donor hearts. Among patients waitlisted and transplanted under the new system, recent studies suggest reduced waitlist times, no difference in waitlist mortality, and noninferior posttransplant survival compared with patients waitlisted and transplanted under the old system. 1 Lazenby K.A. Narang N. Pelzer K.M. Ran G. Parker W.F. An updated estimate of posttransplant survival after implementation of the new donor heart allocation policy. Am J Transpl. 2022; 22: 1683-1690 Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar , 2 Wolfson A.M. DePasquale E.C. Fong M.W. et al. UNOS policy change benefits high-priority patients without harming those at low priority. Am J Transpl. 2022; 22: 2931-2941 Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar , 3 Wolfson A.M. DePasquale E.C. Starnes V.A. et al. Effect of UNOS policy change and exception status request on outcomes in patients bridged to heart transplant with an intra-aortic balloon pump. Artif Organs. 2022; 46: 838-849 Crossref PubMed Scopus (10) Google Scholar These studies, however, excluded heart-kidney candidates and recipients. Until now, the only published study in the heart-kidney population demonstrated worse 1-year posttransplant survival in recipients of heart-kidney transplants performed after the allocation policy change compared to recipients transplanted before the policy change took effect. 4 Afflu D.K. Diaz-Castrillon C.E. Seese L. Hess N.R. Kilic A. Changes in multiorgan heart transplants following the 2018 allocation policy change. J Card Surg. 2021; 36: 1249-1257 Crossref PubMed Scopus (8) Google Scholar Francke et al in this issue of the journal have verified these findings and, more importantly, demonstrated that before the allocation change, heart-kidney recipients had similar 1-year survival to heart-only transplant recipients. 5 Francke M. Wolfson A.M. Fong M.W. et al. New UNOS allocation system associated with no added benefit in waitlist outcomes and worse post-transplant survival in heart-kidney patients. J Heart Lung Transpl. 2023; Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar What has caused such a dramatic change in survival for heart-kidney transplant, and how will the new OPTN heart-kidney transplant criteria as well as the safety net policy 6. OPTN Policy Changes: Establish eligibility criteria and safety net for heart-kidney and lung-kidney allocation. Available at 〈https://optn.transplant.hrsa.gov/media/erucde2m/policy-notice_est-elgblty-crit-and-safety-for-hrt-kid-and-lung-kid-alloc_mot.pdf〉 (Accessed July 18, 2023). Google Scholar affect this outcome?