Center Volume Predicts Improved Early Outcomes in Multiorgan Heart Transplantation

Abstract

Center volume is associated with improved survival after isolated heart transplant, but its impact on multiorgan heart transplant (MHT) outcomes is unknown. This study examines the impact of institutional MHT volume on MHT outcomes. Adult patients undergoing first time MHT from 2011 to 2021 were identified in the United Network for Organ Sharing database. Transplant centers were annually classified as low-, medium-, or high-volume if they performed <3, 3 to 5, or ≥6 MHTs that year, respectively. Graft failure was defined as death, failure, or re-transplantation of any allograft. A total of 1860 MHTs were performed at 104 centers, including 482 (26%) at low-, 601 (32%) at medium-, and 777 (42%) at high-MHT volume centers. Noncardiac allografts included kidney (83%), liver (16%), and lung (2%). The proportion of MHTs performed at high-volume centers increased from 10% in 2011 to 62% in 2021. Recipient age, race, and body mass index did not vary by center volume (all P > .05). Patients at high-volume centers were more likely to be in the intensive care unit pre-transplant (58% vs 44%, P < .001) and have shorter waitlist times (47 vs 92 days, P < .001) than those at low-volume centers. 30-day graft survival was higher in combined medium- and high-volume compared with low-volume centers (95% vs 92%, P = .004). Increasing center MHT volume was protective against 30-day graft failure (adjusted hazard ratio 0.93 [0.88-0.98]) on multivariate Cox regression. Higher MHT volume is associated with improved early graft survival after MHT, which may justify centralizing the performance of MHTs to high-volume centers.