Regional variation in the outcomes of MELD-Na based liver allocation
Chau L, Moonka D, Collins K, Rizzari M, Yoshida A, Abouljoud M, and Nagai S. Regional variation in the outcomes of MELD-Na based liver allocation. Am J Transplant 2018;18(Suppl 4):573.
Am J Transplant
Introduction: While there is known geographic discrepancy in waitlist and transplant outcomes in the MELD era, there is a paucity in understanding of these variations compared to the MELD-Na era. Methods: Adults registered for deceased liver or liver-kidney transplant from the UNOS registry were examined. They were divided into MELD-era composed of patients who were registered between July 1, 2013 and December 31, 2015 (n=18,014) and MELD-Na era composed of patients who were registered between January 1, 2016 and March 31, 2017 (n=10,187). Patients with any approved exception points were excluded. Transplant regions were grouped into Low (<23: Regions 1, 8, 9, 10), Medium (24-26: Regions 2, 3, 4, 11), and High (≥27: Regions 5, 6, 7) groups based on median laboratory MELD/MELD-Na score. Multivariable Cox regression models were used to compare transplant and waitlist mortality across geographic regions between both eras. Mortality risk was adjusted by hepatitis C status, Karnofsky <30%, donor risk index, and dialysis requirement. The survival benefit of liver transplantation was compared between the two eras and is expressed as a hazard ratio comparing mortality rate of transplant recipients compared to candidates on the waiting list of equal MELD/MELD-Na categories. Results: The hazard of waitlist mortality significantly decreased in the MELD-Na era (HR: 0.621, P<0.0001) compared to the MELD era across all regions. A significantly elevated hazard of post-transplant mortality at 1 year was in the Medium group (HR: 1.487, P<0.0001) but not in the Low (HR: 1.145, P=0.425) or High groups (HR: 1.007, P=0.867) in the MELD-Na era. In the Medium group, the prevalence of diabetes, obesity, and primary diagnosis of NASH was significantly increased (P<0.0001, <0.0001, 0.0226, respectively) compared to Low and High groups. Overall, liver transplant survival benefit shifted towards a higher score category in the MELD-Na era in all groups. This change was more remarkable in the Medium group (6-11 to 15-17 in Low and High; 12-14 to 24-26 in the Medium group). Conclusion: This study demonstrates that while MELD-Na era reduced waitlist mortality overall, there are regional discrepancies in transplant mortality as well as survival benefit of transplant. Worse transplant outcomes were observed especially in the Medium group where metabolic syndrome significantly increased.