End-stage liver disease candidates at the highest model for end-stage liver disease scores have higher wait-list mortality than status-1A candidates

Abstract

Candidates with fulminant hepatic failure (Status-1A) receive the highest priority for liver transplantation (LT) in the United States. However, no studies have compared wait-list mortality risk among end-stage liver disease (ESLD) candidates with high Model for End-Stage Liver Disease (MELD) scores to those listed as Status-1A. We aimed to determine if there are MELD scores for ESLD candidates at which their wait-list mortality risk is higher than that of Status-1A, and to identify the factors predicting wait-list mortality among those who are Status-1A. Data were obtained from the Scientific Registry of Transplant Recipients for adult LT candidates (n = 52,459) listed between September 1, 2001, and December 31, 2007. Candidates listed for repeat LT as Status-1 A were excluded. Starting from the date of wait listing, candidates were followed for 14 days or until the earliest occurrence of death, transplant, or granting of an exception MELD score. ESLD candidates were categorized by MELD score, with a separate category for those with calculated MELD > 40. We compared wait-list mortality between each MELD category and Status-1A (reference) using time-dependent Cox regression. ESLD candidates with MELD > 40 had almost twice the wait-list mortality risk of Status-1A candidates, with a covariate-adjusted hazard ratio of HR = 1.96 (P = 0.004). There was no difference in wait-list mortality risk for candidates with MELD 36-40 and Status-1A, whereas candidates with MELD < 36 had significantly lower mortality risk than Status-1A candidates. MELD score did not significantly predict wait-list mortality among Status-1A candidates (P = 0.18). Among Status-1A candidates with acetaminophen toxicity, MELD was a significant predictor of wait-list mortality (P < 0.0009). Posttransplant survival was similar for Status-1A and ESLD candidates with MELD > 20 (P = 0.6).

Conclusion: Candidates with MELD > 40 have significantly higher wait-list mortality and similar posttransplant survival as candidates who are Status-1A, and therefore, should be assigned higher priority than Status-1A for allocation. Because ESLD candidates with MELD 36-40 and Status-1A have similar wait-list mortality risk and posttransplant survival, these candidates should be assigned similar rather than sequential priority for deceased donor LT.

Figure 1

MELD Score Distribution at Listing among ESLD and Status-1A Candidates Abbreviations: ESLD: End-Stage Liver Disease; MELD: Model for End-Stage Liver Disease

Figure 2

Kaplan-Meier wait-list survival curves for patients listed at Status-1A, MELD 36–40 and MELD >40. Abbreviations: MELD: Model for End-Stage Liver Disease

Figure 3

Comparing Covariate-adjusted Wait-list Mortality Risk between ESLD and Status-1A Candidates Status-1A is the reference group (hazard ratio set to 1). Compared to Status-1A, ESLD candidates with MELD score ≤35 have lower wait-list mortality risk; ESLD candidates with MELD score 36–40 have similar wait-list mortality risk; and ESLD candidates with MELD scores >40 have higher wait-list mortality risk. Abbreviations: MELD: Model for End Stage Liver Disease

Figure 4

Kaplan-Meier post-transplant survival curves for recipients transplanted at Status-1A, and MELD >20. Abbreviations: MELD: Model for End Stage Liver Disease

Figure 5

Comparing Covariate-adjusted Post-Transplant Mortality Risk between ESLD and Status-1A Candidates. Status-1A is the reference group (hazard ratio set to 1). Compared to Status-1A, ESLD candidates with MELD score ≤ 20 have lower overall post-transplant mortality risk; ESLD candidates with MELD scores 21–40 and >40 have similar post-transplant mortality risk. Abbreviations: ESLD: End Stage Liver Disease; MELD: Model for End Stage Liver Disease