Reframing the impact of combined heart-liver allocation on liver transplant wait-list candidates

Simultaneous heart-liver (H-L) transplantation, although rare, has become more common in the United States. When the primary organ is a heart or liver, patients receiving an offer for the primary organ automatically receive the second, nonprimary organ from that donor. This policy raises issues of equity, such as whether liver transplantation alone candidates bypassed by H-L recipients are disadvantaged. No prior published analyses have addressed this issue, and few methods have been developed as means of measuring the impact of such allocation policies. We analyzed Organ Procurement and Transplantation Network match run data from 2007 to 2013 to determine whether this combined organ allocation policy disadvantages bypassed liver transplant wait-list candidates in a clinically meaningful way. Among 65 H-L recipients since May 2007, 42 had substantially higher priority for the heart versus the liver, and these 42 bypassed 268 liver-alone candidates ranked 1 to 10 on these match runs. Bypassed patients had a lower risk of wait-list removal for death or clinical deterioration in comparison with controls selected by the match Model for End-Stage Liver Disease (MELD) score [hazard ratio (HR) = 0.56, 95% confidence interval (CI) = 0.40-0.79] and a risk similar to that of controls selected by the laboratory MELD score (HR = 0.91, 95% CI = 0.63-1.33) or on match runs of similar graft quality (HR = 0.97, 95% CI = 0.73-1.37). The waiting time from bypass to subsequent transplantation was significantly longer among bypassed candidates versus controls on match runs of similar graft quality [median: 87 days (interquartile range = 27-192 days) versus 24 days (interquartile range = 5-79 days), P < 0.001]. Although transplantation was delayed, liver transplant wait-list candidates bypassed by H-L recipients did not have excess mortality in comparison with 3 sets of matched controls. These analytic methods serve as a starting point for considering other potential approaches to evaluating the impact of multiorgan transplant allocation policies.