Over 11,000 patients are listed annually for liver transplantation (LT) in the United States. However, nearly 3000 of these patients never undergo transplant.(1) It is crucial to optimize posttransplant outcomes for the recipient of each graft while minimizing wait-list mortality. This balance is complex and involves center-specific factors, including appropriate recipient identification, expeditious wait-listing, and effective care of wait-listed patients.
In the current issue, 2 important articles explore ways in which center-specific outcomes and patient allocation might be improved. Kwong et al. address a key metric to compare transplant centers: 1-year posttransplant survival.(2) Although this undoubtedly is an important individual patient outcome, it does not provide a complete picture of a center’s ability to guide wait-listed patients to transplant. Furthermore, tight clustering of 1-year posttransplant survival data makes it difficult to ascertain individual center quality. To address this issue, the authors evaluated an alternative metric, intention-to-treat survival, which captures 1-year patient survival beginning at wait-listing, regardless of whether transplantation is achieved. In an analysis of Scientific Registry of Transplant Recipients data from January 2010 to December 2016, the authors found that center-level variation in intention-to-treat survival was greater compared with posttransplant survival. Additionally, the individual center remained an independent predictor of intention-to-treat survival after adjustment for demographics and Model for End-Stage Liver Disease (MELD) score. These findings highlight intention-to-treat survival as a promising adjunctive metric by which center performance can be evaluated and ultimately optimized.
Although this is an important step toward reimagining center-specific outcomes and identifying areas for genuine quality improvement, it is critical to remember that intention-to-treat survival is still confined by being a wait-list metric. To properly account for center and regional performance, new models must capture events that occur prior to wait-listing itself. This may include, for example, the rate of transplant referrals among eligible patients with end-stage liver disease, timeliness of referrals, and time from referral to listing. Accounting for these factors explicitly acknowledges that many patients who may benefit from LT are never wait-listed, a clear opportunity for quality improvement.(3) Prior studies had uncovered significant geographic and racial inequities in access to LT using measures, such as the liver wait-listing ratio,(4) which evaluates wait-listing for a group relative to those potentially eligible for transplant. Therefore, the transplant community must also weigh the potential harms of instituting a metric such as intention-to-treat survival because center behavior may shift toward listing fewer patients in order to optimize this statistic. Ultimately, incorporation of metrics that span each phase of the transplantation process may provide the most complete picture of center performance to improve decision making and promote patient autonomy.
In the second article, Bajaj and Verna(5) address an allocation-related issue, namely, community perspectives on LT and prioritization of patients with acute-on-chronic liver failure (ACLF). There has been mounting evidence that patients diagnosed with ACLF, which carries an extremely high short-term mortality, are sicker than non-ACLF patients with an equivalent MELD score(6) and that these patients may have excellent posttransplant outcomes.(7,8) However, ACLF remains a controversial entity, which may be challenging to distinguish from acutely decompensated cirrhosis with multiple definitions and standards of assessment. The authors surveyed 80 health care LT clinicians about ACLF perspectives and case-based management decisions. Although most respondents agreed that ACLF patients warranted inpatient transplant workup, there was significant discordance in responses regarding the assignment of additional MELD points to ACLF patients, comfort with the use of living donor LT for ACLF, and even modest disagreement in the decision to proceed to deceased donor LT. The authors posited that the reasons for this response heterogeneity were multifactorial and include a lack of a unified ACLF definition, lack of specific biomarkers to differentiate the syndrome from acutely decompensated cirrhosis, and insufficient prospective data to justify a case for transplant prioritization.
More work is clearly needed to define the role and priority of LT for ACLF. As new measures are proposed to enhance our understanding of center performance, pretransplant and posttransplant outcomes, and patient decision making, it is imperative that these efforts are clearly designed and are advanced with the research community, clinicians, patients, and policymakers.
Acknowledgments
Marina Serper is supported by the National Institute of Diabetes and Digestive and Kidney Diseases award 1K23-DK-115897-03. Nadim Mahmud is supported by an American College of Gastroenterology Junior Faculty Development award ACG-JR-010-2020.
Abbreviations:
- ACLF
acute-on-chronic liver failure
- LT
liver transplantation
- MELD
Model for End-Stage Liver Disease
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