Regional variability in liver waiting list removals causes false ascertainment of waiting list deaths

Sex-based Disparities in Hepatocellular Carcinoma Recurrence After Liver Transplantation

BACKGROUND

Women with chronic liver disease have lower rates of hepatocellular carcinoma (HCC) as compared to men; it is unknown if there are sex-based differences in HCC recurrence postliver transplant.

METHODS

We conducted an analysis of patients who underwent liver transplant for HCC in the United Network for Organ Sharing/Organ Procurement and Transplantation Network from January 1, 2012 through December 31, 2017.

RESULTS

A total of 12 711 patients underwent liver transplant for HCC: 2909 (23%) women and 9802 (73%) men. Women had significantly lower rates of postliver transplant HCC recurrence than men (4.0% versus 5.4%, P = 0.002). A cox-regression analysis for postliver transplant HCC recurrence highlighted that even after accounting for etiology of cirrhosis, alpha-fetoprotein at liver transplant, tumor diameter, tumor pathology, and vascular invasion, female sex was associated with a 25% lower risk of postliver transplant HCC recurrence (95% confidence interval: 0.57-0.99). There were no interactions between female sex and the following variables: age, type of locoregional therapy, alpha-fetoprotein, donor sex, body mass index, or nonalcoholic steatohepatitis etiology (P > 0.05 for each).

CONCLUSIONS

This study demonstrates an independent effect of sex on risk for HCC recurrence postliver transplant. Our data highlight an opportunity to better understand HCC tumor biology by investigating the drivers of this sex-based difference in HCC recurrence.

Do Social Determinants Define "Too Sick" to Transplant in Patients With End-stage Liver Disease?

BACKGROUND

Delisting for being "too sick" to be transplanted is subjective. Previous work has demonstrated that the mortality of patients delisted for "too sick" is unexpectedly low. Transplant centers use their best clinical judgment for determining "too sick," but it is unclear how social determinants influence decisions to delist for "too sick." We hypothesized that social determinants and Donor Service Area (DSA) characteristics may be associated with determination of "too sick" to transplant.

METHODS

Data were obtained from the Scientific Registry of Transplant Recipients for adults listed and removed from the liver transplant waitlist from 2002 to 2017. Patients were included if delisted for "too sick." Our primary outcome was Model for End-Stage Liver Disease (MELD) score at waitlist removal for "too sick." Regression assessed the association between social determinants and MELD at removal for "too sick."

RESULTS

We included 5250 delisted for "too sick" at 127 centers, in 53 DSAs, over 16 years. The mean MELD at delisting for "too sick" was 25.8 (SD ± 11.2). On adjusted analysis, social determinants including age, race, sex, and education predicted the MELD at delisting for "too sick" (P < 0.05).

CONCLUSIONS

There is variation in delisting MELD for "too sick" score across DSA and time. While social determinants at the patient and system level are associated with delisting practices, the interplay of these variables warrants additional research. In addition, center outcome reports should include waitlist removal rate for "too sick" and waitlist death ratios, so waitlist management practice at individual centers can be monitored.

New paradigms for organ allocation and distribution in liver transplantation

PURPOSE OF REVIEW

The 'Final Rule,' issued by the Health Resources and Service Administration in 2000, mandated that liver allocation policy should be based on disease severity and probability of death, and - among other factors - should be independent of a candidate's residence or listing. As a result, the Organ Procurement Transplantation Network/United Network for Organ Sharing (UNOS) has explored policy changes addressing geographic disparities without compromising outcomes.

RECENT FINDINGS

Major paradigm shifts are underway in U.S. liver allocation policy. New hepatocellular carcinoma exception policy incorporates tumor characteristics associated with posttransplantation outcomes, whereas a National Liver Review Board will promote a standardized process for awarding exception points. Meanwhile, following extensive debate, new allocation policy aims to reduce geographic disparity by broadening sharing to the UNOS region and 150-mile circle around the donor hospital for liver transplant candidates with a calculated model for end-stage liver disease score at least 32. Unnecessary organ travel will be reduced by granting 3 'proximity points' to candidates within the same donation service area (DSA) as a liver donor or within 150 nautical miles of the donor hospital, regardless of DSA or UNOS region.

SUMMARY

This review provides an evaluation of major policy changes in liver allocation from 2016 to 2018.

Sex-based disparities in delisting for being "too sick" for liver transplantation

Women with cirrhosis awaiting liver transplantation (LT) experience higher rates of waitlist mortality than men; it is unknown whether practices surrounding delisting for being "too sick" for LT contribute to this disparity beyond death alone. We conducted an analysis of patients listed for LT in the United Network for Organ Sharing/Organ Procurement and Transplantation Network not receiving exception points from May 1, 2007 to July 1, 2014 with a primary outcome of delisting with removal codes of "too sick" or "medically unsuitable." A total of 44 388 patients were included; 4458 were delisted for being "too sick" for LT. Delisting was more frequent in women (11% vs 9%, P < .001). Compared to delisted men, delisted women differed in age (58 vs 57), non-hepatitis C virus listing diagnoses (69% vs 56%), hepatic encephalopathy (36% vs 31%), height (161.9 vs 177.0 cm), private insurance (47% vs 52%), and Karnofsky performance status (60 vs 70) (P < .001 for all). There were no differences in Model for End-Stage Liver Disease including serum sodium and Child Pugh Scores. A competing risk analysis demonstrated that female sex was independently associated with a 10% (confidence interval 2%-18%) higher risk of delisting when accounting for rates of death and transplantation and adjusting for confounders. This study demonstrates a significant disparity in delisting practices by sex, highlighting the need for better assessments of sickness, particularly in women.

Attitudes and barriers to the use of donation after cardiac death livers: Comparison of a United States transplant center survey to the united network for organ sharing data

Transplantation of liver grafts from donation after cardiac death (DCD) is limited. To identify barriers of DCD liver utilization, all active US liver transplant centers (n = 138) were surveyed, and the responses were compared with the United Network for Organ Sharing (UNOS) data. In total, 74 (54%) centers responded, and diversity in attitudes was observed, with many not using organ and/or recipient prognostic variables defined in prior studies and UNOS data analysis. Most centers (74%) believed lack of a system allowing a timely retransplant is a barrier to utilization. UNOS data demonstrated worse 1- and 5-year patient survival (PS) and graft survival (GS) in DCD (PS, 86% and 64%; GS, 82% and 59%, respectively) versus donation after brain death (DBD) recipients (PS, 90% and 71%; GS, 88% and 69%, respectively). Donor alanine aminotransferase (ALT), recipient Model for End-Stage Liver Disease (MELD), and cold ischemia time (CIT) significantly impacted DCD outcomes to a greater extent than DBD outcomes. At 3 years, relisting and retransplant rates were 7.9% and 4.6% higher in DCD recipients. To optimize outcome, our data support the use of DCD liver grafts with CIT <6-8 hours in patients with MELD ≤ 20. In conclusion, standardization of donor and recipient criteria, defining the impact of ischemic cholangiopathy, addressing donor hospital policies, and developing a strategy for timely retransplant may help to expand the use of these organs. Liver Transplantation 23 1372-1383 2017 AASLD.

Sociodemographic Determinants of Waitlist and Posttransplant Survival Among End-Stage Liver Disease Patients

While regional organ availability dominates discussions of distribution policy, community-level disparities remain poorly understood. We studied micro-geographic determinants of survival risk and their distribution across Donor Service Areas (DSAs). Scientific Registry of Transplant Recipients records for all adults waitlisted for liver transplantation 2002-2014 were reviewed. The primary exposure variables were county-level sociodemographic risk, as measured by the Community Health Score (CHS), a previously-validated composite index local health conditions, and distance to listing transplant center. Among 114 347 patients, the median CHS was 19.4 (range: 0-40). Compared the lowest risk counties (CHS 1-10), highest-risk counties (CHS 31-40) had more black (14.6% vs. 5.4%), publicly insured (44.9% vs. 33.0), and remote candidates (34.0% vs. 15.1% living >100 miles away). Higher-CHS candidates had greater waitlist mortality in Cox multivariable (HR 1.16 for CHS 31-40, 95% CI 1.11-1.21) and competing risks analysis (sHR 1.07, 95% CI 0.99-1.14). Post-transplant survival was similar across CHS quartiles. Living >25 miles from the transplant center conferred excess mortality risk (sHR 1.08, 95% CI 1.03-1.12). Proposed distribution changes would disproportionately impact DSAs with more high-CHS or distant candidates. Low-income, rural and minority patients experience excess mortality while awaiting transplant, and risk disproportionately worse outcomes with reduced organ availability under current proposals.

Decade-Long Trends in Liver Transplant Waitlist Removal Due to Illness Severity: The Impact of Centers for Medicare and Medicaid Services Policy

BACKGROUND

The central tenet of liver transplant organ allocation is to prioritize the sickest patients first. However, a 2007 Centers for Medicare and Medicaid Services regulatory policy, Conditions of Participation (COP), which mandates publically reported transplant center performance assessment and outcomes-based auditing, critically altered waitlist management and clinical decision making. We examine the extent to which COP implementation is associated with increased removal of the "sickest" patients from the liver transplant waitlist.

STUDY DESIGN

This study included 90,765 adult (aged 18 years and older) deceased donor liver transplant candidates listed at 102 transplant centers from April 2002 through December 2012 (Scientific Registry of Transplant Recipients). We quantified the effect of COP implementation on trends in waitlist removal due to illness severity and 1-year post-transplant mortality using interrupted time series segmented Poisson regression analysis.

RESULTS

We observed increasing trends in delisting due to illness severity in the setting of comparable demographic and clinical characteristics. Delisting abruptly increased by 16% at the time of COP implementation, and likelihood of being delisted continued to increase by 3% per quarter thereafter, without attenuation (p < 0.001). Results remained consistent after stratifying on key variables (ie, Model for End-Stage Liver Disease and age). The COP did not significantly impact 1-year post-transplant mortality (p = 0.38).

CONCLUSIONS

Although the 2007 Centers for Medicare and Medicaid Services COP policy was a quality initiative designed to improve patient outcomes, in reality, it failed to show beneficial effects in the liver transplant population. Patients who could potentially benefit from transplantation are increasingly being denied this lifesaving procedure while transplant mortality rates remain unaffected. Policy makers and clinicians should strive to balance candidate and recipient needs from a population-benefit perspective when designing performance metrics and during clinical decision making for patients on the waitlist.

Keeping high model for end-stage liver disease score liver transplantation candidates alive

As the mean Model for End-Stage Liver Disease (MELD) score at time of liver transplantation continues to increase, it is crucial to implement preemptive strategies to reduce wait-list mortality. We review the most common complications that arise in patients with a high MELD score in an effort to highlight strategies that can maximize survival and successful transplantation.

High risk of delisting or death in liver transplant candidates following infections: Results from the North American Consortium for the Study of End-Stage Liver Disease

Because Model for End-Stage Liver Disease (MELD) scores at the time of liver transplantation (LT) increase nationwide, patients are at an increased risk for delisting by becoming too sick or dying while awaiting transplantation. We quantified the risk and defined the predictors of delisting or death in patients with cirrhosis hospitalized with an infection. North American Consortium for the Study of End-Stage Liver Disease (NACSELD) is a 15-center consortium of tertiary-care hepatology centers that prospectively enroll and collect data on infected patients with cirrhosis. Of the 413 patients evaluated, 136 were listed for LT. The listed patients' median age was 55.18 years, 58% were male, and 47% were hepatitis C virus infected, with a mean MELD score of 2303. At 6-month follow-up, 42% (57/136) of patients were delisted/died, 35% (47/136) underwent transplantation, and 24% (32/136) remained listed for transplant. The frequency and types of infection were similar among all 3 groups. MELD scores were highest in those who were delisted/died and were lowest in those remaining listed (25.07, 24.26, 17.59, respectively; P < 0.001). Those who were delisted or died, rather than those who underwent transplantation or were awaiting transplantation, had the highest proportion of 3 or 4 organ failures at hospitalization versus those transplanted or those continuing to await LT (38%, 11%, and 3%, respectively; P = 0.004). For those who were delisted or died, underwent transplantation, or were awaiting transplantation, organ failures were dominated by respiratory (41%, 17%, and 3%, respectively; P < 0.001) and circulatory failures (42%, 16%, and 3%, respectively; P < 0.001). LT-listed patients with end-stage liver disease and infection have a 42% risk of delisting/death within a 6-month period following an admission. The number of organ failures was highly predictive of the risk for delisting/death. Strategies focusing on prevention of infections and extrahepatic organ failure in listed patients with cirrhosis are required.

Pretransplant replacement of donor liver grafts with recipient Kupffer cells attenuates liver graft rejection in rats

BACKGROUND AND AIM

Rejection of liver grafts is a difficult issue that has not been resolved. Preoperative replacement of liver cells in the graft with cells from the intended recipient may attenuate rejection. We investigated whether preoperative transplant of recipient bone marrow cells (BMCs) to the donor replaced liver allograft cells and attenuated rejection.

METHODS

We used a rat model of allogeneic liver transplant (LT) from Dark Agouti (DA) to Lewis (LEW) rats. In BMC group, DA rats received BMC transplants from LacZ-transgenic LEW rats at 1 week before LT. In the control group, DA rats received no preoperative treatment. We evaluated graft damage at 7 days after LT and the survival of the recipient rats.

RESULTS

Rats in the BMC group experienced prolonged survival that was abrogated by the administration of gadolinium chloride to donors at 24 h before LT. Serum concentrations of total bilirubin and hyaluronic acid on day 7 were significantly lower in the BMC group, and histopathological analyses revealed that rejection of the liver graft was attenuated. X-gal staining and immunohistostaining of the liver graft revealed that BMCs engrafted in the sinusoidal space differentiated into Kupffer cells.

CONCLUSIONS

Preoperative transplant of recipient BMCs to LT donors replaced donor Kupffer cells and attenuated post-LT rejection, indicating that this strategy may increase the success of LT.

Serum hypoalbuminemia predicts late mortality on the liver transplant waiting list

BACKGROUND

The reduction of liver transplant wait list mortality remains a priority for transplant programs and depends on the accurate stratification of patients by mortality risk. Although estimation of 90-day mortality by Model for End-Stage Liver Disease (MELD) score has improved wait list survival, it is unclear how contemporary wait list mortality can best be diminished given the preponderance of listed patients with low MELD scores and long wait times.

METHODS

In this intention-to-treat analysis of 289 consecutively listed patients with over 5 years of follow-up, we aimed to determine the contribution of late mortality to overall wait list outcome and identify clinical predictors that would help discriminate long-term survivors from fatalities.

RESULTS

Seventy percent of wait list deaths occurred in patients listed with MELD scores less than 20, and 40% of deaths occurred in patients waiting longer than 1 year. Hypoalbuminemia at listing was a significant predictor of late mortality in all patients in both univariate and multivariate analyses, and it was most discriminatory among patients with MELD scores of 20 or less.

CONCLUSION

Our data suggest that hypoalbuminemia at listing reveals a vulnerable population of low MELD patients who are underserved by their MELD score over time. Such patients comprise almost 40% of the contemporary wait list and contribute substantially to list mortality given their poor access to transplantation. Targeting these at-risk patients with grafts from living or extended criteria donors may thus significantly diminish overall list mortality, and future initiatives to decrease overall wait list mortality must focus on improved risk stratification for low MELD patients.