MELD scores of liver transplant recipients according to size of waiting list: impact of organ allocation and patient outcomes

Racial disparities in posttransplant outcomes among recipients undergoing simultaneous liver-kidney transplantation

BACKGROUND

Patients with end-stage cirrhosis may experience renal dysfunction, necessitating a simultaneous kidney-liver transplant (SKLT). Guidelines have been put forth by the United Network for Organ Sharing (UNOS) to streamline the SKLT allocation process and ensure equitable access to transplantation. However, there is a scarcity of literature on racial and ethnic disparities in post-SKLT outcomes.

METHODS

The UNOS Standard Transplant Analysis and Research Database was queried from 2005 to 2019 to study SKLT patients. Patients were stratified by race: White (reference group) recipients (n = 3513), Black recipients (n = 859), Hispanic recipients (n = 964), Asian recipients (n = 206), and other recipients (n = 85). Primary endpoints included all-cause mortality and graft failure while secondary endpoints were specific causes of death.

RESULTS

Hispanic recipients had a lower risk of all-cause mortality (aHR: 0.79, 95% CI: 0.68-0.93, P = 0.003), while Black recipients had a significantly increased risk of graft failure compared to Whites (aHR: 1.63, 95% CI: 1.16-2.30, P = 0.005). Evaluation of specific causes of recipient death revealed a higher risk of death due to gastrointestinal hemorrhage among Blacks (aHR: 4.16, 95% CI: 1.04-16.68, P = 0.04).

CONCLUSION

Our study findings show Black patients experience higher rates of graft failure compared to White counterparts. The reasons for these disparities are not fully understood but likely a combination of biological and social factors. Further investigation is warranted to ascertain the specific factors influencing these outcomes.

Differential Effects of Ascites and Hepatic Encephalopathy on Waitlist Mortality in Liver Transplantation by MELD 3.0

Background

MELD 3.0 introduces changes to address waitlist disparities for liver transplant (LT) candidates. Ascites and hepatic encephalopathy (HE) are important milestones in the natural history of cirrhosis regardless of the Model for End-Stage Liver Disease (MELD) score. We aim to assess the impact of ascites and HE and its interaction with MELD 3.0 on waitlist mortality.

Methods

This is a retrospective study of patients listed for LT in the Organ Procurement and Transplantation Network database from 2016 to 2021. The primary outcome was waitlist mortality (death/delisting for too sick to LT). Ascites/HE were classified as moderate ascites without moderate HE (mAscites), moderate HE without moderate ascites (mHE), both moderate ascites/HE (mBoth), and neither. MELD 3.0 scores were categorized as <20, 20-29, 30-39, and ≥40.

Results

Of 39 025 candidates, 29% had mAscites, 3% mHE, and 8% mBoth. One-year waitlist mortality was 30%, 38%, and 47%, respectively, compared with 17% (all P < 0.001) for those with neither. In multivariable Cox regression, the adjusted risk of waitlist mortality associated with mAscites (versus neither) was a hazard ratio (HR) of 1.76 (95% confidence interval [CI], 1.55-2.00) when the MELD 3.0 score was <20, significantly higher than when the MELD 3.0 score was 20-29 (HR 1.40; 95% CI, 1.27-1.54), 30-39 (HR 1.19; 95% CI, 1.04-1.35), and ≥40 (HR 1.14; 95% CI, 0.91-1.43, interaction P < 0.05 for all). A similar pattern was observed by MELD 3.0 for both moderate ascites/HE.

Conclusions

The presence of moderate ascites alone, or combined with moderate HE, not only increases the risk of waitlist mortality but also has a differential effect by MELD 3.0, especially at lower MELD scores. Earlier strategies addressing this group and improving treatment plans or access to LT regardless of MELD remain needed.

MELD 3.0 in Advanced Chronic Liver Disease

The MELD (model for end-stage liver disease) 3.0 score was developed to replace the MELD-Na score that is currently used to prioritize liver allocation for cirrhotic patients awaiting liver transplantation in the United States. The MELD 3.0 calculator includes new inputs from patient sex and serum albumin levels and has new weights for serum sodium, bilirubin, international normalized ratio, and creatinine levels. It is expected that use of MELD 3.0 scores will reduce overall waitlist mortality modestly and improve access for female liver transplant candidates. The utility of MELD 3.0 and PELDcre (pediatric end-stage liver disease, creatinine) scores for risk stratification in cirrhotic patients undergoing major abdominal surgery, placement of a transjugular intrahepatic portosystemic shunt, and other interventions requires further study. This article reviews the background of the MELD score and the rationale to create MELD 3.0 as well as potential implications of using this newer risk stratification tool in clinical practice.

Role of Quantitation of Saline Bubble Studies in Patients with Liver Cirrhosis

OBJECTIVE

Microbubble contrast echocardiography with a late positive signal enables the detection of intrapulmonary vascular dilation, including hepatopulmonary syndrome, in patients with end-stage liver disease. We assessed the relationship between the severity of bubble study and clinical outcome.

METHODS

We retrospectively analyzed 163 consecutive patients with liver cirrhosis who underwent an echocardiogram with bubble study from 2018 to 2021. Patients who were diagnosed with a late positive signal were divided into three groups: grade 1 (1-9 bubbles), grade 2 (10-30 bubbles) and grade 3 (>30 bubbles).

RESULTS

Fifty-six percent of the patients had a late positive bubble study (grade 1: 31%, grade 2: 23%, grade 3: 46%). Patients with grade 3 had a significantly higher international normalized ratio, model for end-stage liver disease score and Child-Pugh score and a lower peripheral oxygen saturation compared with patients with a negative study. In patients undergoing liver transplant (LT), survival rates were similar among the groups (3-mo: >87%, 1-y: >87%, 2-y: >83%). However, survival rate was lower in grade 3 patients without LT (3-mo: 81%, 1-y: 64%, 2-y: 39%).

CONCLUSION

Patients with grade 3 had much worse mortality without LT compared with other groups. However, after LT, all grades had equal survival. Therefore, patients with grade 3 may be considered as higher priority for LT.

County-level Differences in Liver-related Mortality, Waitlisting, and Liver Transplantation in the United States

BACKGROUND

Much of our understanding regarding geographic issues in transplantation is based on statistical techniques that do not formally account for geography and is based on obsolete boundaries such as donation service area.

METHODS

We applied spatial epidemiological techniques to analyze liver-related mortality and access to liver transplant services at the county level using data from the Centers for Disease Control and Prevention and Scientific Registry of Transplant Recipients from 2010 to 2018.

RESULTS

There was a significant negative spatial correlation between transplant rates and liver-related mortality at the county level (Moran's I, -0.319; P  = 0.001). Significant clusters were identified with high transplant rates and low liver-related mortality. Counties in geographic clusters with high ratios of liver transplants to liver-related deaths had more liver transplant centers within 150 nautical miles (6.7 versus 3.6 centers; P  < 0.001) compared with all other counties, as did counties in geographic clusters with high ratios of waitlist additions to liver-related deaths (8.5 versus 2.5 centers; P  < 0.001). The spatial correlation between waitlist mortality and overall liver-related mortality was positive (Moran's I, 0.060; P  = 0.001) but weaker. Several areas with high waitlist mortality had some of the lowest overall liver-related mortality in the country.

CONCLUSIONS

These data suggest that high waitlist mortality and allocation model for end-stage liver disease do not necessarily correlate with decreased access to transplant, whereas local transplant center density is associated with better access to waitlisting and transplant.

Predicting mortality among patients with liver cirrhosis in electronic health records with machine learning

OBJECTIVE

Liver cirrhosis is a leading cause of death and effects millions of people in the United States. Early mortality prediction among patients with cirrhosis might give healthcare providers more opportunity to effectively treat the condition. We hypothesized that laboratory test results and other related diagnoses would be associated with mortality in this population. Our another assumption was that a deep learning model could outperform the current Model for End Stage Liver disease (MELD) score in predicting mortality.

MATERIALS AND METHODS

We utilized electronic health record data from 34,575 patients with a diagnosis of cirrhosis from a large medical center to study associations with mortality. Three time-windows of mortality (365 days, 180 days and 90 days) and two cases with different number of variables (all 41 available variables and 4 variables in MELD-NA) were studied. Missing values were imputed using multiple imputation for continuous variables and mode for categorical variables. Deep learning and machine learning algorithms, i.e., deep neural networks (DNN), random forest (RF) and logistic regression (LR) were employed to study the associations between baseline features such as laboratory measurements and diagnoses for each time window by 5-fold cross validation method. Metrics such as area under the receiver operating curve (AUC), overall accuracy, sensitivity, and specificity were used to evaluate models.

RESULTS

Performance of models comprising all variables outperformed those with 4 MELD-NA variables for all prediction cases and the DNN model outperformed the LR and RF models. For example, the DNN model achieved an AUC of 0.88, 0.86, and 0.85 for 90, 180, and 365-day mortality respectively as compared to the MELD score, which resulted in corresponding AUCs of 0.81, 0.79, and 0.76 for the same instances. The DNN and LR models had a significantly better f1 score compared to MELD at all time points examined.

CONCLUSION

Other variables such as alkaline phosphatase, alanine aminotransferase, and hemoglobin were also top informative features besides the 4 MELD-Na variables. Machine learning and deep learning models outperformed the current standard of risk prediction among patients with cirrhosis. Advanced informatics techniques showed promise for risk prediction in patients with cirrhosis.

Evolution of liver transplant organ allocation policy: Current limitations and future directions

Since the adoption of the model for end-stage liver disease (MELD) score for organ allocation in 2002, numerous changes to the system of liver allocation and distribution have been made with the goal of decreasing waitlist mortality and minimizing geographic variability in median MELD score at time of transplant without worsening post-transplant outcomes. These changes include the creation and adoption of the MELD-Na score for allocation, Regional Share 15, Regional Share for Status 1, Regional Share 35/National Share 15, and, most recently, the Acuity Circles Distribution Model. However, geographic differences in median MELD at time of transplant remain as well as limits to the MELD score for allocation, as etiology of liver disease and need for transplant changes. Acute-on-chronic liver failure (ACLF) is a subset of liver failure where prevalence is rising and has been shown to have an increased mortality rate and need for transplantation that is under-demonstrated by the MELD score. This underscores the limitations of the MELD score and raises the question of whether MELD is the most accurate, objective allocation system. Alternatives to the MELD score have been proposed and studied, however MELD score remains as the current system used for allocation. This review highlights policy changes since the adoption of the MELD score, addresses limitations of the MELD score, reviews proposed alternatives to MELD, and examines the specific implications of these changes and alternatives for ACLF.

Recipient risk factors for acute cellular rejection after orthotopic liver transplant - a single-center, retrospective study

The use of model for end-stage liver disease (MELD) score for liver allocation has resulted in transplanting sicker patients. As such, it is unclear whether the risk factors and severity of acute cellular rejection (ACR) have changed. To identify ACR characteristics where average MELD score at transplant is higher than previously published studies. This is a single-center, retrospective study designed to assess risk factors associated with ACR after adult orthotopic liver transplant (OLT) using a steroid sparing regimen. This study included 174 OLT patients transplanted from 2008 to 2013 at a single tertiary care center. Recipient demographics, preoperative clinical, and laboratory data were recorded for each transplant. Univariate and multivariate regression analyses were performed to identify variables that are significant predictors for ACR. The median MELD at transplantation was 29.5. The average time from transplant to ACR diagnosis was 283.9 days and a majority of ACR episodes were mild to moderate. Serum creatinine, primary sclerosing cholangitis etiology, and tacrolimus use were significant predictors for ACR (P < 0.05). This study confirmed a change in timing and severity of ACR in the MELD era. Recipient characteristics may affect the risk for developing ACR and should be considered when managing immunosuppression.

A Comprehensive Review of Outcome Predictors in Low MELD Patients

Risk scoring for patients with cirrhosis has evolved greatly over the past several decades. However, patients with low Model for End-Stage Liver Disease-Sodium scores still suffer from liver-related morbidity and mortality. Unfortunately, it is not clear which of these low Model for End-Stage Liver Disease-Sodium score patients would benefit from earlier consideration of liver transplantation. This article reviews the literature of risk prediction in patients with cirrhosis, identifies which patients may benefit from earlier interventions, such as transplantation, and proposes directions for future research.

Persistent sex disparity in liver transplantation rates

BACKGROUND

Studies have demonstrated that there are sex disparities in the rate of liver transplantation. However, little is known statistically about whether this disparity is caused by liver compartment size, Model for End-Stage Liver Disease adjustments, or regional differences.

METHODS

We use retrospective data from the United Network for Organ Sharing Standard Treatment Analysis and Research data files for liver transplantation from 1995 through 2012. The final sample consists of 150,149 patients. These data contain information on all individuals who registered for the liver transplant waiting list as well as updated outcome data. Linear probability and logistic regression models were both used.

RESULTS

Women were 4.8 percentage points less likely to receive a transplant. Adjustment for race, weight, body mass index, region, education, and other characteristics attenuated the sex difference by roughly 19% (from 4.8 to 3.9 percentage points). The disparity was consistent across the 11 United Network for Organ Sharing allocation regions. Comparing the heaviest women to the lightest men, the disparity flipped. Pairwise comparisons between men and women of various sizes suggest that disparities in favor of men increase with the ratio of male-to-female size.

CONCLUSION

Our results document persistent sex disparity in liver transplantation, only 19% of which is explained by size differentials between men and women. Differences in rates of transplantation are increasing in the ratio of male-to-female height and weight, suggesting that some of the disparity is explained by differences in liver compartment size.

Patients With Persistently Low MELD-Na Scores Continue to Be at Risk of Liver-related Death

BACKGROUND

The vast majority of patients with cirrhosis have low Model for End-Stage Liver Disease-Sodium (MELD-Na) scores; however, the ability for the MELD-Na score to predict patient outcomes at low scores is unclear.

METHODS

Adult patients in a multicenter, Chicago-wide database of medical records with International Classification of Disease, Ninth Edition codes of cirrhosis and without a history of hepatocellular carcinoma were included. Records were linked with the state death registry, and death certificates were manually reviewed. Deaths were classified as "liver-related," "non-liver-related," and "non-descript" as adjudicated by a panel comprised of a transplant surgeon, a hepatologist, and an internist. A sensitivity analysis was performed where patients with hepatocellular carcinoma were included.

RESULTS

Among 7922 identified patients, 3999 patients had MELD-Na scores that were never higher than 15. In total, 2137 (27%) patients died during the study period with higher mortality rates for the patients in the high MELD-Na group (19.4 (41.6%) versus 4.1 (12.6%) per 100 person-y, P < 0.001). The high MELD-Na group died of a liver-related cause in 1142 out of 1632 (70%) as compared to 240 out of 505 (47.5%) deaths in the low MELD-Na group. There was no difference in the distribution of subcategory of liver-related death between low and high MELD-Na groups. Among subclassification of liver-related deaths, the most common cause of death was "Infectious" in both groups.

CONCLUSIONS

Despite persistently low MELD-Na scores, patients with cirrhosis still experience high rates of liver-related mortality.

Geographic Disparities in Liver Allocation and Distribution in the United States: Where Are We Now?

BACKGROUND

Equitable deceased donor liver allocation and distribution has remained a heated topic in transplant medicine. Despite the establishment of numerous policies, mixed reports regarding organ allocation persist.

METHODS

Patient data was obtained from the United Network for Organ Sharing liver transplant database between January 2016 and September 2017. A total of 20,190 patients were included in the analysis. Of this number, 8790 transplanted patients had a median Model for End-Stage Liver Disease (MELD) score of 25 (17-33), after a wait time of 129 (32-273) days. Patients were grouped into low MELD and high MELD regions using a score 25 as the cutoff.

RESULTS

Significant differences were noted between low and high MELD regions in ethnicity (white 77.4% vs 60.4%, Hispanic 8.1% vs 24.5%; P < .001) and highest level of education (grade school 4.8% vs 8.5%, Associate/Bachelor's degree 19% vs 15.7%, P < .001), respectively. Patients in high MELD regions were more likely to be multiply listed if they had a diagnosis of hepatocellular carcinoma (12.1% vs 15%, P = .046). Wait-list mortality (4.8% vs 6%, P < .001) and wait-list time (110 [27-238] vs 156 [42-309] days, P < .001) were greater in the high MELD regions.

CONCLUSIONS

These results highlight some of the existing disparities in the recently updated allocation and distribution policy of deceased donor livers. Our findings are consistent with previous work and support the liver distribution policy revision.

[Liver transplants and organ allocation in Brazil: from Rawls to utilitarianism]

The process of liver donations and transplants in Brazil reveals major inequalities between regions and states of the country, ranging from uptake of the organs to their transplantation. In 2006, the MELD score (Model for End-stage Liver Disease), inspired by the U.S. model and based on the principle of need, was introduced in Brazil for liver transplant allocation. However, Brazil's inequalities have partially undermined the initiative's success. Other countries have already benefited from growing discussion on the benefits of models that seek to harmonize utilitarianism and need. The current article reviews the relevant literature with a special focus on the Brazilian reality.

County socioeconomic characteristics and pediatric renal transplantation outcomes

BACKGROUND

Existing risk adjustment models for solid organ transplantation omit socioeconomic status (SES). With limited data available on transplant candidates' SES, linkage of transplant outcomes data to geographic SES measures has been proposed. We investigate the utility of county SES for understanding differences in pediatric kidney transplantation (KTx) outcomes.

METHODS

We identified patients < 18 years of age receiving first-time KTx using United Network for Organ Sharing registry data in two eras: 2006-2010 and 2011-2015, corresponding to periods of county SES data collection. In each era, counties were ranked by 1-year rates of survival with intact graft, and by county SES score. We used Spearman correlation (ρ) to evaluate the association between county rankings on SES and transplant outcomes in each era and consistency between these measures across eras. We also evaluated the utility of county SES for improving prediction of individual KTx outcomes.

RESULTS

The analysis included 2972 children and 108 counties. County SES and transplant outcomes were not correlated in either 2006-2010 (ρ = 0.06; p = 0.525) or 2011-2015 (ρ = 0.162, p = 0.093). County SES rankings were strongly correlated between eras (ρ = 0.99, p < 0.001), whereas county rankings of transplant outcomes were not correlated between eras (ρ = 0.16, p = 0.097). Including county SES quintile in individual-level models of transplant outcomes did not improve model predictive utility.

CONCLUSIONS

Pediatric kidney transplant outcomes are unstable from period to period at the county level and are not correlated with county-level SES. Appropriate adjustment for SES disparities in transplant outcomes could require further collection of detailed individual SES data.

The Impact of Share 35 Policy on Patient Survival in Patients Undergoing Liver Transplantation With Gender- and Race-Mismatched Donors: An Analysis of the United Network for Organ Sharing Registry

INTRODUCTION

The United Network for Organ Sharing (UNOS) instituted the Share 35 policy in June 2013 in order to reduce death on liver transplant waitlist. The effect of this policy on patient survival among patients with gender- and race-mismatched donors has not been examined.

RESEARCH QUESTION

To assess the impact of Share 35 policy on posttransplantation patient survival among patients with end-stage liver disease (ESLD) transplanted with gender- and race-mismatched donors.

DESIGN

A total of 16 467 adult patients with ESLD who underwent liver transplantation between 2012 and 2015 were identified from UNOS. An overall Cox proportional hazards model adjusting for demographic, clinical, and geographic factors and separate models with a dummy variable of pre- and post-Share 35 periods as well as its interaction with other factors were performed to model the effect of gender and race mismatch on posttransplantation patient survival and to compare the patient survival differences between the first 18 months of Share 35 policy to an equivalent time period before.

RESULTS

Comparison of the pre- and post-Share 35 periods did not show significant changes in the numbers of gender- and race-mismatched transplants, or the risk of death for gender-mismatched recipients. However, black recipients with Hispanic donors (hazard ratio: 0.51, 95% confidence interval, 0.29-0.90) had significantly increased patient survival after Share 35 policy took effect.

CONCLUSION

The Share 35 policy had a moderate impact on posttransplantation patient survival among recipients with racially mismatched donors according to the first 18-month experience. Future research is recommended to explore long-term transplantation.

Improvement in the Outcomes of MELD ≥ 40 Liver Transplantation: An Analysis of 207 Consecutive Transplants in a Highly Competitive DSA

BACKGROUND

Organ donor shortages continue to persist, especially in regions of the United States where competition is highest and recipients frequently attain a Model for End-Stage Liver Disease (MELD) score of 40 or higher before transplantation. The benefits of Share 35 in highly competitive regions may be underestimated when examining the collective national experience. The purpose of this study was to examine the outcomes of liver transplantation in recipients with a MELD of 40 or higher after implementation of Share 35 in a single center located in region 5.

METHODS

The method used in this study was single-center retrospective analysis of 207 liver transplant recipients who achieved MELD score of 40 or higher from April 21, 2002, to May 15, 2015.

RESULTS

Multivariable analysis identified implementation of Share 35 as the strongest predictor of graft survival in MELD of 40 or higher liver transplantation. The post-Share 35, 1-year graft survival was 94% compared with 75% pre-Share 35 (P = 0.002). Post-Share 35 recipients waited significantly less time until transplantation (10 vs 16 days, P = 0.015), and fewer were hospitalized for more than 28 days before their transplant (6% vs 18%, P = 0.05). Multivariable analysis identified recipients with diabetes at the time of listing as the strongest predictor of posttransplant patient mortality.

CONCLUSIONS

Implementation of the Share 35 allocation policy has a significant effect on outcomes by improving organ access and minimizing candidate waiting times. Recipients achieving a MELD of 40 or higher at our center post-Share 35 had an improved 1-year graft survival. However, nearly 40% remained hospitalized for more than 4 weeks posttransplant, and 20% were discharged to an acute care facility.

The postoperative Model for End stage Liver Disease score as a predictor of short-term outcome after transplantation of extended criteria donor livers

BACKGROUND

Recently, the postoperative Model for End stage Liver Disease score (POPMELD) was suggested as a definition of postoperative graft dysfunction and a predictor of outcome after liver transplantation (LT).

AIM

The aim of the present study was to validate this concept in the context of extended criteria donor (ECD) organs.

PATIENTS AND METHODS

Single-center prospectively collected data (OPAL study/01/11-12/13) of 116 ECD LTs were utilized. For each recipient, the Model for End stage Liver Disease (MELD) score was calculated for 7 postoperative days (PODs). The ability of international normalized ratio, bilirubin, aspartate aminotransferase, Donor Risk Index, a recent definition of early allograft dysfunction, and the POPMELD was compared to predict 90-day graft loss. Predictive abilities were compared by receiver operating characteristic curves, sensitivity and specificity, and positive and negative predictive values.

RESULTS

The median Donor Risk Index was 1.8. In all, 60.3% of recipients were men [median age of 54 (23-68) years]. The median POD1-7 peak-aspartate aminotransferase value was 1052 (194-17 577) U/l. The rate of early allograft dysfunction was 22.4%. The 90-day graft survival was 89.7%. Out of possible predictors of the 90-day graft loss MELD on POD5 was the best predictor of outcome (area under the curve=0.84). A MELD score of 16 or more on POD5 predicted the 90-day graft loss with a specificity of 80.8%, a sensitivity of 81.8%, and a positive and negative predictive value of 31 and 97.7%.

CONCLUSION

A MELD score of 16 or more on POD5 is an excellent predictor of outcome in ECD donor LT. Routine evaluation of POPMELD scores might support clinical decision-making and should be reported routinely in clinical trials.

Predicting Outcomes on the Liver Transplant Waiting List in the United States: Accounting for Large Regional Variation in Organ Availability and Priority Allocation Points

BACKGROUND

The probability of liver transplant and death on the waiting list in the United States varies greatly by donation service area (DSA) due to geographic differences in availability of organs and allocation of priority points, making it difficult for providers to predict likely outcomes after listing. We aimed to develop an online calculator to report outcomes by region and patient characteristics.

METHODS

Using the Scientific Registry of Transplant Recipients database, we included all prevalent US adults aged 18 years or older waitlisted for liver transplant, examined on 24 days at least 30 days apart over a 2-year period. Outcomes were determined at intervals of 30 to 365 days. Outcomes are reported by transplant program, DSA, region, and the nation for comparison, and can be shown by allocation or by laboratory model for end-stage liver disease (MELD) score (6-14, 15-24, 25-29, 30-34, 35-40), age, and blood type.

RESULTS

Outcomes varied greatly by DSA; for candidates with allocation MELD 25-29, the 25th and 75th percentiles of liver transplant probability were 30% and 67%, respectively, at 90 days. Corresponding percentiles for death or becoming too sick to undergo transplant were 5% and 9%. Outcomes also varied greatly for candidates with and without MELD exception points.

CONCLUSIONS

The waitlist outcome calculator highlights ongoing disparities in access to liver transplant and may assist providers in understanding and counseling their patients about likely outcomes on the waiting list.

Race/Ethnicity-Specific Outcomes Among Chronic Hepatitis C Virus Patients Listed for Liver Transplantation

BACKGROUND

Chronic hepatitis C virus (HCV) infection is a leading cause of hepatocellular carcinoma (HCC) and need for liver transplantation (LT). It is unclear if HCV-related LT outcomes vary by race/ethnicity.

AIMS

We aim to evaluate ethnic disparities specifically among patients with chronic HCV in the USA.

METHODS

Using data from the United Network for Organ Sharing 2003-2013 LT registry, we evaluated race/ethnicity-specific disparities in LT waitlist survival and probability of receiving LT among chronic HCV patients listed for LT.

RESULTS

Among 43,478 HCV patients listed for LT (70.0% non-Hispanic white, 10.8% black, 16.3% Hispanic, 2.9% Asian), HCV-related LT waitlist registrations increased by 21.5% from 2003 to 2013. During this period, the proportion of HCV patients with HCC increased by 237%, and in 2013, HCV patients with HCC accounted for 33.0% of HCV-related waitlist registrations. When stratified by race/ethnicity, Hispanics with HCV had significantly lower waitlist mortality (OR 0.83; 95% CI 0.74-0.94; p < 0.01) compared to non-Hispanic whites, but no significant differences were seen among blacks and Asians. Furthermore, compared to non-Hispanic whites, Hispanics were significantly less likely to receive LT (OR 0.58; 95% CI 0.53-0.62; p < 0.001), but no differences were seen among blacks or Asians.

CONCLUSION

Among patients with chronic HCV in the USA, the MELD score has reduced race/ethnicity-specific disparities in waitlist mortality. However, Hispanic HCV patients had significantly better waitlist survival and lower probability of receiving LT, possibly reflecting slower disease progression compared to non-Hispanic whites with chronic HCV.

The Impact of the Share 35 Policy on Racial and Ethnic Disparities in Access to Liver Transplantation for Patients with End Stage Liver Disease in the United States: An Analysis from UNOS Database

BACKGROUND

The Share 35 policy was instituted in June 2013 by the United Network for Organ Sharing (UNOS) in order to reduce death on liver transplant waiting list. The effect of this policy on racial and ethnic disparities in access to liver transplantation has not been examined.

METHODS

A total of 14,585 adult patients registered for liver transplantation between 2012 and 2015 were identified from UNOS database. Logistic and proportional hazards models were used to model the effects of race and ethnicity on access to liver transplantation. Stratification on pre- and post-Share 35 periods was performed to compare the first 18 months of Share 35 policy to an equivalent time period before.

RESULTS

Comparison of the pre- and post-Share 35 periods showed significantly decreased time on waiting list and increased numbers of minorities having access to liver transplantation. Hispanic recipients still experienced significantly longer waiting time (HR: 0.69, 95% CI: 0.53-0.88) before they received liver transplantation after Share 35 policy took effect.

CONCLUSION

The Share 35 policy did not lead to improved access to liver transplantation among minorities but eliminated the previously observed racial and ethnic disparities in transplant rates as well as shortened the waiting time.

National Outcomes of Liver Transplantation for Model for End-Stage Liver Disease Score ≥40: The Impact of Share 35

In certain regions of the United States in which organ donor shortages are persistent and competition is high, recipients wait longer and are critically ill with Model for End-Stage Liver Disease (MELD) scores ≥40 when they undergo liver transplantation. Recent implementation of Share 35 has increased the percentage of recipients transplanted at these higher MELD scores. The purpose of our study was to examine national data of liver transplant recipients with MELD scores ≥40 and to identify risk factors that affect graft and recipient survival. During the 12-year study period, 5002 adult recipients underwent deceased donor whole-liver transplantation. The 1-, 3-, 5- and 10-year graft survival rates were 77%, 69%, 64% and 50%, respectively. The 1-, 3-, 5- and 10-year patient survival rates were 80%, 72%, 67% and 53%, respectively. Multivariable analysis identified previous transplant, ventilator dependence, diabetes, hepatitis C virus, age >60 years and prolonged hospitalization prior to transplant as recipient factors increasing the risk of graft failure and death. Donor age >30 years was associated with an incrementally increased risk of graft failure and death. Recipients after implementation of Share 35 had shorter waiting times and higher graft and patient survival compared with pre-Share 35 recipients, demonstrating that some risk factors can be mitigated by policy changes that increase organ accessibility.

Survival outcomes in liver transplant recipients with Model for End-stage Liver Disease scores of 40 or higher: a decade-long experience

BACKGROUND

The Model for End-stage Liver Disease (MELD) has been used as a prognostic tool since 2002 to predict pre-transplant mortality. Increasing proportions of transplant candidates with higher MELD scores, combined with improvements in transplant outcomes, mandate the need to study surgical outcomes in patients with MELD scores of ≥40.

METHODS

A retrospective longitudinal analysis of United Network for Organ Sharing (UNOS) data on all liver transplantations performed between February 2002 and June 2011 (n = 33,398) stratified by MELD score (<30, 30-39, ≥40) was conducted. The primary outcomes of interest were short- and longterm graft and patient survival. A Kaplan-Meier product limit method and Cox regression were used. A subanalysis using a futile population was performed to determine futility predictors.

RESULTS

Of the 33,398 transplant recipients analysed, 74% scored <30, 18% scored 30-39, and 8% scored ≥40 at transplantation. Recipients with MELD scores of ≥40 were more likely to be younger (P < 0.001), non-White and to have shorter waitlist times (P < 0.001). Overall patient survival correlated inversely with increasing MELD score; this trend was consistent for both short-term (30 days and 90 days) and longterm (1, 3 and 5 years) graft and patient survival. In multivariate analysis, increasing age, African-American ethnicity, donor obesity and diabetes were negative predictors of survival. Futility predictors included patient age of >60 years, obesity, peri-transplantation intensive care unit hospitalization with ventilation, and multiple comorbidities.

CONCLUSIONS

Liver transplantation in recipients with MELD scores of ≥40 offers acceptable longterm survival outcomes. Futility predictors indicate the need for prospective follow-up studies to define the population to gain the highest benefit from this precious resource.

[Deceased donor liver transplantation]

Deceased donor liver transplantation is nowadays a routine procedure for the treatment of terminal liver failure and often represents the only chance of a cure. Under given optimal conditions excellent long-term results can be obtained with 15-year survival rates of well above 60 %.In Germany the outcome after liver transplantation has deteriorated since the introduction of an allocation policy, which is based on the medical urgency. At present 25 % of liver graft recipients die within the first year after transplantation. In contrast 1-year survival in most other countries, e.g. in the USA or the United Kingdom is around 90 % and therefore significantly better. Reasons for the inferior results in Germany are on the one hand an increasing number of critically ill recipients and on the other hand an unfavorable situation for organ donation. In comparison with other countries the organ donation rate is low and moreover the risk profile of these donors is above average. This combination of organ shortage and organ allocation represents a big challenge for the future orientation of liver transplantation and creates the potential for conflict. These cannot be solved on a medical basis but require a social consensus.Because of the present inferior results and because of the high expenses of the present system we suggest a discussion on future allocation policies as well as on future centre structures in Germany. In addition to the medical urgency the maximum benefit should also be considered for organ allocation.

Assessing variation in the costs of care among patients awaiting liver transplantation

Previous economic analyses of liver transplantation have focused on the cost of the transplant and subsequent care. Accurate characterization of the pretransplant costs, indexed to severity of illness, is needed to assess the economic burden of liver disease. A novel data set linking Medicare claims with transplant registry data for 15,710 liver transplant recipients was used to determine average monthly waitlist spending (N = 249,434 waitlist months) using multivariable linear regression models to adjust for recipient characteristics including Model for End-Stage Liver Disease (MELD) score. Characteristics associated with higher spending included older age, female gender, hepatocellular carcinoma, diabetes, hypertension and increasing MELD score (p < 0.05 for all). Spending increased exponentially with severity of illness: expected monthly spending at a MELD score of 30 was 10 times higher than at MELD of 20 ($22,685 vs. $2030). Monthly spending within MELD strata also varied geographically. For candidates with a MELD score of 35, spending varied from $19,548 (region 10) to $36,099 (region 7). Regional variation in waitlist costs may reflect the impact of longer waiting times on greater pretransplant hospitalization rates among high MELD score patients. Reducing the number of high MELD waitlist patients through improved medical management and novel organ allocation systems could decrease total spending for end-stage liver care.

The MELD system and liver transplant waiting-list mortality in developing countries: lessons learned from São Paulo, Brazil

OBJECTIVE

The MELD system has not yet been tested as an allocation tool for liver transplantation in the developing countries. In 2006, MELD (Model for End-stage Liver Disease) was launched as a new liver allocation system in São Paulo, Brazil. This study was designed to assess the results of the new allocation policy on waiting list mortality.

METHODS

The State of São Paulo liver transplant database was retrospectively reviewed from July 2003 through July 2009. Patients were divided into those who were transplanted before (Pre-MELD Group) and those who were transplanted after (post-MELD Group) the implementation of the MELD system. Only adult liver transplant candidates were included. Waiting list mortality was the primary endpoint.

RESULTS

The unadjusted death rate in waiting list decreased significantly after the implementation of the MELD system (from 91.2 to 33.5/1,000 patients per year; p<0.0001). Multivariate analysis showed a significant drop in risk of waiting list death for post-MELD patients (HR 0.34; p<0.0001). Currently, 48% of patients are transplanted within 1-year of listing (versus 23% in the pre-MELD era; p<0.0001). Patient and graft survival did not change with MELD implementation.

CONCLUSION

There was a reduction in waiting time and list mortality after implementation of the MELD system in São Paulo. Patients listed in the post-MELD era had a significant reduction in risk for the waiting list mortality. There were no changes in post-transplant outcomes. MELD can be successfully utilized for liver transplant allocation in developing countries.

Predicting early allograft failure and mortality after liver transplantation: the role of the postoperative model for end-stage liver disease score

Early allograft dysfunction (EAD) is a serious complication after liver transplantation (LT). There is no uniform definition of EAD, and most definitions are based on arbitrary laboratory values. The aim of this study was to devise a definition of EAD that maximizes the predictive power for early death and graft failure. In this single-center, retrospective study, the ability of the international normalized ratio (INR), total bilirubin, aspartate aminotransferase (AST), physiological Model for End-Stage Liver Disease (MELD) score, and serum albumin levels within 7 days after LT to predict 90-day mortality or graft loss was compared with 2 previously used definitions of EAD: (1) peak total bilirubin level >10 mg/dL on days 2 to 7 and (2) either a total bilirubin level >10 mg/dL or an INR >1.6 on day 7 or an AST or alanine aminotransferase level >2000 IU/L within the first 7 days. Of 572 enrolled LT patients 38 died or required retransplantation within 90 days. Peak INR, total bilirubin level, AST levels, and MELD scores were predictors of 90-day graft failure. MELD score on postoperative day 5 was the best predictor with an area under the curve of the receiver operating characteristic curve of 0.812 (95% CI: 0.739-0.886, P < 0.001). The best cutoff of MELD score on day 5 for predicting 90-day mortality or graft loss was 18.9. A MELD score >18.9 on postoperative day 5 was a better predictor than any other laboratory value or definition of EAD. This study has demonstrated that the MELD score can be a useful tool not only for pretransplant graft allocation but also for postoperative risk stratification.

A decade of model for end-stage liver disease: lessons learned and need for re-evaluation of allocation policies

PURPOSE OF REVIEW

The model for end-stage liver disease (MELD) driven liver allocation system has been in place for 10 years now. Understanding what the driving forces were, what principles were developed and employed, and assessing how these have stood the test of time will help future policy makers further refine the system.

RECENT FINDINGS

Prior to development of the MELD system, policymakers had limited data and organ allocation policy development was rarely systematic or evidence-based and was not necessarily centered on the patient. The MELD process focused on patient-specific variables and validation of the risk prediction models to be sure the system would function reasonably well across the spectrum of potential candidates and that it did not impose artificial categorizations of patients. In addition, the transplant community focused on assessing the effects of this policy change which was also something new.

SUMMARY

Numerous publications since have reported outcomes for MELD-based liver allocation here in the United States and in many other areas around the world. Some of these reports have suggested changes to the MELD equation or other ways to adapt the system to more accurately reflect the need for transplant. The transparency that this type of system brings allows for much more rigorous assessment of results and for highlighting areas for improvement toward a more fair, equitable, and utilitarian system.

The aggressive phenotype revisited: utilization of higher-risk liver allografts

Organ shortage has led to increased utilization of higher risk liver allografts. In kidneys, aggressive center-level use of one type of higher risk graft clustered with aggressive use of other types. In this study, we explored center-level behavior in liver utilization. We aggregated national liver transplant recipient data between 2005 and 2009 to the center-level, assigning each center an aggressiveness score based on relative utilization of higher risk livers. Aggressive centers had significantly more patients reaching high MELDs (RR 2.19, 2.33 and 2.28 for number of patients reaching MELD>20, MELD>25 and MELD>30, p<0.001), a higher organ shortage ratio (RR 1.51, 1.60 and 1.51 for number of patients reaching MELD>20, MELD>25 and MELD>30 divided by number of organs recovered at the OPO, p<0.04), and were clustered within various geographic regions, particularly regions 2, 3 and 9. Median MELD at transplant was similar between aggressive and nonaggressive centers, but average annual transplant volume was significantly higher at aggressive centers (RR 2.27, 95% CI 1.47-3.51, p<0.001). In cluster analysis, there were no obvious phenotypic patterns among centers with intermediate levels of aggressiveness. In conclusion, highwaitlist disease severity, geographic differences in organ availability, and transplant volume are the main factors associated with the aggressive utilization of higher risk livers.

Donor assessment scores: relevance and complete irrelevance

1. Donor assessment scores can be used to prognosticate recipient outcomes but are often not clinically relevant. 2. The donor risk index, the survival outcomes following liver transplantation score, and the Donor Model for End-Stage Liver Disease score have specific advantages and disadvantages with respect to accuracy and ease of use. 3. The significance of the donor assessment is undermined by an allocation system that sometimes limits ideal donor-recipient matching and whose sole objective is the minimization of wait-list mortality instead of the benefit of transplantation.

Kidney transplantation alone in ESRD patients with hepatitis C cirrhosis

BACKGROUND

Kidney transplantation (KTx) alone in patients with cirrhosis and renal failure (end-stage renal disease [ESRD]) infected with hepatitis C virus (HCV) is controversial. The aim of this study was to compare outcomes of HCV+ patients with ESRD and cirrhosis (C group) versus HCV+ patients with ESRD but with no cirrhosis (NC group) listed for KTx.

METHODS

Ninety HCV+ patients with ESRD were evaluated for KTx between 2003 and 2010. Listed patients underwent transjugular liver biopsy with hepatic portal venous gradient (HPVG) measurements. Only patients with HPVG less than 10 mm Hg were considered for KTx alone. We analyzed patient demographics, waitlist/liver disease characteristics, and posttransplant outcomes between groups.

RESULTS

Sixty-four patients listed for KTx alone were studied. Twelve patients (18.75%) showed biopsy-proven cirrhosis. Thirty-seven patients underwent KTx alone (9 from C and 28 from NC). No patients developed decompensation of their liver disease, although one patient for NC group developed metastatic hepatocellular carcinoma 16 months after transplantation. One- and three-year graft survival rates were 75% and 75% versus 92.1% and 75.1% for groups C and NC, respectively (P=0.72). One- and three-year patient survival rates were 88.9% and 88.9% versus 96.3% and 77.9% for groups C and NC, respectively (P=0.76). Only increasing recipient age and decreasing albumin levels were significantly associated with worse graft and patient survival.

CONCLUSIONS

Our study suggests that KTx alone may be safe in patients with compensated HCV, cirrhosis, and ESRD with HPVG less than 10 mm Hg. A simultaneous liver-kidney transplantation may be an unnecessary use of a liver allograft in these patients.

Pretransplant prediction of posttransplant survival for liver recipients with benign end-stage liver diseases: a nonlinear model

Background

The scarcity of grafts available necessitates a system that considers expected posttransplant survival, in addition to pretransplant mortality as estimated by the MELD. So far, however, conventional linear techniques have failed to achieve sufficient accuracy in posttransplant outcome prediction. In this study, we aim to develop a pretransplant predictive model for liver recipients' survival with benign end-stage liver diseases (BESLD) by a nonlinear method based on pretransplant characteristics, and compare its performance with a BESLD-specific prognostic model (MELD) and a general-illness severity model (the sequential organ failure assessment score, or SOFA score).

Methodology/Principal Findings

With retrospectively collected data on 360 recipients receiving deceased-donor transplantation for BESLD between February 1999 and August 2009 in the west China hospital of Sichuan university, we developed a multi-layer perceptron (MLP) network to predict one-year and two-year survival probability after transplantation. The performances of the MLP, SOFA, and MELD were assessed by measuring both calibration ability and discriminative power, with Hosmer-Lemeshow test and receiver operating characteristic analysis, respectively. By the forward stepwise selection, donor age and BMI; serum concentration of HB, Crea, ALB, TB, ALT, INR, Na⁺; presence of pretransplant diabetes; dialysis prior to transplantation, and microbiologically proven sepsis were identified to be the optimal input features. The MLP, employing 18 input neurons and 12 hidden neurons, yielded high predictive accuracy, with c-statistic of 0.91 (P<0.001) in one-year and 0.88 (P<0.001) in two-year prediction. The performances of SOFA and MELD were fairly poor in prognostic assessment, with c-statistics of 0.70 and 0.66, respectively, in one-year prediction, and 0.67 and 0.65 in two-year prediction.

Conclusions/Significance

The posttransplant prognosis is a multidimensional nonlinear problem, and the MLP can achieve significantly high accuracy than SOFA and MELD scores in posttransplant survival prediction. The pattern recognition methodologies like MLP hold promise for solving posttransplant outcome prediction.

Presentation and outcomes of hepatocellular carcinoma patients at a western centre

BACKGROUND

The present study examines the presentation and outcomes of hepatocellular carcinoma (HCC) at a Western centre over the last decade.

METHODS

Between January 2000 and September 2009, 1010 patients with HCC were evaluated at the University of Pittsburgh Medical Center (UPMC). Retrospectively, four treatment groups were classified: no treatment (NT), systemic therapy (ST), hepatic artery-based therapy (HAT) and surgical intervention (SI) including radiofrequency ablation, hepatic resection and transplantation. Kaplan-Meier analysis assessed survival between groups. Cox regression analysis identified factors predicting survival.

RESULTS

Patients evaluated were 75% male, 87% Caucasian, 84% cirrhotic, and predominantly diagnosed with hepatitis C. In all, 169 patients (16.5%) received NT, 25 (2.4%) received ST, 529 (51.6%) received HAT and 302 (29.5%) received SI. Median survival was 3.6, 5.6, 8.8, and 83.5 months with NT, ST, HAT and SI, respectively (P= 0.001). Transplantation increased from 9.5% to 14.2% after the model for end-stage liver disease (MELD) criteria granted HCC patients priority points. Survival was unaffected by bridging transplantation with HAT or SI (P= 0.111). On multivariate analysis, treatment modality was a robust predictor of survival after adjusting for age, gender, AFP, Child-Pugh classification and cirrhosis (P < 0.001, χ(2) = 460).

DISCUSSION

  Most patients were not surgical candidates and received HAT alone. Surgical intervention, especially transplantation, yields the best survival.

Risk factors for long-term mortality in a large cohort of patients wait-listed for liver transplantation in Brazil

Liver donor shortage and long waiting times are observed in many liver transplant programs worldwide. The aim of this study was to evaluate the wait list in a developing country, before and after the introduction of the MELD scoring system. In addition, the MELD score ability to predict mortality in this setting was assessed. A single-center retrospective study of patients wait-listed for liver transplantation between 1997 and 2010 was undertaken. There were 1339 and 762 patients on the list in pre-MELD and MELD era, respectively. A competitive risk analysis was performed to assess age, gender, disease diagnosis, serum sodium, MELD, Child-Pugh, ABO type, and body mass index. Also, MELD score predictive ability at 3, 6, 12, and 24 months after list enrollment was evaluated. The overall mortality rates on waiting list were 31.0% and 28.1% (P = 0.16), and the median waiting times were 412 and 952 days (P < 0.001), in pre and MELD eras, respectively. The competitive risk analysis yielded the following significant P values for both eras: HCC (0.03 and <0.001), MELD (<0.001 and 0.002), sodium level (0.002 and <0.001), and Child-Pugh (0.02 and <0.001). The MELD mortality predictions at 3, 6, 12, and 24 months were similar. In conclusion, in a liver transplant program with long waiting times, the MELD system introduction did not improve mortality rate. In either pre and MELD eras, HCC diagnosis, serum sodium, Child-Pugh, and MELD were significant predictors of prognosis. Short- and long-term MELD based mortality predictions were similarly accurate. Strategies for increasing the liver donor pool should be implemented to improve mortality.

The economic implications of broader sharing of liver allografts

Liver transplantation has evolved over the past four decades into the most effective method to treat end-stage liver failure and one of the most expensive medical technologies available. Accurate understanding of the financial implication of recipient severity of illness is crucial to assessing the economic impact of allocation policies. A novel database of linked clinical data from the Organ Procurement and Transplantation Network with cost accounting data from the University HealthSystem Consortium was used to analyze liver transplant costs for 15,813 liver transplants. This data was then utilized to consider the economic impact of alternative allocation systems designed to increase sharing of liver allografts using simulation results. Transplant costs were strongly associated with recipient severity of illness as assessed by the MELD score (p < 0.0001); however, this relationship was not linear. Simulation analysis of the reallocation of livers from low MELD patients to high MELD using a two-tiered regional sharing approach (MELD 15/25) resulted in 88 fewer deaths annually at estimated cost of $17,056 per quality-adjusted life-year saved. The results suggest that broader sharing of liver allografts offers a cost-effective strategy to reduce the mortality from end stage liver disease.

High mortality in orthotopic liver transplant recipients who require hemodialysis

Acute renal failure is a significant risk factor for death in patients with liver failure. The goal of this study was to analyze the impact of peri-transplant dialysis on the long-term mortality of liver transplant recipients. We performed a single-center, retrospective cohort study of 743 adult liver transplants; patients who received first liver transplants were divided into four groups: those who received more than one dialysis treatment (hemodialysis [HD], continuous veno-venous hemodialysis [CVVH]) pre-orthotopic liver transplantation (OLT), post OLT, pre- and post OLT, and those not dialyzed. There was no statistically significant difference in the mean survival time for patients who were not dialyzed or dialyzed only pre-OLT. Mean survival times were markedly reduced in patients dialyzed post OLT or both pre- and post OLT compared with those never dialyzed. Mortality risk in a Cox proportional hazards model correlated with hemodialysis post OLT, intra-operative vasopressin or neosynephrine, donor age >50 yr, Cr >1.5 mg/dL at transplant, and need for subsequent retransplant. Risk of post-OLT dialysis was correlated with pre-OLT dialysis, intra-operative levophed, pre-OLT diabetes, African American race, pre-OLT Cr >1.5, and male gender. We conclude that renal failure requiring hemodialysis post liver transplant, irrespective of pre-transplant dialysis status, is a profound risk factor for death in liver transplant recipients.

Geographic inequity in access to livers for transplantation

BACKGROUND

Liver transplantation offers life-saving therapy for patients with decompensated liver disease or T2 hepatocellular carcinomas. In the United States, deceased donor livers are primarily allocated by Model for End-Stage Liver Disease (MELD) score within each of the country's more than 50 donation service areas (DSAs). Variation in DSA size, population, and organ availability have engendered concern that unequal access to deceased donor livers across DSAs contributes to geographic variability in outcome.

METHODS

To determine the extent to which DSA variability in organ availability correlated with combined waitlist and posttransplant mortality, we analyzed retrospectively national waitlist and posttransplant data for a 7-year period after implementation of the current MELD-based allocation system.

RESULTS

Marked variation among DSAs was evident in death rate (3.3-fold), transplant rate (20-fold), and mean transplant MELD (>10 points). Death rate correlated with organ availability was assessed by transplant rate and transplant MELD. DSAs with low organ availability included the country's largest cities, had more new listings per capita, larger waitlists, more transplant centers per DSA, and a higher proportion of black and Asian patients. DSAs of organ shortage were also characterized by more frequent dual listing at another transplant center, more living donor liver transplants, and increased average length of the transplant admission.

CONCLUSIONS

Geographic differences in deceased donor organ availability contribute to variation in overall death rate of liver transplant patients, shape the clinical practice of transplant, and influence the resources consumed per transplant. Geographic variation in organ access results primarily from rates of listing rather than donation. Our findings highlight the need to restructure organ distribution areas to achieve equal access to deceased donor livers for transplantation in the United States.

Do chronic liver disease scoring systems predict outcomes in trauma patients with liver disease? A comparison of MELD and CTP

BACKGROUND

Although the Child-Turcotte-Pugh (CTP) score is an established outcome prediction tool for patients with liver disease, the Model for End-Stage Liver Disease (MELD) score has recently supplanted CTP for patients awaiting transplantation. Currently, data regarding the use of CTP in trauma is limited, whereas MELD remains unstudied. We compared MELD and CTP to determine which scoring system is a better clinical outcome predictor after trauma.

METHODS

A review of trauma admissions during 2003-2008 revealed 68 patients with chronic liver disease. Single and multiple variable analyses determined predictors of hepatic complications and survival. MELD and CTP were compared using odds ratios and area under the receiver operating curve (AUC) analyses. A p value ≤0.05 was significant.

RESULTS

The mean MELD and CTP scores of the population were 13.1 ± 6.0 and 8.3 ± 1.8, respectively (mean ± SD). Overall, 73.5% had one or more complications and 29.4% died. When survivors were compared with nonsurvivors, no difference in mean MELD scores was found, although mean CTP score (survivors, 7.7 ± 1.5; nonsurvivors, 9.4 ± 1.9; p = 0.001) and class ("C" survivors, 12.1%; "C" nonsurvivors, 56.3%; p = 0.002) were different, with survival relating to liver disease severity. Odds ratios and AUC determined that MELD was not predictive of hepatic complications or hospital survival (p > 0.05), although both CTP score and class were predictive (p < 0.05; AUC > 0.70).

CONCLUSION

Trauma patients suffering from cirrhosis can be expected to have poorer than predicted outcomes using traditional trauma scoring systems, regardless of injury severity. Scoring systems for chronic liver disease offer a more effective alternative. We compared two scoring systems, MELD and CTP, and determined that CTP was the better predictor of hepatic complications and survival in our study population.

Racial and ethnic disparities in access to liver transplantation

Access to liver transplantation is reportedly inequitable for racial/ethnic minorities, but inadequate adjustments for geography and disease progression preclude any meaningful conclusions. We aimed to evaluate the association between candidate race/ethnicity and liver transplant rates after thorough adjustments for these factors and to determine how uniform racial/ethnic disparities were across Model for End-Stage Liver Disease (MELD) scores. Chronic end-stage liver disease candidates initially wait-listed between February 28, 2002 and February 27, 2007 were identified from Scientific Registry for Transplant Recipients data. The primary outcome was deceased donor liver transplantation (DDLT); the primary exposure covariate was race/ethnicity (white, African American, Hispanic, Asian, and other). Cox regression was used to estimate the covariate-adjusted DDLT rates by race/ethnicity, which were stratified by the donation service area and MELD score. With averaging across all MELD scores, African Americans, Asians, and others had similar adjusted DDLT rates in comparison with whites. However, Hispanics had an 8% lower DDLT rate versus whites [hazard ratio (HR) = 0.92, P = 0.011]. The disparity among Hispanics was concentrated among patients with MELD scores < 20, with HR = 0.84 (P = 0.021) for MELD scores of 6 to 14 and HR = 0.85 (P = 0.009) for MELD scores of 15 to 19. Asians with MELD scores < 15 had a 24% higher DDLT rate with respect to whites (HR = 1.24, P = 0.024). However, Asians with MELD scores of 30 to 40 had a 46% lower DDLT rate (HR = 0.54, P = 0.004). In conclusion, although African Americans did not have significantly different DDLT rates in comparison with similar white candidates, race/ethnicity-based disparities were prominent among subgroups of Hispanic and Asian candidates. By precluding the survival benefit of liver transplantation, this inequity may lead to excess mortality for minority candidates.

Survival benefit of liver transplantation and the effect of underlying liver disease

BACKGROUND

The benefit of liver transplantation relative to initial degree of underlying liver disease and time on the waiting list remains poorly defined. We sought to examine the survival benefit attributable to liver transplantation across a wide range of Model for End-Stage Liver Disease (MELD) scores.

METHODS

The study population included patients with end-stage liver disease enlisted in Rio Grande do Sul, Brazil, between 2001 and 2005. Survival and hazard function for enlisted and transplanted patients were estimated using parametric and nonparametric methods. MELD score was utilized to account for underlying liver disease.

RESULTS

Of 1,130 eligible patients, 520 (46.0%) were transplanted, 266 (23.5%) died on the waiting list, 141 (12.5%) were excluded from the waiting list, and 203 (18.0%) remained enlisted and were awaiting transplantation at the time of last observation. At 1 year after transplantation, a MELD score of 15 represented a transition point in terms of overall survival benefit (MELD 10, 90% vs 83%; MELD 15, 81% vs 80%; MELD 20, 63% vs 78%; MELD 25, 42% vs 74%; MELD 30, 21% vs71%; enlisted vs transplant patients, respectively). MELD scores at which transplantation seemed to be beneficial relative to the amount of follow-up time was MELD 23, 17, 15, and 12 at 6 months, and 1, 2, and 5 years, respectively, from time of transplantation/enlistment.

CONCLUSION

Although patients with greater MELD scores enjoy a pronounced and early benefit from transplantation, patients with lesser MELD scores do gain from transplantation, although a greater period of time is needed to realize the survival benefit.