MELD: the answer or just more questions?

Inconsistent values and algorithmic fairness: a review of organ allocation priority systems in the United States

BACKGROUND

The Organ Procurement and Transplant Network (OPTN) Final Rule guides national organ transplantation policies, mandating equitable organ allocation and organ-specific priority stratification systems. Current allocation scores rely on mortality predictions.

METHODS

We examined the alignment between the ethical priorities across organ prioritization systems and the statistical design of the risk models in question. We searched PubMed for literature on organ allocation history, policy, and ethics in the United States.

RESULTS

We identified 127 relevant articles, covering kidney (19), liver (60), lung (24), and heart transplants (23), and transplant accessibility (1). Current risk scores emphasize model performance and overlook ethical concerns in variable selection. The inclusion of race, sex, and geographical limits as categorical variables lacks biological basis; therefore, blurring the line between evidence-based models and discrimination. Comprehensive ethical and equity evaluation of risk scores is lacking, with only limited discussion of the algorithmic fairness of the Model for End-Stage Liver Disease (MELD) and the Kidney Donor Risk Index (KDRI) in some literature. We uncovered the inconsistent ethical standards underlying organ allocation scores in the United States. Specifically, we highlighted the exception points in MELD, the inclusion of race in KDRI, the geographical limit in the Lung Allocation Score, and the inadequacy of risk stratification in the Heart Tier system, creating obstacles for medically underserved populations.

CONCLUSIONS

We encourage efforts to address statistical and ethical concerns in organ allocation models and urge standardization and transparency in policy development to ensure fairness, equitability, and evidence-based risk predictions.

A machine learning approach to model for end-stage liver disease score in cardiac surgery

OBJECTIVE

Model for end-stage liver disease (MELD) likely has nonlinear effects on operative outcomes. We use machine learning to evaluate the nonlinear (dependent variable may not correlate one to one with an increased risk in the outcome) relationship between MELD and outcomes of cardiac surgery.

METHODS

Society of Thoracic Surgery indexed elective cardiac operations between 2011 and 2018 were included. MELD was retrospectively calculated. Logistic regression models and an imbalanced random forest classifier were created on operative mortality. Cox regression models and random forest survival models evaluated survival. Variable importance analysis (VIMP) ranked variables by predictive power. Linear and machine-learned models were compared with receiver operator characteristic (ROC) and Brier score.

RESULTS

We included 3872 patients. Operative mortality was 1.7% and 5-year survival was 82.1%. MELD was the fourth largest positive predictor on VIMP analysis for operative long-term survival and the strongest negative predictor for operative mortality. MELD was not a significant predictor for operative mortality or long-term survival in the logistic or Cox regressions. The logistic model ROC area was 0.762, compared to the random forest classifier ROC of 0.674. The Brier score of the random forest survival model was larger than the Cox regression starting at 2 years and continuing throughout the study period. Bootstrap estimation on linear regression demonstrated machine-learned models were superior.

CONCLUSIONS

MELD and mortality are nonlinear. MELD was insignificant in the Cox multivariable regression but was strongly important in the random forest survival model and when using bootstrapping, the superior utility was demonstrated of the machine-learned models.

Serum cystatin C as a predictor of 90-day mortality among patients admitted with complications of cirrhosis

BACKGROUND AND AIM

Cystatin C (Cys) is not affected by age, sex, and muscle mass. We evaluated to compare the predictive performance of serum Cys level and model for end-stage liver disease (MELD) score and developed a new model to predict 90-day mortality among patients admitted with cirrhosis complications.

METHODS

A prospective cohort study was performed from December 2018 to December 2019. All cirrhotic patients admitted with acute decompensated liver cirrhosis or acute on chronic liver failure had laboratory values measured within 48 h of admission.

RESULTS

A cohort of 225 patients with cirrhosis was admitted during the study period. Sixty-five patients were eligible for analysis. Twenty-seven of these patients (41.4%) died within 90 days of follow-up. The median of MELD score was 20.5 (15, 24). Serum Cys level of >1.45 mg/L had the highest 90-day mortality prediction with the sensitivity and specificity of 66.7% and 68.4%, respectively. Cys and MELD scores were predictive of 90-day mortality: Cys hazard ratio (HR) = 2.04 (95% CI 1.01-4.14, P = 0.048); MELD score HR = 1.01 (95% CI 0.51-2.01, P = 0.970). C-statistic of Cys, MELD score, model for end-stage liver disease-cystatin C (MELD-Cys) score, combined Cys with MELD-Cys score to predict 90-day mortality were 0.67, 0.58, 0.58, and 0.63, respectively. Adding Cys to the MELD score did not improve the predictive of 90-day mortality.

CONCLUSION

Serum Cys is superior to MELD score, and the new MELD-Cys model is comparable to the MELD score in predicting mortality among patients with cirrhosis admitted with complications.

The Effect of Donor Age and Recipient Characteristics on Renal Outcomes in Patients Receiving Prolonged-Release Tacrolimus After Liver Transplantation: Post-Hoc Analyses of the DIAMOND Study

Background

The DIAMOND study of de novo liver transplant patients showed that prolonged-release tacrolimus exposure in the acute post-transplant period maintained renal function over 24 weeks of treatment. To assess these findings further, we performed a post-hoc analysis in patients according to baseline kidney function, Model for End-stage Liver Disease [MELD] scores, and donor age.

Material/Methods

Patients received prolonged-release tacrolimus (initial-dose, Arm 1: 0.2 mg/kg/day, Arm 2: 0.15–0.175 mg/kg/day, Arm 3: 0.2 mg/kg/day delayed until Day 5), mycophenolate mofetil and 1 steroid bolus. Arms 2 and 3 also received basiliximab. The recommended tacrolimus target trough levels to Day 42 post-transplantation were 5–15 ng/mL in all arms. In this post-hoc analysis, change in renal outcome, based on estimated glomerular filtration rate (eGFR), Modified Diet in Renal Disease-4 (MDRD4), values from baseline to Week 24 post-transplantation, were assessed according to baseline patient factors: eGFR (≥60 and <60 mL/min/1.73 m²), MELD score (<25 and ≥25) and donor age (<50 and ≥50 years).

Results

Baseline characteristics were comparable (Arms 1–3: n=283, n=287, n=274, respectively). Patients with baseline renal function, eGFR ≥60 mL/min/1.73 m², experienced a decrease in eGFR in all tacrolimus treatment arms. In patients with lower baseline renal function (eGFR <60 mL/min/1.73 m²), an advantage for renal function was observed with both the early lower-dose and delayed higher-dose tacrolimus regimens compared with the early introduction of higher-dose tacrolimus. At Week 24, renal function was higher in the early-lower tacrolimus arm with older donors, and the delayed higher-dose tacrolimus arm with younger donors, both compared with early higher-dose tacrolimus.

Conclusions

Pre-transplantation factors, such as renal function and donor age, could guide the choice of prolonged-release tacrolimus regimen following liver transplantation.

Prospective Assessment of Liver Function by an Enzymatic Liver Function Test to Estimate Short-Term Survival in Patients with Liver Cirrhosis

BACKGROUND

MELD attempts to objectively predict the risk of mortality of patients with liver cirrhosis and is commonly used to prioritize organ allocation. Despite the usefulness of the MELD, updated metrics could further improve the accuracy of estimates of survival.

AIMS

To assess and compare the prognostic ability of an enzymatic ¹³C-based liver function test (LiMAx) and distinct markers of liver function to predict 3-month mortality of patients with chronic liver failure.

METHODS

We prospectively investigated liver function of 268 chronic liver failure patients without hepatocellular carcinoma. Primary study endpoint was liver-related death within 3 months of follow-up. Prognostic values were calculated using Cox proportional hazards and logistic regression analysis.

RESULTS

The Cox proportional hazard model indicated that LiMAx (p < 0.001) and serum creatinine values (p < 0.001) were the significant parameters independently associated with the risk of liver failure-related death. Logistic regression analysis revealed LiMAx and serum creatinine to be independent predictors of mortality. Areas under the receiver-operating characteristic curves for MELD (0.86 [0.80-0.92]) and for a combined score of LiMAx and serum creatinine (0.83 [0.76-0.90]) were comparable.

CONCLUSIONS

Apart from serum creatinine levels, enzymatic liver function measured by LiMAx was found to be an independent predictor of short-term mortality risk in patients with liver cirrhosis. A risk score combining both determinants allows reliable prediction of short-term prognosis considering actual organ function. Trial Registration Number (German Clinical Trials Register) # DRKS00000614.

Scoring systems for prediction of mortality in decompensated liver cirrhosis: A meta-analysis of test accuracy

AIM

To compare the accuracy of the scoring systems Child-Turcotte-Pugh (CTP), Model for End-stage Liver Disease score (MELD), MELD-Na, and MELD to Serum Sodium ratio (MESO) to predict the mortality in decompensated liver cirrhosis.

METHODS

The PubMed, Web of Science, Cochrane Library, EMBASE, and Ovid databases were systematically searched from inception to September 2018 for relevant articles, and we evaluated the quality of the included studies. The accuracy of scoring systems was analyzed with Stata 12 and MetaDiSc 1.4.

RESULTS

Sixteen studies involving 2337 patients were included. The pooled areas under the summary receiver operating characteristic curves (AUROCs) of CTP, MELD, MELD-Na, and MESO to predict mortality were 0.81, 0.78, 0.85, and 0.86, respectively. Within 3 mo, the AUROCs of CTP, MELD, and MELD-Na in predicting mortality were 0.78, 0.76, and 0.89, respectively. The AUROCs of CTP, MELD, and MELD-Na at 3 mo were 0.86, 0.78, and 0.86, respectively. The AUROCs of CTP, MELD, and MELD-Na at 6 mo were 0.91, 0.83, and 0.90, respectively. The AUROCs of CTP, MELD, and MELD-Na at 12 mo were 0.72, 0.75 and 0.84, respectively. In cirrhotic patients with bleeding, the AUROCs of CTP and MELD were 0.76 and 0.88, respectively.

CONCLUSION

MESO has the highest AUROC in all assessed scoring systems. Considering the different time points, MELD-Na has good accuracy in predicting the mortality of decompensated liver cirrhosis. Compared to CTP, MELD is better in predicting variceal bleeding.

Occurrence of hepatopulmonary syndrome in patients with cirrhosis who are candidates for liver transplantation

OBJECTIVE

To determine the occurrence of hepatopulmonary syndrome (HPS) in patients with cirrhosis who are candidates for liver transplantation; to compare demographic, clinical, laboratory, and spirometric characteristics, as well as echocardiography results, arterial blood gas analysis, and severity of liver disease between the groups of patients with and without HPS; and to describe the occurrence of HPS in the subgroup of patients with cirrhosis and schistosomiasis mansoni (mixed liver disease).

METHODS

Between January and November of 2007, we evaluated 44 patients under treatment at the Liver Transplant Outpatient Clinic of the Federal University of Pernambuco Hospital das Clínicas, in the city of Recife, Brazil. The diagnostic criteria for HPS were intrapulmonary vascular dilatation, identified by transthoracic echocardiography, and an alveolar-arterial oxygen tension difference >or= 15 mmHg or a PaO2 < 80 mmHg.

RESULTS

The mean age of the patients was 52 years, and 31 patients (70%) were male. The most common cause of cirrhosis was alcohol use. Schistosomiasis was present in 28 patients (64%). Of the 44 patients, 20 (45.5%) were diagnosed with HPS. No significant differences were found between those patients and the patients without HPS in terms of any of the characteristics studied. Of the 28 patients with cirrhosis and schistosomiasis, 10 (35.7%) were diagnosed with HPS.

CONCLUSIONS

In the population studied, HPS was highly prevalent and did not correlate with any of the variables analyzed.

Value of model for end-stage liver disease in assessment of the prognosis of patients with cirrhosis

AIM: To compare the prognostic value of model for end-stage liver disease (MELD) and Child-Turcotte-Pugh (CTP) grading in patients with cirrhosis.

METHODS: A total of 1 790 patients with cirrhosis treated at our hospital were analyzed. These patients were allocated into two groups: survival group and death group. The MELD score and CTP classification were determined for each patient. The accuracy of MELD scoring and CTP grading in predicting the prognosis of patients with cirrhosis was assessed by comparing the area under the receiver operating characteristic curve (ROC). The predictive power of MELD scoring and CTP classification was evaluated using the cut-off approach.

RESULTS: MELD and CPT scores were significantly higher in the death group than in the survival group (both P < 0.001). The mortality of patients with cirrhosis increased with the increase in their MELD and CTP scores. The area under the ROC (AUC) of MELD was significantly higher than that of CPT (0.881 vs 0.824, P < 0.01). Survival analysis showed that both MELD scoring and CTP grading could clearly discriminate patients who survived or died (both P < 0.001). MELD values showed significant correlation with CTP scores (r = 0.705, P < 0.001).

CONCLUSION: Both MELD scoring and CTP grading can accurately predict the prognosis of patients with cirrhosis. MELD scoring is more efficient than CTP grading in predicting the prognosis of patients with cirrhosis.

Application of a biochemical and clinical model to predict individual survival in patients with end-stage liver disease

AIM: To investigate the capability of a biochemical and clinical model, BioCliM, in predicting the survival of cirrhotic patients.

METHODS: We prospectively evaluated the survival of 172 cirrhotic patients. The model was constructed using clinical (ascites, encephalopathy and variceal bleeding) and biochemical (serum creatinine and serum total bilirubin) variables that were selected from a Cox proportional hazards model. It was applied to estimate 12-, 52- and 104-wk survival. The model’s calibration using the Hosmer-Lemeshow statistic was computed at 104 wk in a validation dataset. Finally, the model’s validity was tested among an independent set of 85 patients who were stratified into 2 risk groups (low risk ≤ 8 and high risk > 8).

RESULTS: In the validation cohort, all measures of fit, discrimination and calibration were improved when the biochemical and clinical model was used. The proposed model had better predictive values (c-statistic: 0.90, 0.91, 0.91) than the Model for End-stage Liver Disease (MELD) and Child-Pugh (CP) scores for 12-, 52- and 104-wk mortality, respectively. In addition, the Hosmer-Lemeshow (H-L) statistic revealed that the biochemical and clinical model (H-L, 4.69) is better calibrated than MELD (H-L, 17.06) and CP (H-L, 14.23). There were no significant differences between the observed and expected survival curves in the stratified risk groups (low risk, P = 0.61; high risk, P = 0.77).

CONCLUSION: Our data suggest that the proposed model is able to accurately predict survival in cirrhotic patients.

Hot topics in liver transplantation: organ allocation--extended criteria donor--living donor liver transplantation

Liver transplantation has become the mainstay for the treatment of end-stage liver disease, hepatocellular cancer and some metabolic disorders. Its main drawback, though, is the disparity between the number of donors and the patients needing a liver graft. In this review we will discuss the recent changes regarding organ allocation, extended donor criteria, living donor liver transplantation and potential room for improvement. The gap between the number of donors and patients needing a liver graft forced the transplant community to introduce an objective model such as the modified model for end-stage liver disease (MELD) in order to obtain a transparent and fair organ allocation system. The use of extended criteria donor livers such as organs from older donors or steatotic grafts is one possibility to reduce the gap between patients on the waiting list and available donors. Finally, living donor liver transplantation has become a standard procedure in specialized centers as another possibility to reduce the donor shortage. Recent data clearly indicate that center experience is of major importance in achieving good results. Great progress has been made in recent years. However, further research is needed to improve results in the future.

Malnutrition in end stage liver disease: recommendations and nutritional support

Malnutrition has increasingly been acknowledged as an important prognostic factor which can influence the clinical outcome of patients suffering from end-stage liver disease (ESLD). Despite the fact that malnutrition is not included in the Child-Pugh classification, its presence should alert clinicians to the same extent as do other complications, such as ascites and hepatic encephalopathy. The pathophysiological mechanisms and the clinical conditions that drive cirrhotic patients to an ill-balanced metabolic state are multiple and they intertwine. Inadequate offer of nutrients, the hypermetabolic state in cirrhosis, the diminished synthetic capacity of the liver and the impaired absorption of nutrients are the main reasons that disrupt the metabolic balance in ESLD. Identifying patients that are approaching the state of malnutrition by simple and easily applied methods is necessary in order to provide nutritional support to those that need it most. According to the European Society for Clinical Nutrition and Metabolism, simple bedside methods such as Subjective Global Assessment and anthropometric parameters are reliable in assessing the nutritional state of cirrhotic patients. Correcting the nutrient deficit of the affected patients is mandatory. Avoidance of alcohol and excess fat and ingestion of 4-6 meals/day containing carbohydrates and protein are the most common recommendations. In severe malnutrition, initiation of enteral feeding and/or use of special formulae such as branched-chain amino acid-enriched nutrient mixtures are often recommended. Enteral nutrition improves nutritional status and liver function, reduces complications, prolongs survival and is therefore indicated.

Outcome of patients with hepatocellular carcinoma listed for liver transplantation within the Eurotransplant allocation system

Although hepatocellular carcinoma (HCC) has become a recognized indication for liver transplantation, the rules governing priority and access to the waiting list are not well defined. Patient- and tumor-related variables were evaluated in 226 patients listed primarily for HCC in Belgium, a region where the allocation system is patient-driven, priority being given to sicker patients, based on the Child-Turcotte-Pugh (CTP) score. Intention-to-treat and posttransplantation survival rates at 4 years were 56.5 and 66%, respectively, and overall HCC recurrence rate was 10%. The most significant predictors of failure to receive a transplant in due time were baseline CTP score equal to or above 9 (relative risk [RR] 4.1; confidence interval [CI]: 1.7-9.9) and alpha fetoprotein above 100 ng/mL (RR 3.0; CI: 1.2-7.1). Independent predictors of posttransplantation mortality were age equal to or above 50 years (RR 2.5; CI: 1.0-3.7) and United Network for Organ Sharing pathological tumor nodule metastasis above the Milan criteria (RR 2.1; CI: 1.0-5.9). Predictors of recurrence (10%) were alpha fetoprotein above 100 ng/mL (RR 3.2; CI:1.1-10) and vascular involvement of the tumor on the explant (RR 3.6; CI: 1.1-11.3). Assessing the value of the pretransplantation staging by imaging compared to explant pathology revealed 34% accuracy, absence of carcinoma in 8.3%, overstaging in 36.2%, and understaging in 10.4%. Allocation rules for HCC should consider not only tumor characteristics but also the degree of liver impairment. Patients older than 50 years with a stage above the Milan criteria at transplantation have a poorer prognosis after transplantation.

Model for End-Stage Liver Disease Score-Based Allocation of Donors for Liver Transplantation: A Spanish Multicenter Experience

BACKGROUND

Prioritizing the liver transplant waiting list (WL) is subject to great variability. We present the experience of four transplant centers in Andalusia (Southern Spain) with a new consensus model of WL management based on the Model for End-Stage Liver Disease (MELD) score.

METHODS

The initial criteria for local prioritizing were: a) cirrhosis with MELD score > or =24, and b) all hepatocellular carcinoma (HCC) admitted to the WL. Fourteen months later new criteria were established: a) cirrhosis with MELD score > or =18, and b) uninodular HCC between 3-5 cm or multinodular HCC (2-3 nodules <3 cm). Access to regional priority was scheduled after three months for patients with cirrhosis or six months for patients with HCC. We analyzed the WL mortality rate, posttransplant survival rate, and overall survival rate over three 14-month periods: A (before implementation of priority criteria), B (initial criteria), and C (current criteria).

RESULTS

Priority was given to 36% of recipients in period B and 47% in period C. The WL mortality rate (including removals from WL) was 12.9%, 12.9%, and 10.7% in periods A, B, and C, respectively. One-year graft survival was 79.7%, 72.6%, and 81.2% in the same periods. The overall one-year survival rate for new cases on the WL was 74.9% in period A, 68.6% in period B, and 82.2% in period C.

CONCLUSIONS

The allocation system and WL management with the current criteria resulted in lower waiting list mortality without reducing posttransplant survival, leading to better survival for all patients listed.

Nutritional status and prognosis in cirrhotic patients

BACKGROUND AND AIM

The potential prognostic value for survival of nutritional status in cirrhotics after adjusting Child-Pugh classification and Model for End-Stage Liver Disease has not been evaluated.

METHODS

We used Kaplan-Meier and Cox proportional hazards regression models to identify factors associated with mortality in a cohort of 222 cirrhotics [M/F:145/77 median age 52 (18-68) years] with prospectively collected nutritional parameters as well as modified subjective global nutritional assessment, Royal Free Hospital-Subjective Global Assessment index. Follow-up was censored at the time of transplantation. Other variables were ones in Child-Pugh and Model for End-Stage Liver Disease scores, age, aetiology of cirrhosis and renal function.

RESULTS

Pretransplant mortality (Kaplan-Meier) was 21% by 2 years (135 patients were transplanted). Among the nutritional parameters, only Royal Free Hospital-Subjective Global Assessment remained significantly associated with mortality in multivariable models (P = 0.0006). The final model included the following variables: urea (P = 0.0001), Royal Free Hospital-Subjective Global Assessment (P = 0.003), age (P = 0.0001), Child-Pugh grade (P = 0.009) and prothrombin time (P = 0.003). The results were similar when the Child-Pugh grade was replaced by the Model for End-Stage Liver Disease score in the model, and whether a competing risks model was used.

CONCLUSIONS

Nutritional indices add significantly to both Child-Pugh grade and Model for End-Stage Liver Disease scores when assessing the patient prognosis.

MELD score and clinical type predict prognosis in hepatorenal syndrome: relevance to liver transplantation

Important progress has been made recently regarding the pathogenesis and treatment of hepatorenal syndrome (HRS). However, scant information exists about factors predicting outcome in patients with cirrhosis and HRS. Moreover, the prognostic value of the model of end-stage liver disease (MELD) score has not been validated in the setting of HRS. The current study was designed to assess the prognostic factors and outcome of patients with cirrhosis and HRS. The study included 105 consecutive patients with HRS. Forty-one patients had type 1 HRS, while 64 patients had type 2 HRS. Patients with type 1 HRS not only had more severe liver and renal failure than type 2 patients, they also had greater impairment of circulatory function, as indicated by lower arterial pressure and higher activation of vasoconstrictor factors. In the whole series, the median survival was 3.3 months. In a multivariate analysis of survival, only HRS type and MELD score were associated with an independent prognostic value. All patients with type 1 HRS had a high MELD score (> or =20) and showed an extremely poor outcome (median survival: 1 mo). By contrast, the survival of patients with type 2 HRS was longer and dependent on MELD score (> or =20, median survival 3 mo; <20, median survival 11 mo; P < .002). In conclusion, the outcome of patients with cirrhosis and HRS can be estimated by using two easily available variables, HRS type and MELD score. These data can be useful in the management of patients with HRS, particularly for patients who are candidates for liver transplantation.

MELD vs Child-Pugh and creatinine-modified Child-Pugh score for predicting survival in patients with decompensated cirrhosis

AIM: Model of End-stage Liver Disease (MELD) score has recently gained wide acceptance over the old Child-Pugh score in predicting survival in patients with decompensated cirrhosis, although it is more sophisticated. We compared the predictive values of MELD, Child-Pugh and creatinine-modified Child-Pugh scores in decompensated cirrhosis.

METHODS: A cohort of 102 patients with decompensated cirrhosis followed-up for a median of 6 mo was studied. Two types of modified Child-Pugh scores estimated by adding 0-4 points to the original score using creatinine levels as a sixth categorical variable were evaluated.

RESULTS: The areas under the receiver operating charac-teristic curves did not differ significantly among the four scores, but none had excellent diagnostic accuracy (areas: 0.71-0.79). Child-Pugh score appeared to be the worst, while the accuracy of MELD was almost identical with that of modified Child-Pugh in predicting short-term and slightly better in predicting medium-term survival. In Cox regression analysis, all four scores were significantly associated with survival, while MELD and creatinine-modified Child-Pugh scores had better predictive values (c-statistics: 0.73 and 0.69-0.70) than Child-Pugh score (c-statistics: 0.65). Adjustment for gamma-glutamate transpeptidase levels increased the predictive values of all systems (c-statistics: 0.77-0.81). Analysis of the expected and observed survival curves in patients subgroups according to their prognosis showed that all models fit the data reasonably well with MELD probably discriminating better the subgroups with worse prognosis.

CONCLUSION: MELD compared to the old Child-Pugh and particularly to creatinine-modified Child-Pugh scores does not appear to offer a clear advantage in predicting survival in patients with decompensated cirrhosis in daily clinical practice.

Development of the allocation system for deceased donor liver transplantation

As the number of pre- and post-transplant solid organ recipients continues to grow, it becomes important for all physicians to have an understanding of the process of organ procurement and allocation. In the United States, the current system for allocation and transplantation of human solid organs has been heavily influenced by the experience in deceased donor liver transplantation (DDLT). This review highlights the significant changes that have occurred over the past 10 years in DDLT, with specific attention to the impact of the Model for Endstage Liver Disease (MELD) score on organ allocation and pre- and post-transplant survival. DDLT is managed by the United Network for Organ Sharing (UNOS) which oversees organ procurement and allocation across geographically defined Organ Procurement Organizations (OPOs). For many years, deceased donor livers were allocated to waiting list patients based on subjective parameters of disease severity and accrued waiting time. In addition, organs have traditionally been retained within the OPO where they are procured contributing to geographic disparities in disease severity at the time of transplantation among deceased donor recipients. In response to a perceived unfairness in organ allocation, Congress issued its "Final Rule" in 1998. The Rule called for a more objective ranking of waiting list patients and more parity in disease severity among transplant recipients across OPOs. To date, little progress has been made in eliminating geographic inequities. Patients in the smallest OPOs continue to receive liver transplants at a lower level of disease severity. However, strides have been made to standardize assessments of disease severity and better prioritize waiting list patients. The MELD score has emerged as an excellent predictor of short-term mortality in patients with advanced liver disease, and patients listed for liver transplantation are now ranked based on their respective MELD scores. This has improved organ access to the most severely ill patients without compromising waiting list mortality or post-transplant survival. The current system for DDLT remains imperfect but has improved significantly in the past decade. As the number of patients in need of DDLT grows, the system will continue to evolve to meet this increasing demand.

Can inclusion of serum creatinine values improve the Child-Turcotte-Pugh score and challenge the prognostic yield of the model for end-stage liver disease score in the short-term prognostic assessment of cirrhotic patients?

BACKGROUND

The model for end-stage liver disease (MELD) score is a useful tool to assess prognosis in critically ill cirrhotic patients. However, its short-term prognostic superiority over the traditional Child-Turcotte-Pugh (CTP) score has not been definitely confirmed. The creatinine serum level is an important predictor of survival in patients with liver cirrhosis.

AIMS

To evaluate and compare the short-term prognostic accuracy of the CTP, the creatinine-modified CTP, and the MELD scores in patients with liver cirrhosis.

METHODS

CTP, creatinine-modified CTP, and MELD scores were calculated in a cohort of 145 cirrhotic patients. The creatinine-modified CTP was calculated as follows: we assessed the mean creatinine serum level and standard deviation (SD) of the 145 study patients, then assigned a score of 1 to patients with creatinine serum levels < or = to the mean, a score of 2 to patients with creatinine levels between the mean and the mean+1 SD, and a score of 3 to patients with creatinine levels above the mean+1 SD. The creatinine-modified CTP was then calculated by simply adding each patients' creatinine score to their traditional CTP scores. We calculated and compared the accuracy (c-index) of the three parameters in predicting 3-month survival.

RESULTS

The creatinine-modified CTP score showed better prognostic accuracy as compared with the traditional CTP (P=0.049). However, the MELD score proved to be better at defining patients' prognosis in the short-term as compared with both the traditional CTP score (P=0.012) and the creatinine-modified CTP (P=0.047). The excellent short-term prognostic accuracy of the MELD score was confirmed even when patients with abnormal creatinine serum levels were excluded from the analysis (c-index=0.935).

CONCLUSIONS

Adding creatinine values to the CTP slightly improves the prognostic usefulness of the traditional CTP score alone. The MELD score has a short-term prognostic yield that is better than what is provided by both the CTP and CTP creatinine-modified scores, even in cirrhotic patients who are not critically ill. The positive results obtained by using the MELD score were confirmed even after excluding patients with impaired renal function.

Application of an end-stage liver disease model in prediction of prognosis in patients with liver cirrhosis

AIM: To evaluate the short- and medium-term prognosis of liver cirrhotic patients by using the model for end-stage liver disease (MELD).

METHODS: The data of 199 cirrhotic patients were analyzed with a cohort method retrospectively and the follow-up period was at least one year. Both MELD score and Child-Pugh score were computed for each patient according to the original formula on admission day. Area under of receiver operating characteristic curve (ROC) was used to compare the value of MELD score with Child-Pugh's for predicting the prognosis. Kaplan-Meier survival curves were made using the cut-offs identified by means of ROC. MELD values were correlated with Child-Pugh scores.

RESULTS: Thirty-seven patients died in three months, MELD scores and Child-Pugh scores for non-survivors (23.4± 9.90, 10.8±2.29) were higher than those for survivors (14.3± 4.66, 8.68±2.21) significantly (P < 0.001). Fifty-nine patients died within the first year, MELD scores and Child-Pugh scores for non-survivors (20.3±9.31, 10.3±2.32) were higher than those for survivors (14.0±5.11, 8.43±2.23) significantly (P < 0.001). Area under the ROC of MELD for 3 months (0.826) was significantly (P < 0.05) different from that of Child-Pugh (0.745), but there was no difference in area under the ROC for 1 year (P > 0.05) between MELD value (0.758) and Child-Pugh score (0.724). Survival curves showed both MELD and Child-Pugh scores was clearly discriminated between patients who survived and those who died in short term as well as in the medium term (P < 0.001). MELD grading system showed significant correlation with Child-Pugh scores (r = 0.69, P < 0.001).

CONCLUSION: MELD grading is an objective predictive system for both short- and medium- term survival. It is more efficient than Child-Pugh score for short-term prognosis and is worth using in clinical setting.

Effects of treatment of hepatorenal syndrome before transplantation on posttransplantation outcome. A case-control study

BACKGROUND

Pretransplant renal function is the major determinant of survival after liver transplantation (LTx). Patients with hepatorenal syndrome (HRS) have a poor outcome after LTx compared with patients transplanted without HRS.

AIM

To analyze the impact of treatment of HRS before LTx on outcome after transplantation.

METHODS

The outcome of patients with HRS (n=9) treated with vasopressin analogues before LTx was compared with that of a contemporary control group of patients without HRS (n=27) matched by age, severity of liver failure, and type of immunosuppression.

RESULTS

Cases and controls were similar with respect to pretransplantation characteristics. Three-year survival probability was similar between the two groups (HRS-treated: 100% vs control: 83%, P=0.15). No significant differences were found between the two groups with respect to the incidence of impairment of renal function after LTx (HRS-treated: 22% vs control: 30%), severe infections (22 vs 33%), acute rejection (33 vs 41%), days in Intensive Care Unit (6+/-1 vs 8+/-1), days in hospital (27+/-4 vs 31+/-4), and transfusion requirements (11+/-3 vs 10+/-2 units).

CONCLUSIONS

Patients with HRS treated with vasopressin analogues before LTx have a posttransplantation outcome similar to that of patients transplanted with normal renal function. These results suggest that HRS should be treated before LTx.

Validation and refinement of survival models for liver retransplantation

Orthotopic liver retransplantation (re-OLT) is highly controversial. The objectives of this study were to determine the validity of a recently developed United Network for Organ Sharing (UNOS) multivariate model using an independent cohort of patients undergoing re-OLT outside the United States, to determine whether incorporation of other variables that were incomplete in the UNOS registry would provide additional prognostic information, to develop new models combining data sets from both cohorts, and to evaluate the validity of the model for end-stage liver disease (MELD) in patients undergoing re-OLT. Two hundred eighty-one adult patients undergoing re-OLT (between 1986 and 1999) at 6 foreign transplant centers comprised the validation cohort. We found good agreement between actual survival and predicted survival in the validation cohort; 1-year patient survival rates in the low-, intermediate-, and high-risk groups (as assigned by the original UNOS model) were 72%, 68%, and 36%, respectively (P <.0001). In the patients for whom the international normalized ratio (INR) of prothrombin time was available, MELD correlated with outcome following re-OLT; the median MELD scores for patients surviving at least 90 days compared with those dying within 90 days were 20.75 versus 25.9, respectively (P =.004). Utilizing both patient cohorts (n = 979), a new model, based on recipient age, total serum bilirubin, creatinine, and interval to re-OLT, was constructed (whole model chi(2) = 105, P <.0001). Using the c-statistic with 30-day, 90-day, 1-year, and 3-year mortality as the end points, the area under the receiver operating characteristic (ROC) curves for 4 different models were compared. In conclusion, prospective validation and use of these models as adjuncts to clinical decision making in the management of patients being considered for re-OLT are warranted.

Trans-catheter arterial chemoembolisation for hepatocellular carcinoma in patients with viral cirrhosis: role of combined staging systems, Cancer Liver Italian Program (CLIP) and Model for End-stage Liver Disease (MELD), in predicting outcome after treatment

BACKGROUND

Trans-catheter arterial chemoembolisation (TACE) is the most common palliative treatment for hepatocellular carcinoma (HCC). The therapeutic options depend both on the characteristics of the tumour and on functional staging of the cirrhosis.

AIM

To evaluate the effects of TACE on the survival of cirrhotic patients with HCC according to different staging systems [Okuda score, Cancer Liver Italian Program (CLIP) score, Model for End-stage Liver Disease (MELD) score] and in relation to the side-effects of TACE.

METHODS

Fifty cirrhotic patients, 36 CTP class A and 14 class B, underwent 106 TACE treatments with mitoxantrone. Survival at 12, 24, and 36 months was evaluated.

RESULTS

MELD at 12 months and CLIP at 24 months were identified as significant variables associated with survival. Combined cut-offs of CLIP and of MELD identified four subgroups of patients with different survivals, at 12, 24 and 36 months, respectively: CLIP >or= 2 and MELD >or= 10 (63%, 20% and 0%), CLIP < 2 and MELD >or= 10 (73%, 40% and 22%), CLIP >or= 2 and MELD < 10 (73%, 40% and 22%) and CLIP < 2 and MELD < 10 (100%, 63% and 50%). Post-TACE side-effects proved to have no influence on survival.

CONCLUSION

In patients with poor probability of survival (CLIP >or= 2 and MELD >or= 10), TACE must be planned with a great deal of caution, while in patients with possibly good outcomes (CLIP < 2 and MELD < 10), more 'aggressive' therapy should be taken into consideration.