Model for end-stage liver disease (MELD) exception for hepatic encephalopathy

Impact of hepatic encephalopathy on liver transplant waiting list mortality in regions with different transplantation rates

Overt hepatic encephalopathy (OHE) negatively impacts the prognosis of liver transplant candidates. However, it is not taken into account in most prioritizing organ allocation systems. We aimed to assess the impact of OHE on waitlist mortality in 3 cohorts of cirrhotic patients awaiting liver transplantation, with differences in the composition of patient population, transplantation policy, and transplantation rates. These cohorts were derived from two centers in the Netherlands (reference and validation cohort, n = 246 and n = 205, respectively) and one in Spain (validation cohort, n = 253). Competing-risk regression analysis was applied to assess the association of OHE with 1-year waitlist mortality. OHE was found to be associated with mortality, independently of MELD score, other cirrhosis-related complications and hepatocellular carcinoma (HCC; sHR = 4.19, 95% CI = 1.9-9.5, P = 0.001). The addition of extra MELD points for OHE counteracted its negative impact on survival. These findings were confirmed in the Dutch validation cohort, whereas in the Spanish cohort, containing a significantly greater proportion of HCC and with higher transplantation rates, OHE was not associated with mortality. In conclusion, OHE is an independent risk factor for 1-year waitlist mortality and might be a prioritization rule for organ allocation. However, its impact seems to be attenuated in settings with significantly higher transplantation rates.

Waitlist Outcomes in Liver Transplant Candidates with High MELD and Severe Hepatic Encephalopathy

BACKGROUND

Organ Procurement and Transplantation Network and United Network for Organ Sharing (OPTN/UNOS) implemented the Share 35 policy in June 2013 to prioritize the sickest patients awaiting liver transplantation (LT). However, Model for End-Stage Liver Disease (MELD) score does not incorporate hepatic encephalopathy (HE), an independent predictor of waitlist mortality.

AIM

To evaluate the impact of severe HE (grade 3-4) on waitlist outcomes in MELD ≥ 30 patients.

METHODS

Using the OPTN/UNOS database, we evaluated LT waitlist registrants from 2005-2014. Demographics, comorbidities, and waitlist survival were compared between four cohorts: MELD 30-34 with severe HE, MELD 30-34 without severe HE, MELD ≥ 35 with severe HE, and MELD ≥ 35 without severe HE.

RESULTS

Among 10,003 waitlist registrants studied, 41.6% had MELD score 30-34 and 58.4% had MELD ≥ 35. Patients with severe HE had a higher 90-day waitlist mortality in both MELD 30-34 (severe HE 71.1% vs. no HE 56.6%; p < 0.001) and MELD ≥ 35 subgroups (severe HE 85% versus no HE 74.2%; p < 0.001). MELD 30-34 patients with severe HE had similar 90-day waitlist mortality as MELD ≥ 35 patients without severe HE (71.1 vs. 74.2%, respectively; p = 0.35). On multivariate Cox proportional hazards modeling, MELD ≥ 30 patients had 58% greater risk of 90-day waitlist mortality than those without severe HE (HR 1.58, 95% CI 1.53-1.62; p < 0.001).

CONCLUSION

Patients awaiting LT with MELD score of 30-34 and severe HE should receive priority status for organ allocation with exception MELD ≥ 35.

From Child-Pugh to Model for End-Stage Liver Disease: Deciding Who Needs a Liver Transplant

This article reviews the historical evolution of the liver transplant organ allocation policy and the indications/contraindications for liver transplant, and provides an overview of the liver transplant evaluation process. The article is intended to help internists determine whether and when referral to a liver transplant center is indicated, and to help internists to counsel patients whose initial evaluation at a transplant center is pending.

The impact of pretransplant hepatic encephalopathy on survival following liver transplantation

Hepatic encephalopathy (HE) is a surrogate marker of liver disease severity, and more severe HE is associated with higher mortality among patients with chronic liver disease. However, whether severity of HE at the time of liver transplantation (LT) directly impacts post-LT survival or whether this suspected mortality linkage is due to more severe liver disease and subsequently higher rates of post-LT infection is not well defined. Using population-based data from the 2003 to 2013 United Network for Organ Sharing registry, we evaluated the impact of HE at the time of LT on post-LT survival among adults in the United States. Survival was stratified by HE severity (none, grade 1-2, grade 3-4) and Model for End-Stage Liver Disease score and was evaluated using Kaplan-Meier methods and multivariate Cox proportional hazards models. From 2003 to 2013, 59,937 patients underwent LT (36.1%, no HE; 53.8%, grade 1-2 HE; 10.2%, grade 3-4 HE). Compared to no HE, patients with grade 3-4 HE had significantly lower overall post-LT survival (1-year, 82.5% versus 90.3%; P < 0.001; 5-year, 69.1% versus 74.4%; P < 0.001). On multivariate regression, grade 3-4 HE was independently associated with lower overall post-LT survival (HR, 1.27; 95% CI, 1.17-1.39; P < 0.001). However, the increased mortality associated with HE is observed primarily within the first year following LT and was a reflection of higher rates of infection-related deaths among patients with more severe HE. In conclusion, grade 3-4 HE at the time of LT is associated with lower post-LT survival, with a proposed direct or indirect association of more severe HE before LT with increased rates of post-LT infections. Increased awareness and vigilance toward treating HE before LT and more aggressive monitoring and treatment for infections in the perioperative setting may improve LT outcomes.

Model for End-Stage Liver Disease and liver cirrhosis-related complications

The Model for End-Stage Liver Disease (MELD) score has gained wide acceptance for predicting survival in patients undergoing liver transplantation. The strength of this score remains in the mathematical formula derived from a multivariate Cox regression analysis; it is a continuous scale and lacks a ceiling or a floor effect with a wide range of discrimination. It is based on objective, reproducible, and readily available laboratory data and the wide range of samples which have been validated. Liver cirrhosis complications such as ascites, encephalopathy, spontaneous bacterial peritonitis and variceal bleeding were not considered in the MELD score underestimating their direct association with the severity of liver disease. In this regard, several recent studies have shown that clinical manifestations secondary to portal hypertension are good prognostic markers in cirrhotic patients and may add additional useful prognostic information to the current MELD. We review the feasibility of MELD score as a prognostic predictor in patients with liver cirrhosis-related complications.

Liver transplantation in adults: Choosing the appropriate timing

Liver transplantation is indicated in patients with acute liver failure, decompensated cirrhosis, hepatocellular carcinoma and rare liver-based genetic defects that trigger damage of other organs. Early referral to a transplant center is crucial in acute liver failure due to the high mortality with medical therapy and its unpredictable evolution. Referral to a transplant center should be considered when at least one complication of cirrhosis occurs during its natural history. However, because of the shortage of organ donors and the short-term mortality after liver transplantation on one hand and the possibility of managing the complications of cirrhosis with other treatments on the other, patients are carefully selected by the transplant center to ensure that transplantation is indicated and that there are no medical, surgical and psychological contraindications. Patients approved for transplantation are placed on the transplant waiting list and prioritized according to disease severity. Thus, the appropriate timing of transplantation depends on recipient disease severity and, although this is still a matter of debate, also on donor quality. These two variables are known to determine the “transplant benefit” (i.e., when the expected patient survival is better with, than without, transplantation) and should guide donor allocation.

Clinical efficacy and safety of lactulose for minimal hepatic encephalopathy: a meta-analysis

OBJECTIVE

To evaluate the clinical efficacy of lactulose in patients with minimal hepatic encephalopathy (MHE).

METHODS

Randomized controlled trials (RCTs) comparing lactulose with placebo or with no intervention in the management of MHE that were conducted from January 1990 to July 2011 were searched from MEDLINE, EMBASE, SCI, Cochrane Controlled Trials Register, and China Biological Medicine Database. Studies with a Jadad score higher than 3 were included in the meta-analysis and evaluated using RevMan5.0 software for relative risk (RR) or weighted mean difference (WMD) with 95% confidence intervals (95% CI). Sensitivity analysis was performed on the ethnical differences and quality of the trials. Publication bias was observed using an inverted funnel plot.

RESULTS

Nine studies with 434 patients were included in the meta-analysis. Compared with placebo or no intervention, lactulose significantly reduced the risk of no improvement in neuropsychological tests (RR: 0.52, 95% CI: 0.44-0.62, P<0.00001), the time required for the completion of the number connection test-A (WMD: -26.95, 95% CI: -37.81 to -16.10, P<0.00001), and the mean number of abnormal neuropsychological tests (WMD: -1.76, 95% CI: -1.96 to -1.56, P<0.00001). Furthermore, the meta-analysis also showed that lactulose prevented the progression to overt hepatic encephalopathy (RR: 0.17, 95% CI: 0.06-0.52, P=0.002), reduced blood ammonia levels (WMD: -9.89 µmol/l, 95% CI: -11.01 to -8.77 µmol/l, P<0.00001), and improve health-related quality of life (WMD: -6.05, 95% CI: -6.30 to -5.20, P<0.00001). However, no significant difference was observed in the mortality of patients with MHE (RR: 0.75, 95% CI: 0.21-2.72, P=0.66), and lactulose significantly increased the incidence of diarrhea (RR: 4.38, 95% CI: 1.35-14.25, P=0.01).

CONCLUSION

Lactulose has significant beneficial effects for patients with MHE compared with placebo or no intervention.