Early transplantation maximizes survival in severe acute-on-chronic liver failure: Results of a Markov decision process model

Reduced short-term survival following liver transplant in patients with acute-on-chronic liver failure: Reevaluating OPTN data

BACKGROUND

Prior studies show severe acute-on-chronic liver failure (ACLF) at liver transplantation (LT) negatively impacts short-term, but not long-term, post-LT outcomes. However, not accounting for ACLF's time-varying effect on the waitlist may underappreciate its dynamic nature. Moreover, excluding those who died or dropped off the waitlist raises concerns about selection bias.

METHODS

This US nationwide retrospective cohort study estimated the effect of severe ACLF (grade 3) (ACLF-3) on post-LT outcomes, including adult, first-time deceased donor LT candidates listed from June 2013 to May 2023. A marginal structural model (MSM) to address selection bias and time-varying exposure (ACLF-3) was applied, with extended Cox proportional hazard models using a Heaviside step function to assess the hazard of death after LT.

RESULTS

Among 31,267 eligible candidates for LT (baseline cohort), 11.3% (n = 3518) had ACLF-3 at listing; 13.6% (n = 4243) died or dropped out while on the LT waitlist. Of the 27,024 patients who received LT (transplanted cohort), 12.3% (n = 3333) had ACLF-3 at LT. ACLF-3 at LT (but not at waitlisting) was associated with a higher hazard of death, with the hazard ratio of 1.80 (95% CI: 1.09-2.97) within 1 year after LT but not thereafter. This marginal structural model effect size was 9% higher than conventional multivariable Cox proportional hazard models. Sensitivity analyses corroborated these findings.

CONCLUSIONS

Compared to previous studies, ACLF-3 at LT in our marginal structural model was associated with a discernible increase in short-term mortality after transplant, presumably due to our addressing of selection bias, while long-term survival was similar to those without severe ACLF at LT. However, potential vulnerability to posttransplant complications warrants further investigation.

Extracorporeal liver support and liver transplantation for acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is defined by acute decompensation, organ failure and a high risk of short-term mortality. This condition is characterized by an overwhelming systemic inflammatory response. Despite treating the precipitating event, intensive monitoring and organ support, clinical deterioration can occur with very poor outcomes. During the last decades, several extracorporeal liver support systems have been developed to try to reduce ongoing liver injury and provide an improved environment for the liver to regenerate or as a bridging therapy until liver transplantation. Several clinical trials have been performed to evaluate the clinical efficacy of extracorporeal liver support systems, but no clear impact on survival has been proven. DIALIVE is a novel extracorporeal liver support device that has been built to specifically address the pathophysiological derangements responsible for the development of ACLF by replacing dysfunctional albumin and removing pathogen and damage-associated molecular patterns (PAMPs and DAMPs). In phase II clinical trial, DIALIVE appears to be safe, and it seems to be associated with a faster time to the resolution of ACLF compared with standard medical treatment. Even in patients with severe ACLF, liver transplantation saves lives and there is clear evidence of transplant benefit. Careful selection of patients is required to attain good results from liver transplantation, but many questions remain unanswered. In this review, we describe the current perspectives on the use of extracorporeal liver support and liver transplantation for ACLF patients.

Mechanisms and treatment approaches for ACLF

Acute-on-chronic liver failure (ACLF) is a life-threatening syndrome characterized by decompensation of cirrhosis, severe systemic inflammation and organ failures. ACLF is frequently triggered by intra- and/or extrahepatic insults, such as bacterial infections, alcohol-related hepatitis or flares of hepatic viruses. The imbalance between systemic inflammation and immune tolerance causes organ failures through the following mechanisms: (i) direct damage of immune cells/mediators; (ii) worsening of circulatory dysfunction resulting in organ hypoperfusion and (iii) metabolic alterations with prioritization of energetic substrates for inflammation and peripheral organ 'energetic crisis'. Currently, the management of ACLF includes the support of organ failures, the identification and treatment of precipitating factors and expedited assessment for liver transplantation (LT). Early LT should be considered in patients with ACLF grade 3, who are unlikely to recover with the available treatments and have a mortality rate > 70% at 28 days. However, the selection of transplant candidates and their prioritization on the LT waiting list need standardization. Future challenges in the ACLF field include a better understanding of pathophysiological mechanisms leading to inflammation and organ failures, the development of specific treatments for the disease and personalized treatment approaches. Herein, we reviewed the current knowledge and future perspectives on mechanisms and treatment of ACLF.

Management of the acute on chronic liver failure in the intensive care unit

Acute on chronic liver failure (ACLF) reflects the development of organ failure(s) in a patient with cirrhosis and is associated with high short-term mortality. Given that ACLF has many different 'phenotypes', medical management needs to take into account the relationship between precipitating insult, organ systems involved and underlying physiology of chronic liver disease/cirrhosis. The goals of intensive care management of patients suffering ACLF are to rapidly recognize and treat inciting events (e.g. infection, severe alcoholic hepatitis and bleeding) and to aggressively support failing organ systems to ensure that patients may successfully undergo liver transplantation or recovery. Management of these patients is complex since they are prone to develop new organ failures and infectious or bleeding complications. ICU therapy parallels that applied in the general ICU population in some complications but differs in others. Given that liver transplantation in ACLF is an emerging and evolving field, multidisciplinary teams with expertise in critical care and transplant medicine best accomplish management of the critically ill ACLF patient. The focus of this review is to identify the common complications of ACLF and to describe the proper management in critically ill patients awaiting liver transplantation in our centres, including organ support, prognostic assessment and how to assess when recovery is unlikely.

Psychosocial Determinants and Outcomes of Expedited Liver Transplant Evaluations: Insights From a Retrospective Cohort Analysis

BACKGROUND

As the burden of chronic liver disease and the demand for liver transplants (LT) grows, understanding the interplay between access to care and patient outcomes is increasingly important. In this study, we explored patient characteristics and transplant outcomes in patients undergoing LT evaluations, with a focus on identifying risk factors for expedited LT evaluation.

METHODS

This single-center retrospective cohort study included patients who underwent LT evaluation for deceased donor LT between October 2017 and July 2021. Patients were categorized by context: expedited (inpatient) and routine (outpatient) LT evaluation groups. The outcome measures included waitlist status, pre-LT mortality, and post-LT complications.

RESULTS

Of 602 patients, 26% underwent expedited LT evaluation. Patients who underwent expedited evaluation were more likely to have a history of ascites (P < 0.001), hepatic encephalopathy (P < 0.001), and spontaneous bacterial peritonitis (P < 0.001) and had a higher model for end-stage liver disease sodium scores (P < 0.001). Both mortality (35% versus 17%, P < 0.001) and LT (39% versus 22%, P < 0.001) were more common in the expedited group; post-LT mortality was similar up to 2 y. Perceived financial concerns and social security disability income were risk factors for expedited LT evaluation. In addition, greater proximity to the LT center (95% confidence interval, 1.1-6.3; P = 0.025) and speaking a primary language other than English (95% confidence interval, 1.0-10.7; P = 0.042) were risk factors for expedited LT evaluation in women but not in men.

CONCLUSIONS

Expedited LT evaluations were associated with more severe illness and higher pre-LT mortality; however, post-LT outcomes were comparable with those of routine evaluations. Identifying psychosocial risk factors may enhance equity and access to LT evaluations, particularly for women who face unique challenges in this context.

AKI in ACLF: navigating the complex therapeutic puzzle

INTRODUCTION

Acute kidney injury (AKI) in patients with acute-on-chronic liver failure (ACLF) is driven by the severity of systemic inflammation, acute portal hypertension driving circulatory dysfunction, hyperbilirubinemia, and toxicity of bile acids. The spectrum is mostly structural, associated with reduced response to vasoconstrictors. The progression is rapid, and need of renal replacement therapy and extracorporeal therapies may be required for the management. The development of renal failure is usually considered when defining the syndrome of ACLF.

AREAS COVERED

In the current review we discuss the pathophysiological basis, natural course, and response to the current therapeutic modalities and challenges in assessing and managing AKI in patients with ACLF. We conducted a comprehensive search of electronic databases such as PubMed, Web of Science, and Scopus using keywords like lactate, NGAL, and PHTN, as well as CRRT, PLEX, ACLF, and AKI phases for our review. Peer-reviewed English papers that addressed our issue were considered.

EXPERT OPINION

The difficulties and specific management strategies for AKI in ACLF patients are discussed emphasizing the importance of customized protocols, risk assessment guided by biomarkers, and investigation of extracorporeal therapies that target bile acids.

APASL clinical practice guidelines on the management of acute kidney injury in acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a syndrome that is characterized by the rapid development of organ failures predisposing these patients to a high risk of short-term early death. The main causes of organ failure in these patients are bacterial infections and systemic inflammation, both of which can be severe. For the majority of these patients, a prompt liver transplant is still the only effective course of treatment. Kidneys are one of the most frequent extrahepatic organs that are affected in patients with ACLF, since acute kidney injury (AKI) is reported in 22.8-34% of patients with ACLF. Approach and management of kidney injury could improve overall outcomes in these patients. Importantly, patients with ACLF more frequently have stage 3 AKI with a low rate of response to the current treatment modalities. The objective of the present position paper is to critically review and analyze the published data on AKI in ACLF, evolve a consensus, and provide recommendations for early diagnosis, pathophysiology, prevention, and management of AKI in patients with ACLF. In the absence of direct evidence, we propose expert opinions for guidance in managing AKI in this very challenging group of patients and focus on areas of future research. This consensus will be of major importance to all hepatologists, liver transplant surgeons, and intensivists across the globe.

Evolution of Liver Transplantation Indications: Expanding Horizons

Liver transplantation (LT) has significantly transformed the prognosis of patients with end-stage liver disease and hepatocellular carcinoma (HCC). The traditional epidemiology of liver diseases has undergone a remarkable shift in indications for LT, marked by a decline in viral hepatitis and an increase in metabolic dysfunction-associated steatotic liver disease (MASLD), along with expanded indications for HCC. Recent advancements in surgical techniques, organ preservation and post-transplant patients' management have opened new possibilities for LT. Conditions that were historically considered absolute contraindications have emerged as potential new indications, demonstrating promising results in terms of patient survival. While these expanding indications provide newfound hope, the ethical dilemma of organ scarcity persists. Addressing this requires careful consideration and international collaboration to ensure equitable access to LT. Multidisciplinary approaches and ongoing research efforts are crucial to navigate the evolving landscape of LT. This review aims to offer a current overview of the primary emerging indications for LT, focusing on acute-on-chronic liver failure (ACLF), acute alcoholic hepatitis (AH), intrahepatic and perihilar cholangiocarcinoma (i- and p-CCA), colorectal liver metastasis (CRLM), and neuroendocrine tumor (NET) liver metastases.

[Transplantation for acute-on-chronic liver failure]

A review and discussion of the current literature on liver transplantation for acute-on-chronic liver failure (ACLF) was performed. The ACLF represents an acute deterioration of liver function with pre-existing liver disease and is associated with increasing multiorgan failure, depending on the stage. The 28-day mortality ranges to well over 70% in stage 3 and requires rapid intensive medical treatment involving an interdisciplinary team experienced in transplantation medicine. Under optimized conditions, liver transplantation provides long-term survival rates comparable to other indications. Achieving this requires a differentiated donor selection, choosing the appropriate time for transplantation in the context of a dynamic disease course and the use of appropriate surgical techniques.

Acute-On-Chronic Liver Failure: Current Interventional Treatment Options and Future Challenges

Acute-on-chronic liver failure (ACLF) is a frequent complication in patients with liver cirrhosis that has high short-term mortality. It is characterized by acute decompensation (AD) of liver cirrhosis, intra- and extrahepatic organ failure, and severe systemic inflammation (SI). In the recent past, several studies have investigated the management of this group of patients. Identification and treatment of precipitants of decompensation and ACLF play an important role, and management of the respective intra- and extrahepatic organ failures is essential. However, no specific treatment for ACLF has been established to date, and the only curative treatment option currently available for these patients is liver transplantation (LT). It has been shown that ACLF patients are at severe risk of waitlist mortality, and post-LT survival rates are high, making ACLF patients suitable candidates for LT. However, only a limited number of patients are eligible for LT due to related contraindications such as uncontrolled infections. In this case, bridging strategies (e.g., extracorporeal organ support systems) are required. Further therapeutic approaches have recently been developed and evaluated. Thus, this review focuses on current management and potential future treatment options.

Liver Transplantation Within 7-Days of Listing Improves Survival in ACLF-3

BACKGROUND AND AIMS

Patients with acute on chronic liver failure (ACLF-3) have a very high short-term mortality without liver transplantation (LT). Our objective was to determine whether early LT (ELT; ≤ 7 days from listing) had an impact on 1 year patient (PS) in patients with ACLF-3 compared to late LT (LLT; days 8-28 from listing).

METHODS

All adults with ACLF-3 listed for LT with the United Network for Organ Sharing (UNOS) between 2005 and 2021 were included. We excluded status one patients and those with liver cancer or listed for multi-organ or living donor transplants. ACLF patients were identified using the European Association for the Study of the Liver-Chronic Liver Failure criteria. Patients were categorized as ACLF-3a and ACLF-3b.

RESULTS

During the study period, 7607 patients were listed with ACLF-3 (3a-4520, 3b-3087); 3498 patients with ACLF-3 underwent ELT and 1308 had LLT. The overall 1 year PS after listing was 64.4% in ACLF-3a and 50% in ACLF-3b. In 4806 ACLF-3 patients who underwent LT, 1 year PS was 86.2%, but those who had ELT had higher survival (87.1 vs. 83.6%, P = 0.001) than the LLT group. These survival benefits were seen in both ACLF-3a and ACLF-3b. On multivariable analysis, age (HR 1.02, CI 1.01-1.03), diabetes (HR 1.40, CI 1.16-1.68), respiratory failure (HR 1.76, CI 1.50-2.08), donor risk index > 1.7 (HR 1.24, CI 1.06-1.45), and LLT (HR 1.20, CI 1.02-1.43) were independent predictors of higher 1 year mortality while higher albumin (HR 0.89, CI 0.80-0.98) was associated with reduced mortality.

CONCLUSION

Early LT (≤ 7 days from listing) in ACLF-3 is associated with better 1 year survival compared to late LT (days 8-28 from listing).

Critical Care Management of Acute-on-Chronic Liver Failure: Certainties and Unknowns

Intensive care unit (ICU) admission is frequently required in patients with decompensated cirrhosis for organ support. This entity, known as acute-on-chronic liver failure (ACLF), is associated with high short-term mortality. ICU management of ACLF is complex, as these patients are prone to develop new organ failures and infectious or bleeding complications. Poor nutritional status, lack of effective liver support systems, and shortage of liver donors are also factors that contribute to increase their mortality. ICU therapy parallels that applied in the general ICU population in some complications but has differential characteristics in others. This review describes the current knowledge on critical care management of patients with ACLF including organ support, prognostic assessment, early liver transplantation, and futility rules. Certainties and knowledge gaps in this area are also discussed.

Current and future perspectives on acute-on-chronic liver failure: Challenges of transplantation, machine perfusion, and beyond

Acute-on-chronic liver failure (ACLF) is a syndrome that occurs in patients with chronic liver disease and is characterized by acute decompensation, organ failure and high short-term mortality. Partially due to the lack of universal diagnostic criteria, the actual ACLF prevalence remains unclear; nevertheless, it is expected to be a highly prevalent condition worldwide. Earlier transplantation is an effective protective measure for selected ACLF patients. Besides liver trans-plantation, diagnosing and treating precipitant events and providing supportive treatment for organ failures are currently the cornerstone of ACLF therapy. Although new clinical specific therapies have been researched, more studies are necessary to assess safety and efficacy. Therefore, future ACLF management strategies must consider measures to improve access to liver transplantation because the time window for this life-saving therapy is frequently narrow. Thus, an urgent and global discussion about allocation and prioritization for transplantation in critically ill ACLF patients is needed because there is evidence suggesting that the current model may not portray their waitlist mortality. In addition, while donor organ quality is meant to be a prognostic factor in the ACLF setting, recent evidence suggests that machine perfusion of the liver may be a safe tool to improve the donor organ pool and expedite liver transplantation in this scenario.

Liver transplantation in Acute-on-Chronic liver failure: Timing of transplantation and selection of patient population

Acute-on-Chronic liver failure (ACLF) is a clinical syndrome with high short-term mortality. Alcoholic ACLF is prevalent in European and American countries, while hepatitis B virus (HBV)-related ACLF is more common in the Asia-Pacific region. There is still a lack of a unified definition standard for ACLF, due to various etiologies and pathogeneses in different continents. Currently, liver transplantation (LT) is the most effective treatment for liver failure. However, the shortage of liver sources is still a global problem, which seriously limits the clinical application of an LT. Premature LT aggravates the shortage of liver resources to a certain extent, and too much delay significantly increases the risk of complications and death. Therefore, this study reviews the current literature on LT in the treatment of ACLF and discusses further the challenges for ACLF patients, the timing of LT for ACLF, and the choice of the patient population.

Liver transplantation is beneficial regardless of cirrhosis stage or acute-on-chronic liver failure grade: A single-center experience

BACKGROUND

Liver transplantation for the most critically ill remains controversial; however, it is currently the only curative treatment option.

AIM

To assess immediate posttransplant outcomes and compare the short (1 year) and long-term (6 years) posttransplant survival among cirrhotic patients stratified by disease severity.

METHODS

We included cirrhotic patients undergoing liver transplantation between 2015 and 2019 and categorized them into compensated cirrhosis (CC), decompensated cirrhosis (DC), and acute-on-chronic liver failure (ACLF). ACLF was further divided into severity grades. Our primary outcomes of interest were total days of intensive care unit (ICU) and hospital stay, development of complications and posttransplant survival at 1 and 6 years.

RESULTS

235 patients underwent liver transplantation (CC = 11, DC = 129 and ACLF = 95). Patients with ACLF had a significantly longer hospital stay [8.0 (6.0-13.0) vs CC, 6.0 (3.0-7.0), and DC 7.0 (4.5-10.0); P = 0.01] and developed more infection-related complications [47 (49.5%), vs CC, 1 (9.1%) and DC, 38 (29.5%); P < 0.01]. Posttransplant survival at 1- and 6-years was similar among groups (P = 0.60 and P = 0.90, respectively). ACLF patients stratified according to ACLF grade [ACLF-1 n = 40 (42.1%), ACLF-2 n = 33 (34.7%) and ACLF-3 n = 22 (23.2%)], had similar ICU and hospital stay length (P = 0.68, P = 0.54), as well as comparable frequencies of overall and infectious post-transplant complications (P = 0.58, P = 0.80). There was no survival difference between ACLF grades at 1 year and 6 years (P = 0.40 and P = 0.15).

CONCLUSION

Patients may benefit from liver transplantation regardless of the cirrhosis stage. ACLF patients have a longer hospital stay and frequency of infectious complications; however, excellent, and comparable 1 and 6-year survival rates support their enlisting and transplantation including those with ACLF-3.

High-risk liver transplant recipients with grade 3 acute on chronic liver failure should receive the good quality graft

BACKGROUND & AIM

We aimed to develop a risk score for LT recipients and donor selection among patients with ACLF-3.

METHODS AND RESULTS

A total of 7166 adult LT recipients (mean age 53 years, 63% males, 56% Caucasians, 42% obese, median MELD score 36.5) using deceased donor grafts in the UNOS database (01/2002-06/2018) who were in ACLF-3 at LT as per EASL-CLIF criteria were analysed. Cox regression model on the derivation dataset (N = 3583) showed recipient age, non-alcohol aetiology, pulmonary failure, brain failure and cardiovascular failure to be associated with 1-year patient survival. Observed and expected post-transplant 1-year survival showed excellent correlation (R = .920). Risk score from cox model on derivation dataset stratified 3583 recipients in validation cohort using cut-off scores 7.55 and 11.57 to low (N = 1211), medium (N = 1168) and high risk (N = 1199), with 1-year patient survival of 89%, 82% and 80% respectively. Based on poor versus good quality graft (donor risk index cut-off at 1.50), 1-year patient survival for low, medium and high-risk categories were 90 versus 89% (p = .490), 83 versus 82% (p = .390) and 83 versus 78% (p = .038) respectively. Among recipients with a high-risk score, donor factors of age ≥60 years, grafts obtained from national sharing and macro-steatosis >15% were associated with 1-year patient survival below 66%.

CONCLUSION

Among ACLF-3 liver transplant recipients, those with high risk at the time of transplant receiving better quality graft will improve post-transplant outcomes. Prospective studies using additional characteristics are needed to derive an accurate risk score model in predicting post-transplant outcomes among recipients with ACLF-3.

PRO: Patients With Acute-on-Chronic Liver Failure Should Receive Priority on the Liver Transplant Waiting List

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Transplantation in Acute-on-Chronic Liver Failure: Feasibility and Futility

Content available: Author Interview and Audio Recording.

Surgical Considerations Regarding Transplantation for the Patient With Acute-on-Chronic Liver Failure

Content available: Author Audio Recording.