The novel SALT-M score predicts 1-year post-transplant mortality in patients with severe acute-on-chronic liver failure

Robust Predictive Performance of the SALT-M Score for Clinical Outcomes in Asian Patients With Acute-on-Chronic Liver Failure

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a syndrome of patients with chronic liver disease presenting with multiple organ failures. Recently, Sundaram-ACLF-LT Mortality (SALT-M) score has been developed to predict 1-year post-liver transplantation mortality. We validated the SALT-M score in a large-volume, Asian single-centre cohort.

AIMS

We validated the SALT-M score in a large-volume, Asian single-centre cohort.

METHODS

We analysed 224 patients of ACLF grade 2-3. Area under the receiver operating characteristic curve (AUROC) and concordance index (c-index) were used to assess and compare the predictability of posttransplant mortality of SALT-M and other scores. Moreover, we compared the survivals of patients with high and low SALT-M, in conjunction with MELD score and ACLF grade.

RESULTS

The AUROC for prediction of 1-year post-LT survival was higher in SALT-M (0.691) than in MELD, MELD-Na, MELD 3.0 and delta-MELD. Similarly, the c-index of the SALT-M (0.650) was higher than aforementioned MELD systems. When categorised by the cut-off of SALT-M ≥ 20 and MELD ≥ 30, patients with high SALT-M exhibited lower post-LT survival than those with low SALT-M scores regardless of high or low MELD (40.0% for high SALT-M/high MELD vs. 42.9% for high SALT-M/low MELD vs. 73.8% for low SALT-M/high MELD vs. 63.7% for low SALT-M/low MELD, p < 0.001). In patients with ACLF grade 3, SALT-M effectively stratified the posttransplant mortality (39.4% for high SALT-M vs. 63.1% for low SALT-M, p = 0.018).

CONCLUSIONS

SALT-M outperformed previous MELD systems for predicting posttransplant mortality in Asian LT cohort with severe ACLF. Transplantability for patients with severe ACLF could be determined based on SALT-M.

Common definitions and variables are needed for the United States to join the conversation on acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a variably defined syndrome characterized by acute decompensation of cirrhosis with organ failures. At least 13 different definitions and diagnostic criteria for ACLF have been proposed, and there is increasing recognition that patients with ACLF may face disadvantages in the current United States liver allocation system. There is a need, therefore, for more standardized data collection and consensus to improve study design and outcome assessment in ACLF. In this article, we discuss the current landscape of transplantation for patients with ACLF, strategies to optimize organ utility, and data opportunities based on emerging technologies to facilitate improved data collection.

Frailty and sarcopenia in patients with acute-on-chronic liver failure: Assessment and risk in the liver transplant setting

Frailty and sarcopenia are well-recognized factors related to worse outcomes in patients with cirrhosis, including liver transplant (LT) candidates. Implications of pre-LT functional and muscle deterioration also affect post-LT outcomes. Patients with cirrhosis and acute-on-chronic liver failure (ACLF) have a lower survival rate, both before and after LT. There is a need to better identify those patients with ACLF who would benefit from LT. This review aims to present the available data about frailty and sarcopenia in patients with ACLF in the LT setting. An exhaustive review of the published literature was conducted. Data regarding frailty and sarcopenia in LT candidates with ACLF are scarce and heterogeneous. Studies evaluating frailty and sarcopenia in critically ill patients outside the liver literature are also presented in this review to enrich the knowledge of this field in expansion. Frailty and sarcopenia seem to contribute to worse outcomes in LT candidates with ACLF, both before and after LT. Sarcopenia evaluation may be the most prudent approach for those very sick patients. Skeletal muscle index assessed by computed tomography is recommended to evaluate sarcopenia. The role of muscle ultrasound and bioelectrical impedance analysis is to be determined. Frailty and sarcopenia are crucial factors to consider on a case-by-case basis in LT candidates with ACLF to improve patient outcomes.

[Liver transplantation in acute and acute-on-chronic liver failure]

Acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) are diseases with a rapidly progressive course and high mortality. Apart from treating the underlying triggers and intensive care measures, there are very limited therapeutic options for either condition. Liver transplantation is often the only life-saving treatment, but it cannot always be employed due to contraindications and severe disease progression. ACLF is characterized by underlying liver cirrhosis and typical triggers such as bacterial infections, bleeding, or alcohol binges. ALF occurs in previously healthy livers, usually as a result of purely hepatotoxic events. Disease differences are also reflected in the course and regulations of liver transplantation. Newer prognostic parameters and prioritization programs for ACLF can help improve both waiting list mortality and outcomes after transplantation.

Benefits of liver transplant in critically ill patients with acute-on-chronic liver failure: Implementation of an urgent living-donor program

We evaluated the liver transplantation (LT) criteria in acute-on-chronic liver failure (ACLF), incorporating an urgent living-donor LT (LDLT) program. Critically ill patients with a Chronic Liver Failure Consortium (CLIF-C) ACLF score (CLIF-C_ACLF_score) ≥65, previously considered unsuitable for LT, were included to explore the excess mortality threshold of the CLIF-C_ACLF_score (CLIF-C_ACLF_score_threshold). We followed 854 consecutive patients with ACLF (276 ACLF grade 2 and 215 ACLF grade 3) over 10 years among 4432 LT recipients between 2008 and 2019. For advanced ACLF patients without immediate deceased-donor (DD) allocation, an urgent LDLT program was expedited. The CLIF-C_ACLF_score_threshold was determined by the metrics of transplant survival benefit: >60% 1-year and >50% 5-year survival rate. In predicting post-LT mortality, the CLIF-C_ACLF_score outperformed the (model for end-stage liver disease-sodium) MELD-Na and (model for end-stage liver disease) MELD-3.0 scores but was comparable to the Sundaram ACLF-LT-mortality score. A CLIF-C_ACLF_score ≥65 (n = 54) demonstrated posttransplant survival benefits, with 1-year and 5-year survival rates of 66.7% and 50.4% (P < .001), respectively. Novel CLIF-C_ACLF_score_threshold for 1-year and 5-year mortalities was 70 and 69, respectively. A CLIF-C_ACLF_score-based nomogram for predicting survival probabilities, integrating cardiovascular disease, diabetes, and donor type (LDLT vs DDLT), was generated. This study suggests reconsidering the criteria for unsuitable LT with a CLIF-C_ACLF_score ≥65. Implementing a timely salvage LT strategy, and incorporating urgent LDLT, can enhance survival rates.

Sex disparities in acute-on-chronic liver failure: From admission to the intensive care unit to liver transplantation

Acute-on-chronic liver failure (ACLF) is a severe clinical syndrome characterized by acute liver decompensation in patients with chronic liver disease, marked by systemic inflammation and systemic organ failure. In this review, we discussed sex-related disparities in the incidence, prognosis, and access to liver transplantation (LT) for patients with ACLF, particularly during Intensive Care Unit (ICU) management. Some studies have suggested that ACLF is more prevalent among male patients admitted to the ICU, and they have higher mortality rates than females. Available prognostic scores, such as CLIF-C or TAM-score, lack sex-specific adjustments. Sarcopenia seems to enhance the accuracy of these scores though this is observed only in male individuals. LT is the only effective treatment for patients with ACLF grade 2-3 who do not respond to medical therapies. Sex-related disparities occur in both access to LT and post-transplant outcomes, although the influence of sex on the prevalence, clinical course, and listing for LT in ACLF remains largely undetermined. A sex-orientated analysis of ICU outcomes in ACLF would facilitate the development of sex-orientated management strategies, thereby improving patients' outcomes.

Development and validation of prediction models for nosocomial infection and prognosis in hospitalized patients with cirrhosis

BACKGROUND

Nosocomial infections (NIs) frequently occur and adversely impact prognosis for hospitalized patients with cirrhosis. This study aims to develop and validate two machine learning models for NIs and in-hospital mortality risk prediction.

METHODS

The Prediction of Nosocomial Infection and Prognosis in Cirrhotic patients (PIPC) study included hospitalized patients with cirrhosis at the Qingchun Campus of the First Affiliated Hospital of Zhejiang University. We then assessed several machine learning algorithms to construct predictive models for NIs and prognosis. We validated the best-performing models with bootstrapping techniques and an external validation dataset. The accuracy of the predictions was evaluated through sensitivity, specificity, predictive values, and likelihood ratios, while predictive robustness was examined through subgroup analyses and comparisons between models.

RESULTS

We enrolled 1,297 patients into derivation cohort and 496 patients into external validation cohort. Among the six algorithms assessed, the Random Forest algorithm performed best. For NIs, the PIPC-NI model achieved an area under the curve (AUC) of 0.784 (95% confidence interval [CI] 0.741-0.826), a sensitivity of 0.712, and a specificity of 0.702. For in-hospital mortality, the PIPC- mortality model achieved an AUC of 0.793 (95% CI 0.749-0.836), a sensitivity of 0.769, and a specificity of 0.701. Moreover, our PIPC models demonstrated superior predictive performance compared to the existing MELD, MELD-Na, and Child-Pugh scores.

CONCLUSIONS

The PIPC models showed good predictive power and may facilitate healthcare providers in easily assessing the risk of NIs and prognosis among hospitalized patients with cirrhosis.

Bridging the critically ill patient with acute to chronic liver failure to liver transplantation

Liver transplantation (LT) has emerged as an effective therapy for severe forms of acute-on-chronic liver failure (ACLF), an entity characterized by the development of multiorgan failure and high short-term mortality. The aim of critical care management of ACLF patients is to rapidly treat precipitating events and aggressively support failing organs to ensure that patients may successfully undergo LT or, less frequently, recover. Malnutrition and sarcopenia are frequently present, adversely impacting the prognosis of these patients. Management of critical care patients with ACLF is complex and requires the participation of different specialties. Once the patient is stabilized, a rapid evaluation for salvage LT should be performed because the time window for LT is often narrow. The development of sepsis and prolonged organ support may preclude LT or diminish its chances of success. The current review describes strategies to bridge severe ACLF patients to LT, highlights the minimal evaluation required for listing and the currently suggested contraindications to proceed with LT, and addresses different aspects of management during the perioperative and early posttransplant period.

Liver transplantation for acute liver failure and acute-on-chronic liver failure

Acute liver failure (ALF) and acute-on-chronic liver (ACLF) are distinct phenotypes of liver failure and, thus, need to be compared and contrasted for appropriate management. There has been a significant improvement in the outcomes of these patients undergoing liver transplantation (LT). Survival post-LT for ALF and ACLF ranges between 90% and 95% and 80% and 90% at 1 year, futility criteria have been described in both ALF and ACLF where organ failures define survival. Plasma exchange and continuous renal replacement therapy may serve as bridging therapies. Identifying the futility of LT is as necessary as the utility of LT in patients with ALF and ACLF. The role of regenerative therapies such as granulocyte colony-stimulating factors in ACLF and hepatocyte and xenotransplantation in both conditions remains uncertain. Measures to increase the donor pool through increasing deceased donor transplants in Asian countries, living donations in Western countries, auxiliary liver transplants, and ABO-incompatible liver transplants are necessary to improve the survival of these patients. In this review, we discuss the similarities and differences in clinical characteristics and the timing and outcomes of LT for ALF and ACLF, briefly highlighting the role of bridging therapies and providing an overview of recent advances in the management of ALF and ACLF.

Improvement in Survival After Transplantation for Critically Ill Patients With Cirrhosis in the United States

INTRODUCTION

There is considerable debate over the indication of liver transplantation (LT) for critically ill patients with cirrhosis, in part due to their potentially poor post-LT prognosis. We analyzed the epidemiology and outcome of LT for critically ill patients with cirrhosis over 4 time periods of 4 years.

METHODS

We included adult patients who underwent liver transplant alone between 2005 and 2020 using the United Network for Organ Sharing registry database. We defined critically ill patients with cirrhosis as being in the intensive care unit with 1 or more of the following characteristics at the time of LT: (i) grade III/IV hepatic encephalopathy, (ii) mechanical ventilation, (iii) dialysis, and (iv) vasopressors.

RESULTS

A total of 85,594 LT recipients were included, 5,827 (6.8%) of whom were classified as being critically ill with cirrhosis at the time of LT. The number and percentage of critically ill LT recipients with cirrhosis increased over the study period: 819 (4.3%) in 2005-2008 vs 2,067 (7.9%) in 2017-2020, P < 0.001. There was a 17% absolute increase in 1-year survival after LT: 72.5% in 2005-2008 vs 89.5% in 2017-2020, P < 0.001. The 1-year post-LT survival gap between critically ill and noncritically ill patients with cirrhosis narrowed over the study period: 16.7 percentage points in 2005-2008 vs 4.6 percentage points in 2017-2020. The year of LT was independently associated with lower 1-year post-LT mortality (hazard ratio 0.92, 95% confidence interval 0.91-0.93, P < 0.001).

DISCUSSION

The absolute number and relative percentage of LT recipients who were critically ill increased over time, as did 1-year post-LT survival. Meanwhile, the gap in survival between this group of patients and noncritically ill patients with cirrhosis decreased but persisted. Cautious access to selected LT candidates who are critically ill may be warranted, provided the gap in survival with noncritically ill patients remains as small as possible.

Liver transplantation for acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) occurs in the context of advanced liver disease and is associated with hepatic and extrahepatic organ failure, eventually leading to a major risk of short-term mortality. To date, there are very few effective therapeutic options for ACLF. In many cases, liver transplantation is the only life-saving treatment that has acceptable outcomes in carefully selected recipients. This Review addresses key aspects of the use of liver transplantation for patients with ACLF, providing an in-depth discussion of existing evidence regarding candidate selection, the optimal window for transplantation, potential prioritisation of liver grafts for this indication, and the global management of ACLF to bridge patients to liver transplantation.

Serious Illness Communication in Cirrhosis Care: Tools to Improve Illness Understanding, Prognostic Understanding, and Care Planning

Patients with cirrhosis frequently experience an unpredictable illness trajectory, with frequent hospitalizations and complications. Along with the uncertain nature of the disease, the possibility of a lifesaving and curative transplant often makes prognostic discussions and future care decisions challenging. Serious illness communication (SIC) refers to supportive communication whereby clinicians assess patients' illness understanding, share prognostic information according to patients' preferences, explore patients' goals, and make recommendations for care that align with these goals. SIC includes 3 key components: (1) illness understanding; (2) prognostic understanding; and (3) care planning. In this piece, we explore current barriers to early implementation of SIC in cirrhosis care and share possible solutions, including adopting a multidisciplinary approach, delivering culturally competent care, and training clinicians in SIC core skills. By use of a case example, we aim to demonstrate SIC in action and to provide clinicians with tools and skills that can be used in practice.

The liver in sickle cell disease

Liver involvement in SCD patients is frequent but often misdiagnosed or underestimated, except in case of advanced liver diseases. Because of so far poorly recognized forms of chronic SCD-related vascular injury that can silently evolved towards end stages or facilitate ACLF, any persisting liver function tests abnormalities should be carefully investigated, following the above proposed algorithm. Work up and management must be considered multidisciplinary in relationship with a Hepatologist. Early SCD hepatopathy should prompt revision of SCD management to prevent further liver injury and decompensation, discussing transfusion exchanges and hydro urea when not yet initiated, and control for any cofactor of liver injury. The role of HSCT in early SCD hepatopathies also deserves evaluation. In advanced SCD hepatopathies, liver transplantation, which has been rarely performed so far, is the only therapeutic option associated with improved survival. It should definitely be discussed- either electively in case of decompensation in SCD cirrhosis or jaundice/recurrent cholangitis in cholestatic diseases, with excellent outcome, - or emergently in case of ALF or ACLF with more mitigate results. To improve knowledge and management of SCD liver diseases, creation of national and international registries, as well as longitudinal observational cohorts are encouraged.

Predicting post-liver transplant outcomes in patients with acute-on-chronic liver failure using Expert-Augmented Machine Learning

Liver transplantation (LT) is a treatment for acute-on-chronic liver failure (ACLF), but high post-LT mortality has been reported. Existing post-LT models in ACLF have been limited. We developed an Expert-Augmented Machine Learning (EAML) model to predict post-LT outcomes. We identified ACLF patients who underwent LT in the University of California Health Data Warehouse. We applied the RuleFit machine learning (ML) algorithm to extract rules from decision trees and create intermediate models. We asked human experts to rate the rules generated by RuleFit and incorporated these ratings to generate final EAML models. We identified 1384 ACLF patients. For death at 1 year, areas under the receiver-operating characteristic curve were 0.707 (confidence interval [CI] 0.625-0.793) for EAML and 0.719 (CI 0.640-0.800) for RuleFit. For death at 90 days, areas under the receiver-operating characteristic curve were 0.678 (CI 0.581-0.776) for EAML and 0.707 (CI 0.615-0.800) for RuleFit. In pairwise comparisons, both EAML and RuleFit models outperformed cross-sectional models. Significant discrepancies between experts and ML occurred in rankings of biomarkers used in clinical practice. EAML may serve as a method for ML-guided hypothesis generation in further ACLF research.

Review article: Emerging and current management of acute-on-chronic liver failure

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a clinically and pathophysiologically distinct condition from acutely decompensated cirrhosis and is characterised by systemic inflammation, extrahepatic organ failure, and high short-term mortality.

AIMS

To provide a narrative review of the diagnostic criteria, prognosis, epidemiology, and general management principles of ACLF. Four specific interventions that are explored in detail are intravenous albumin, extracorporeal liver assist devices, granulocyte-colony stimulating factor, and liver transplantation.

METHODS

We searched PubMed and Cochrane databases for articles published up to July 2023.

RESULTS

Approximately 35% of hospital inpatients with decompensated cirrhosis have ACLF. There is significant heterogeneity in the criteria used to diagnose ACLF; different definitions identify different phenotypes with varying mortality. Criteria established by the European Association for the Study of the Liver were developed in prospective patient cohorts and are, to-date, the most well validated internationally. Systemic haemodynamic instability, renal dysfunction, coagulopathy, neurological dysfunction, and respiratory failure are key considerations when managing ACLF in the intensive care unit. Apart from liver transplantation, there are no accepted evidence-based treatments for ACLF, but several different approaches are under investigation.

CONCLUSION

The recognition of ACLF as a distinct entity from acutely decompensated cirrhosis has allowed for better patient stratification in clinical settings, facilitating earlier engagement with the intensive care unit and liver transplantation teams. Research priorities over the next decade should focus on exploring novel treatment strategies with a particular focus on which, when, and how patients with ACLF should be treated.

Intensive care management of acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a clinical syndrome defined by an acute deterioration of the liver function associated with extrahepatic organ failures requiring intensive care support and associated with a high short-term mortality. ACLF has emerged as a major cause of mortality in patients with cirrhosis and chronic liver disease. ACLF has a unique pathophysiology in which systemic inflammation plays a key role; this provides the basis of novel therapies, several of which are now in clinical trials. Intensive care unit (ICU) therapy parallels that applied in the general ICU population in some organ failures but has peculiar differential characteristics in others. Critical care management strategies and the option of liver transplantation (LT) should be balanced with futility considerations in those with a poor prognosis. Nowadays, LT is the only life-saving treatment that can radically improve the long-term prognosis of patients with ACLF. This narrative review will provide insights on the current understanding of ACLF with emphasis on intensive care management.