Advanced non-alcoholic steatohepatitis cirrhosis: A high-risk population for pre-liver transplant portal vein thrombosis

Metabolic dysfunction-associated steatotic liver disease related cirrhosis and incidence of portal vein thrombosis

BACKGROUND

There is heterogeneous data on whether metabolic-associated steatohepatitis is an independent risk factor for portal vein thrombosis (PVT). We aim to compare the incidence of PVT in patients with cirrhosis with and without metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

This is a single-center retrospective study of patients with cirrhosis seen between 1 January 2016 and 31 January 2021. Patients with a history of hepatocellular cancer, liver transplant, Budd-Chiari syndrome, and intra-abdominal malignancies were excluded. Patients with cirrhosis were followed from their first hepatology visit for 180 days to determine the incidence of PVT. Cox proportional hazard regression was used to determine the relationship between MASLD with PVT.

RESULTS

We analyzed data from 2785 patients with cirrhosis who met inclusion and exclusion criteria [mean age: 61.0 ± 12.3 years, 44.3% female, 63.8% Whites and mean model for end-stage liver disease-sodium (MELD-Na) score: 11.7 ± 6.1]. MASLD was present in 21.7% of patients. A total of 89 patients developed PVT during the follow-up, which was fewer in patients with MASLD [2.0% vs. 3.5%, P  = 0.04, unadjusted heart rate (HR): 0.60, 95% confidence interval (CI): 0.27-0.96, P  = 0.04]. After adjusting for the demographics, MASLD-related comorbid conditions and MELD-Na score, MASLD was associated with a lower incidence of PVT as compared to non-MASLD cirrhosis (HR: 0.44, 95% CI: 0.21-0.92, P  = 0.03). After adjusting for the indicators of Child-Pugh Turcotte score, the risk of PVT in patients with MASLD compared to non-MASLD was not statistically significant (HR: 0.50, 95% CI: 0.22-1.13, P  = 0.096).

CONCLUSION

PVT incidence was lower in patients with MASLD cirrhosis as compared to non-MASLD cirrhosis. However, the difference was not significantly different after adjusting for liver decompensation.

Management of Nonmalignant Portal Vein Thrombosis in Cirrhosis

Nonmalignant portal vein thrombosis (PVT) is a common complication of cirrhosis especially at the stage of decompensations. The diagnosis of PVT in cirrhosis is often incidental and it may be detected during routine semestral abdominal ultrasound with Doppler during screening for hepatocellular carcinoma or during hospitalization for decompensated cirrhosis. After detection of PVT on abdominal ultrasound, it is important to evaluate patients with cross-sectional imaging to determine the age of thrombus, whether acute or chronic, the extent and degree of luminal occlusion of the portal vein, and to rule out hepatocellular carcinoma or other underlying malignancy. Factors influencing management include the degree and extent of luminal occlusion of PVT, potential listing for liver transplantation, and portal hypertension (PHT) complications such as variceal hemorrhage and refractory ascites, severity of thrombocytopenia, and other comorbidities including chronic kidney disease. Anticoagulation is the most common therapeutic option and it is specially indicated in patients who are candidates for liver transplantation. Interventional procedures including transjugular intrahepatic portosystemic shunt (TIPS) placement and mechanical thrombectomy may be used on a case-by-case basis in patients with contraindications or adverse events related to anticoagulation, who develop worsening PVT while on anticoagulant therapy, or have chronic PVT and PHT complications that are not manageable medically or endoscopically.

Prevalence of portal vein thrombosis in non-alcoholic fatty liver disease: a meta-analysis of observational studies

Portal vein thrombosis (PVT) is a common complication of cirrhosis as a result of portal hypertension and modification in the hemostatic balance. Accumulating evidence now suggests that patients with non-alcoholic fatty liver disease (NAFLD), especially those with advanced forms, have an increased risk of PVT. Hence, we performed a meta-analysis of observational studies to estimate the overall prevalence of PVT in patients with NAFLD and its advanced forms compared with patients with advanced liver diseases from other etiologies. We systematically searched PubMed, Scopus and Web of Science databases from the inception date to December 30th 2022, using predefined keywords, to identify observational studies. Meta-analysis was performed using random-effects modeling. We included five observational studies for a total of 225,571 patients. Of these, 26,840 (11.9%) patients had NAFLD, whereas the PVT prevalence was 8.5% (n = 2,280). When compared with patients with advanced liver diseases from other etiologies, patients with NAFLD and its advanced forms had a higher risk of prevalent PVT (OR 1.34, 100% CI 1.07-1.67 p < 0,01). The between-study heterogeneity was substantial (I2 = 88%). This meta-analysis suggests that compared with patients with advanced liver diseases from other etiologies, patient with NAFLD and its advanced forms had a higher risk of prevalent PVT. Further research is required to understand the complex link between NAFLD/NASH and PVT development.

The Yin and the Yang of Hemostasis in End-Stage Liver Disease

Patients with end-stage liver disease (ESLD) undergoing liver transplantation (LT) are prone to thromboses both while on the waiting list and in the perioperative period. This hypercoagulability is associated with significant endothelial dysfunction (ED) due to nitric oxide dysregulation. ED and increased thrombin generation are the main factors responsible for this hypercoagulability. Sepsis alone can significantly alter a patient's coagulation profile. In combination with ESLD, however, sepsis or septic shock are responsible for very complex changes. This makes both the assessment and management of coagulation in septic patients with ESLD very challenging. Viscoelastic testing (VET) is the preferred method of coagulation management in patients with cirrhosis because, as with standard laboratory testing, VET can assess the entire coagulation system including the interaction between both pro- and anticoagulants and platelets.

Late-stage presentation with decompensated cirrhosis is alarmingly common but successful etiologic therapy allows for favorable clinical outcomes

INTRODUCTION

Liver cirrhosis accounts for considerable morbidity and mortality worldwide and late presentation limits therapeutic options. We aimed to assess characteristics of patients with liver cirrhosis at the time of first presentation and during their clinical course.

METHODS

Patients with cirrhosis as evident by presence of varices at endoscopy, liver stiffness ≥15kPa at elastography, or ascites requiring paracentesis between Q1/2015-Q2/2020 were retrospectively included. Clinical, laboratory, and imaging data were collected from medical records at presentation and last follow-up.

RESULTS

476 patients were included (alcohol-related liver disease, ALD: 211, 44.3%; viral hepatitis: 163, 34.2%). Of these, 106 patients (22.3%) and 160 patients (33.6%) presented already with Child-Pugh C and MELD >15, respectively, and decompensation events were registered in 50% (238 patients) at baseline, and even in 75.4% of ALD patients. During a median follow-up of 11.0 (IQR 4-24) months, 116 patients died. Two-year survival was worse for patients with ALD than for viral hepatitis (71.1% vs. 90.2%, log rank p<0.001). We observed the highest percentage of portal-vein thrombosis (30.0%), hepatocellular carcinoma (15.0%), and death (45.0%) in the MAFLD group (n = 20). Patients cured from hepatitis C showed significant improvements in platelet count (147 to 169 G/L, p<0.001) and liver stiffness (26.2 to 17.7 kPa, p<0.001), while ALD patients improved in Child-Pugh score (8.6 to 7.6, p<0.001) during follow-up. With increasing Child Pugh score and MELD, we found increasing serum concentrations of CRP (p<0.001) and an inverse correlation with serum HDL (Spearman's ρ = -0.573 and -0.529, respectively, p<0.001).

CONCLUSION

Half of the patients with cirrhosis had decompensated cirrhosis at presentation. This calls for increased awareness and strategies for earlier diagnosis of chronic liver disease and cirrhosis.

Austrian consensus on the diagnosis and management of portal hypertension in advanced chronic liver disease (Billroth IV)

The Billroth IV consensus was developed during a consensus meeting of the Austrian Society of Gastroenterology and Hepatology (ÖGGH) and the Austrian Society of Interventional Radiology (ÖGIR) held on the 26th of November 2022 in Vienna.Based on international recommendations and considering recent landmark studies, the Billroth IV consensus provides guidance regarding the diagnosis and management of portal hypertension in advanced chronic liver disease.

Incident portal vein thrombosis in liver transplant recipients in New Zealand: Predictors of risk and validation of portal vein thrombosis risk index calculator

The risk of spontaneous portal vein thrombosis (PVT) is increased in patients on the waiting list for liver transplantation and increases perioperative risks. A predictive PVT risk-index (PVT-RI) calculator has been proposed to determine the risk of incident PVT. We performed a retrospective analysis on adult liver transplant recipients at the NZ Liver Transplant Unit between January 1998 and February 2020. Variables reviewed included age at listing and transplantation, wait time from listing to transplant, indication for listing, gender, ethnicity, etiology of liver disease, listing MELD score, hepatocellular carcinoma (HCC), moderate-to-severe ascites, hepatic encephalopathy (>grade 2), transjugular intrahepatic portosystemic shunt (TIPSS), spontaneous bacterial peritonitis (SBP), and diabetes. Incident PVT was determined by imaging of patients while on the waiting list and assessment at transplantation. A total of 553 out of 706 patients met the inclusion criteria. Of those 553, 18 (3.3%) patients had incident PVT. The PVT-RI calculator was not validated in our cohort with only one of those 18 (6%) patients having a score of >4.6 (high risk cut-off score). Longer waiting time for transplant and listing for liver failure rather than HCC were independent predictors of the risk of incident PVT. There was no statistically significant difference in the incidence of PVT in viral vs. non-viral and cholestatic vs. non-cholestatic etiology of chronic liver disease. Patients with longer waiting times on the transplant waiting list should be monitored regularly for PVT.

Pulmonary embolism risk in hospitalized patients with nonalcoholic fatty liver disease: A case-control study

Abundant research has associated nonalcoholic fatty liver disease (NAFLD) with atherosclerosis, but very few reports have evaluated the association between NAFLD and venous thromboembolism. We aimed to investigate the association between NAFLD and pulmonary embolism (PE) in hospitalized patients. In this retrospective case-control study, we included consecutive patients from 2 university-affiliated hospitals who were referred for CT pulmonary angiograms for a suspected PE. Patients with a history of excessive alcohol consumption, chronic liver diseases or cirrhosis were excluded. The imaging studies of the entire cohort were reviewed by 2 expert radiologists who confirmed the diagnosis of PE and examined the liver to detect and grade hepatic steatosis. Accordingly, patients were categorized into NAFLD patients and non-NAFLD controls. Patient demographics, medical history, hospitalization details as well as patients' outcomes were documented. Multivariate analysis was performed to identify predictors for developing PE and hazard ratios with corresponding 95% confidence intervals were estimated. A total of 377 patients (101 with NAFLD and 276 controls) were included. NAFLD patients had significantly higher BMI values (33.16 ± 6.78 vs 26.81 ± 5.6; P < .001) and prevalence of diabetes (41 (40%) vs 85 (30.8%); P = .03). The prevalence of PE was significantly higher in the NAFLD group (80 (79.2%) vs 147 (53.3%), P < .001). In a multivariate analysis, older age, recent surgery or trauma, active malignancy, smoking, and NAFLD (HR ratio = 4.339, P < .0001 and 95% CI = 2.196-8.572) were independently associated with PE development. Patients with NAFLD were associated with an increased risk of developing PE independent of other classical risk factors for PE.

Management of Patients With Non-alcoholic Steatohepatitis Undergoing Liver Transplantation: Considerations for the Anesthesiologist

Non-alcoholic fatty liver disease (NAFLD) currently affects more than 25% of the world population and is rising. NAFLD can progress to non-alcoholic steatohepatitis that is associated with hepatic inflammation and fibrosis and can result in cirrhosis with subsequent liver failure. Non-alcoholic steatohepatitis (NASH) has now emerged as one of the leading etiologies for a liver transplant among adults in the United States. Given the rising incidence of liver transplants in patients with NASH-related cirrhosis, it is essential for anesthesiologists to be familiar with this condition as well as with NASH-related comorbidities and perioperative complications. Not only is NASH linked to metabolic syndrome, but it also is independently associated with cardiovascular disease, renal and thyroid dysfunction, obstructive sleep apnea (OSA), and a hypercoagulable state. The association with these conditions can affect the perioperative outcome of these patients, particularly because of increased mortality from major adverse cardiovascular events and sepsis. In order to decrease the perioperative morbidity and mortality of patients with NASH undergoing a liver transplant, a multidisciplinary approach to their perioperative management is essential, along with careful preoperative evaluation and aggressive intraoperative and postoperative monitoring. The focus of this review article is to provide a comprehensive overview of challenges associated with liver transplants in patients with NASH and to provide suggestions for appropriate patient selection and perioperative management.

Pre-transplant portal vein thrombosis in non-alcoholic fatty liver disease patients-pathogenesis, risk factors, and implications on management

Along with the worldwide increase in obesity and metabolic syndrome, non-alcoholic fatty liver disease (NAFLD) and its more severe subset, non-alcoholic steatohepatitis (NASH), are on path to become the leading cause of liver transplantation in the United States. NAFLD, as well as obesity, create an inflammatory milieu via the release of adipocytokines. In turn, the inflammatory environment can trigger an increase in prothrombotic factors. Independent of inflammation, the severity of NASH is associated with a graded increase in hypercoagulability such as an increase in factor VIII, increase in plasminogen activator inhibitor-1, and decrease in protein C. Ultimately, this environment creates an increase in thrombotic risk, leading to higher rates of pre-transplant portal vein thrombosis (PVT) in patients with NASH cirrhosis vesus other causes of cirrhosis. Many studies have shown worse outcomes in liver transplant recipients with PVT as it complicates anastomotic reconstruction which can negatively affect portal blood supply needed for adequate liver functioning. Management and treatment of PVT is not standardized, but from a pharmacologic standpoint, multiple classes of anticoagulants have shown to be successful in recanalization of the portal vein and preventing recurrence of clot with minimal bleeding complications. The increasing prevalence of NASH cirrhosis and subsequent increase in PVT require further research for improved outcomes.

NASHFit: A randomized controlled trial of an exercise training program to reduce clotting risk in patients with NASH

BACKGROUND AND AIMS

NASH is a common disease associated with increased rates of thromboembolism (TE). Although exercise training can lessen thrombotic risk in patients with vascular disease, whether similar findings are observed in patients with NASH is open for study.

APPROACH AND RESULTS

We conducted a 20-week randomized controlled clinical trial involving patients with biopsy-confirmed NASH. Patients were randomly assigned (2:1 ratio) to receive either an exercise training program or standard clinical care. The primary endpoint was change in plasminogen activator inhibitor 1 (PAI-1) level, an established thrombotic biomarker. Twenty-eight patients were randomly assigned (18 exercise training and 10 standard clinical care). PAI-1 level was significantly decreased by exercise training when compared to standard clinical care (-40 ± 100 vs. +70 ± 63 ng/ml; p = 0.02). Exercise training decreased MRI proton density fat fraction (MRI-PDFF; -4.7 ± 5.6 vs. 1.2 ± 2.8% absolute liver fat; p = 0.01); 40% of exercise subjects had a ≥30% relative reduction in MRI-PDFF (histological response threshold) compared to 13% for standard of care (p < 0.01). Exercise training improved fitness (VO₂ peak, +3.0 ± 5.6 vs. -1.8 ± 5.1 ml/kg/min; p = 0.05) in comparison to standard clinical care.

CONCLUSIONS

This clinical trial showed that, independent of weight loss or dietary change, exercise training resulted in a significantly greater decrease in thrombotic risk than standard clinical care in patients with NASH, in parallel with MRI-PDFF reduction and improvement in fitness. Future studies are required to determine whether exercise training can directly impact patient outcomes and lower rates of TE.

Coagulation and Endothelial Dysfunction Associated with NAFLD: Current Status and Therapeutic Implications

Non-alcoholic fatty liver disease (NAFLD) is closely related to insulin resistance, type 2 diabetes mellitus and obesity. It is considered a multisystem disease and there is a strong association with cardiovascular disease and arterial hypertension, which interfere with changes in the coagulation system. Coagulation disorders are common in patients with hepatic impairment and are dependent on the degree of liver damage. Through a review of the literature, we consider and discuss possible disorders in the coagulation cascade and fibrinolysis, endothelial dysfunction and platelet abnormalities in patients with NAFLD.

Direct oral anticoagulant administration in cirrhotic patients with portal vein thrombosis: What is the evidence?

In recent years, the traditional concept that cirrhosis-related coagulopathy is an acquired bleeding disorder has evolved. Currently, it is known that in cirrhotic patients, the hemostatic system is rebalanced, which involves coagulation factors, fibrinolysis and platelets. These alterations disrupt homeostasis, skewing it toward a procoagulant state, which can lead to thromboembolic manifestations, especially when hemodynamic and endothelial factors co-occur, such as in the portal vein system in cirrhosis. Portal vein thrombosis is a common complication of advanced liver cirrhosis that negatively affects the course of liver disease, prognosis of cirrhotic patients and success of liver transplantation. It is still debated whether portal vein thrombosis is the cause or the consequence of worsening liver function. Anticoagulant therapy is the mainstay treatment for acute symptomatic portal vein thrombosis. In chronic portal vein thrombosis, the role of anticoagulant therapy is still unclear. Traditional anticoagulants, vitamin K antagonists and low-molecular-weight heparin are standard-of-care treatments for portal vein thrombosis. In the last ten years, direct oral anticoagulants have been approved for the prophylaxis and treatment of many thromboembolic-related diseases, but evidence on their use in cirrhotic patients is very limited. The aim of this review was to summarize the evidence about the safety and effectiveness of direct oral anticoagulants for treating portal vein thrombosis in cirrhotic patients.

Plasminogen activator inhibitor is significantly elevated in liver transplant recipients with decompensated NASH cirrhosis

Background

Non-alcoholic fatty liver disease is a prohaemostatic state with abnormal primary, secondary and tertiary haemostasis. Plasminogen activator inhibitor (PAI)-1 is the best-established marker for prohaemostasis in non-alcoholic fatty liver disease. While epidemiological studies demonstrate decompensated non-alcoholic steatohepatitis (NASH) cirrhosis patients have increased rates of venous thromboembolism, including portal vein thrombosis, mechanistic studies have focused exclusively on patients without or with compensated cirrhosis. We aimed to characterizecharacterise PAI-1 levels in decompensated NASH cirrhosis.

Methods

PAI-1 level was measured in consecutive adult liver transplant recipients immediately prior to liver transplantation. Multivariable models were constructed using linear regression to assess factors related to PAI-1 level.

Results

Forty-six subjects with mean age 57 (IQR 53–62) years and Model for Endstage Liver Disease (MELD) score of 34 (IQR 30–40) were enrolled. Baseline characteristics were similar between NASH (n=10) and non-NASH (n=36) subjects except for rates of diabetes and hyperlipidaemia. Mean PAI-1 level was greater in NASH (53.9, 95% CI 33.3 to 74.5 mg/mL) when compared with non-NASH (36.1, 95% CI 28.7 to 43.5), p=0.040. NASH remained independently predictive of PAI-1 level prior to transplant on adjusted multivariable modelling (β 40.13, 95% CI 14.41 to 65.86, p=0.003). Conclusions: PAI-1 level is significantly elevated in decompensated NASH cirrhosis independent of other pro-haemostatic factors. This may explain the greater rates of venous thromboembolism in decompensated NASH cirrhosis. Future study focusing on prevention of venous thromboembolism in this population is paramount to improve patient-oriented outcomes given the high morbidity and mortality of venous thromboembolism and the significant impact it has on transplant candidacy.

Portal vein thrombosis: A concise review (Review)

Portal vein thrombosis (PVT) is a frequent complication in cirrhotic patients, but it may also exist as a basic vascular condition even without any liver damage. Local and systemic factors play a significant role in the pathogenesis of PVT; yet, in practice, more than one factor may be identified. PVT can be considered a result of liver fibrosis and hepatic insufficiency. The JAK2 mutation has been accepted as a factor producing PVT. In general, the anticoagulants are recommended but this therapy should be used carefully in treating patients that associate coagulopathy or thrombocytopenia and esophageal varices. Acute PVT without bowel infarction has a good prognosis. In liver cirrhosis, the mortality due to hemorrhage is higher than in chronic PVT. Therefore, for the patients with PVT, the survival rate is decreased by 55% in two years, due to hepatic insufficiency. Regarding the treatment, LMWH (low molecular weight heparine) is the most utilized in patients with cirrhosis, non-malignancies, infections, or those who are awaiting a liver transplant. DOACs (direct-acting oral anticoagulants) may be used in the rest of the medical conditions, being safe and equal to LMWH.

Nontumoral Portal Vein Thrombosis: A Challenging Consequence of Liver Cirrhosis

Nontumoral portal vein thrombosis (PVT) is an increasingly recognized complication in patients with cirrhosis. Substantial evidence shows that portal flow stasis, complex thrombophilic disorders, and exogenous factors leading to endothelial dysfunction have emerged as key factors in the pathogenesis of PVT. The contribution of PVT to hepatic decompensation and mortality in cirrhosis is debatable; however, the presence of an advanced PVT increases operative complexity and decreases survival after transplantation. The therapeutic decision for PVT is often determined by the duration and extent of thrombosis, the presence of symptoms, and liver transplant eligibility. Evidence from several cohorts has demonstrated that anticoagulation treatment with vitamin K antagonist or low molecular weight heparin can achieve recanalization of the portal vein, which is associated with a reduction in portal hypertension-related events and improved survival in cirrhotic patients with PVT. Consequently, interest in direct oral anticoagulants for PVT is increasing, but clinical data in cirrhosis are limited. Although the most feared consequence of anticoagulation is bleeding, most studies indicate that anticoagulation therapy for PVT in cirrhosis appears relatively safe. Interestingly, the data showed that transjugular intrahepatic portosystemic shunt represents an effective adjunctive therapy for PVT in cirrhotic patients with symptomatic portal hypertension if anticoagulation is ineffective. Insufficient evidence regarding the optimal timing, modality, and duration of therapy makes nontumoral PVT a challenging consequence of cirrhosis. In this review, we summarize the current literature and provide a potential algorithm for the management of PVT in patients with cirrhosis.

Nonalcoholic Fatty Liver Disease-Evidence for a Thrombophilic State?

Nonalcoholic fatty liver disease is the leading cause of liver disease worldwide. It has expansive extrahepatic morbidity and mortality including increased rates of both cardiovascular disease and venous thromboembolism. Derangements in primary, secondary and tertiary hemostasis are found in nonalcoholic fatty liver disease independent of those ascribed to end-stage liver disease. The abnormalities across all stages of hemostasis explain the increased rates of clinically relevant thrombotic events, including pulmonary embolism, deep vein thrombosis and portal vein thrombosis, which on an epidemiologic basis appears to be independent of obesity and other traditional venous thromboembolic risk factors. However, given the complex interaction between obesity, body composition and nonalcoholic fatty liver disease and the potential for exercise to benefit all three, more research is needed to further define the role of each in contributing to the prohemostatic state of nonalcoholic fatty liver disease in order to improve patient oriented outcomes.

New Insights into the Pathogenesis, Risk Factors, and Treatment of Portal Vein Thrombosis in Patients with Cirrhosis

Portal vein thrombosis (PVT) is a frequent event in patients with cirrhosis regardless of etiology. Notwithstanding the commonality of the problem, the pathophysiology and risk factors for PVT in cirrhosis are largely unknown. The clinical impact of PVT in the natural history of cirrhosis is unclear, indications for PVT treatment are not well defined, and treatment recommendations are based on experts' opinion and consensus only. Therefore, this review aims to summarize current knowledge of mechanisms and risk factors for PVT development and assess the current evidence of PVT management, with a special focus on strategies of anticoagulation and transjugular intrahepatic portosystemic shunt placement.

Nonalcoholic steatohepatitis Fitness Intervention in Thrombosis (NASHFit): Study protocol for a randomized controlled trial of a supervised aerobic exercise program to reduce elevated clotting risk in patients with NASH

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide affecting upwards of one third the global population. For reasons not fully understood, individuals with NAFLD and its more severe variant, nonalcoholic steatohepatitis (NASH), are at increased risk for venous thromboembolism which significantly increases morbidity and mortality. Lifestyle changes centering around exercise training are the mainstay of treatment for NAFLD/NASH. While exercise training can lessen venous thromboembolic risk in healthy persons and those with cardiovascular disease, whether or not this benefit is seen in patients with NAFLD/NASH remains unknown. In order to better understand how exercise training impacts thrombosis risk in NAFLD, we present the design of a thirty-two week randomized controlled clinical trial of 42 sedentary subjects age 18-69 with biopsy proven NASH. The main aim is to determine the impact of an aerobic exercise training program on the abnormal hemostatic system unique to NAFLD/NASH. The main outcome is change in plasminogen activator inhibitor one level, an established marker for venous thromboembolism. Secondary outcomes include body composition, cardiorespiratory fitness, control of comorbid metabolic conditions (e.g., obesity, hypertension, hyperlipidemia, diabetes), dietary composition, health related quality of life, liver enzymes and histology, NAFLD/NASH disease activity (e.g., biomarkers, clinical decision aids), microbiome, other markers of hemostasis, and PNPLA3 gene expression. The study represents the first clinical trial of an exercise training program to reduce elevated clotting risk in subjects with NAFLD/NASH.

Direct Oral Anticoagulants in Patients with Liver Disease in the Era of Non-Alcoholic Fatty Liver Disease Global Epidemic: A Narrative Review

Atrial fibrillation (AF) and venous thromboembolism (VTE) are highly prevalent and relevant healthcare issues. Direct oral anticoagulants (DOACs) are now the first-choice for anticoagulant treatment of these conditions displaying a better efficacy/safety profile than vitamin-K antagonists, mainly due to significantly reduced risk of major bleeding, especially of intracranial haemorrhage. Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in developed countries showing a continuously growing prevalence. Nonalcoholic steatohepatitis (NASH), its evolutive form, will be the leading cause for liver transplantation by 2020. NAFLD is independently associated with an increased risk of abnormalities of cardiac structure and function, including cardiac rhythm disorders (mainly AF). Moreover, data suggest an increased risk of unprovoked VTE associated with NAFLD/NASH. Therefore, a growing number of patients with chronic liver disease (CLD) will be candidate for anticoagulant therapy in the near future. Cirrhosis of any etiology is characterized by an unstable thrombosis/bleeding haemostatic balance, making anticoagulant therapy particularly challenging in this condition. Given that patients with significant active liver disease and cirrhosis were excluded from all pivotal randomized controlled trials on DOACs, this comprehensive review aims at critically discussing real-world evidence, including the latest population studies, regarding the use of DOACs in patients with CLD/cirrhosis.

Metabolic syndrome and hepatic surgery

In Europe, the prevalence of metabolic syndrome (MS) has reached the endemic rate of 25%. Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of MS. Its definition is histological, bringing together the different lesions associated with hepatic steatosis (fat deposits on more than 5% of hepatocytes) without alcohol consumption and following exclusion of other causes. MS and NAFLD are implicated in the carcinogenesis of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). At present, HCC and ICC involving MS represent 15-20% and 20-30% respectively of indications for hepatic resection in HCC and ICC. Moreover, in the industrialized nations NAFLD is tending to become the most frequent indication for liver transplantation. MS patients combine the operative risk associated with their general condition and comorbidities and the risk associated with the presence and/or severity of NAFLD. Following hepatic resection in cases of HCC and ICC complicating MS, the morbidity rate ranges from 20 to 30%, and due to cardiovascular and infectious complications, post-transplantation mortality is heightened. The operative risk incurred by MS patients necessitates appropriate management including: (i) precise characterization of the subjacent liver; (ii) an accurately targeted approach privileging detection and optimization of treatment taking into account the relevant cardiovascular risk factors; (iii) a surgical strategy adapted to the histology of the underlying liver, with optimization of the volume of the remaining (postoperative) liver.

Development of a Model to Predict Portal Vein Thrombosis in Liver Transplant Candidates: The Portal Vein Thrombosis Risk Index

Portal vein thrombosis (PVT) is associated with inferior pretransplantation and posttransplantation outcomes. We aimed to create a predictive model to risk stratify transplant candidates for PVT. Data on adult transplants in the United States during the Model for End-Stage Liver Disease (MELD) era through September 2016 were reviewed. We constructed and validated a scoring system composed of routine, readily available clinical information to predict the development of incident PVT at 12 months from transplantation listing. A total of 66,568 liver transplant candidates were dichotomized into 2 groups to construct (n = 34,751) and validate (n = 31,817) a scoring system. In general, the derivation and validation cohorts were clinically similar. Although nonalcoholic steatohepatitis was a significant predictor of incident PVT (hazard ratio, 1.29; 95% confidence interval, 1.08-1.54; P < 0.001), age, MELD score, and moderate-to-severe ascites were also associated with increased risk. African American race was associated with decreased risk. A scoring system (PVT risk index [RI]) of these 5 variables had an area under the curve of 0.71 and 0.70 in both derivation and validation cohorts, respectively. By applying the low cutoff score of 2.6, incident PVT could be accurately excluded (negative predictive value 94%). Using the high cutoff score of 4.6 (positive predictive value 85%), PVT could be diagnosed with high accuracy. The PVT-RI predicts which candidates awaiting lifesaving liver transplantation will and will not develop future PVT. Although this scoring system will require prospective validation, it provides a powerful new tool for the clinician when risk stratifying cirrhosis patients prior to liver transplantation for future PVT development.

Portal vein thrombosis in cirrhosis: Why a well-known complication is still matter of debate

Portal vein thrombosis (PVT) represents a well-known complication during the natural course of liver cirrhosis (LC), ranging from asymptomatic cases to life-threating conditions related to portal hypertension and hepatic decompensation. Portal flow stasis, complex acquired hypercoagulable disorders and exogenous factors leading to endothelial dysfunction have emerged as key factors for PVT development. However, PVT occurrence remains unpredictable and many issues regarding its natural history, prognostic significance and treatment are still elusive. In particular although spontaneous resolution or disease stability occur in most cases of PVT, factors predisposing to disease progression or recurrence after spontaneous recanalization are not clarified as yet. Moreover, PVT impact on LC outcome is still debated, as PVT may represent itself a consequence of liver fibrosis and hepatic dysfunction progression. Anticoagulation and transjugular intrahepatic portosystemic shunt are considered safe and effective in this setting and are recommended in selected cases, even if the safer therapeutic option and the optimal therapy duration are still unknown. Nevertheless, their impact on mortality rates should be addressed more extensively. In this review we present the most debated questions regarding PVT, whose answers should come from prospective cohort studies and large sample-size randomized trials.

Ischaemia reperfusion injury in liver transplantation: Cellular and molecular mechanisms

Liver disease causing end organ failure is a growing cause of mortality. In most cases, the only therapy is liver transplantation. However, liver transplantation is a complex undertaking and its success is dependent on a number of factors. In particular, liver transplantation is subject to the risks of ischaemia-reperfusion injury (IRI). Liver IRI has significant effects on the function of a liver after transplantation. The cellular and molecular mechanisms governing IRI in liver transplantation are numerous. They involve multiple cells types such as liver sinusoidal endothelial cells, hepatocytes, Kupffer cells, neutrophils and platelets acting via an interconnected network of molecular pathways such as activation of toll-like receptor signalling, alterations in micro-RNA expression, production of ROS, regulation of autophagy and activation of hypoxia-inducible factors. Interestingly, the cellular and molecular events in liver IRI can be correlated with clinical risk factors for IRI in liver transplantation such as donor organ steatosis, ischaemic times, donor age, and donor and recipient coagulopathy. Thus, understanding the relationship of the clinical risk factors for liver IRI to the cellular and molecular mechanisms that govern it is critical to higher levels of success after liver transplantation. This in turn will help in the discovery of therapeutics for IRI in liver transplantation - a process that will lead to improved outcomes for patients suffering from end-stage liver disease.

Nonalcoholic Fatty Liver Disease: Epidemiology, Liver Transplantation Trends and Outcomes, and Risk of Recurrent Disease in the Graft

In parallel with the rising prevalence of metabolic syndrome globally, nonalcoholic fatty liver (NAFL) disease is the most common chronic liver disease in Western countries and nonalcoholic steatohepatitis (NASH) has become increasingly associated with hepatocellular carcinoma. Recent studies have identified NASH as the most rapidly growing indication for liver transplantation (LT). As a hepatic manifestation of the metabolic syndrome, NAFL disease can be histologically divided into NAFL and NASH. NAFL is considered a benign condition, with histological changes of hepatocyte steatosis but without evidence of hepatocellular injury or fibrosis. This is distinct from NASH, which is characterized by hepatocyte ballooning and inflammation, and which can progress to fibrosis and cirrhosis, hepatocellular carcinoma, and liver failure. As for any other end-stage liver disease, LT is a curative option for NASH after the onset of decompensated cirrhosis or hepatocellular carcinoma. Although some studies have suggested increased rates of sepsis and cardiovascular complications in the immediate postoperative period, the long-term posttransplant survival of NASH cases is similar to other indications for LT. Recurrence of NAFL following LT is common and can be challenging, although recurrence rates of NASH are lower. The persistence or progression of metabolic syndrome components after LT are likely responsible for NASH recurrence in transplanted liver. Therefore, while maintaining access to LT is important, concerted effort to address the modifiable risk factors and develop effective screening strategies to identify early stages of disease are paramount to effectively tackle this growing epidemic.

Nonalcoholic fatty liver disease is an increasing indication for liver transplantation in the Nordic countries

BACKGROUND & AIMS

Nonalcoholic fatty liver disease(NAFLD) is the second most common cause of liver transplantation in the US. Data on NAFLD as a liver transplantation indication from countries with lower prevalences of obesity are lacking. We studied the temporal trends of NAFLD as an indication for liver transplantation in the Nordic countries, and compared outcomes for patients with NAFLD to patients with other indications for liver transplantation.

METHOD

Population-based cohort study using data from the Nordic Liver Transplant Registry on adults listed for liver transplantation between 1994 and 2015. NAFLD as the underlying indication for liver transplantation was defined as a listing diagnosis of NAFLD/nonalcoholic steatohepatitis, or cryptogenic cirrhosis with a body mass index ≥25 kg/m2 and absence of other liver diseases. Waiting time for liver transplantation, mortality and withdrawal from the transplant waiting list were registered. Survival after liver transplantation was calculated using multivariable Cox regression, adjusted for age, sex, body mass index and model for end-stage liver disease.

RESULTS

A total of 4609 patients listed for liver transplantation were included. NAFLD as the underlying indication for liver transplantation increased from 2.0% in 1994-1995 to 6.2% in 2011-2015 (P = .01) and was the second most rapidly increasing indication. NAFLD patients had higher age, model for end-stage liver disease and body mass index when listed for liver transplantation, but overall survival after liver transplantation was comparable to non--NAFLD patients (aHR 1.03, 95% CI 0.70-1.53 P = .87).

CONCLUSION

NAFLD is an increasing indication for liver transplantation in the Nordic countries. Despite more advanced liver disease, NAFLD patients have a comparable survival to other patients listed for liver transplantation.

Nonalcoholic fatty liver disease and liver transplantation - Where do we stand?

Nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NAFLD/NASH) is a challenging and multisystem disease that has a high socioeconomic impact. NAFLD/NASH is a main cause of macrovesicular steatosis and has multiple impacts on liver transplantation (LT), on patients on the waiting list for transplant, on post-transplant setting as well as on organ donors. Current data indicate new trends in the area of chronic liver disease. Due to the increased incidence of metabolic syndrome (MetS) and its components, NASH cirrhosis and hepatocellular carcinoma caused by NASH will soon become a major indication for LT. Furthermore, due to an increasing incidence of MetS and, consequently, NAFLD, there will be more steatotic donor livers and less high quality organs available for LT, in addition to a lack of available liver allografts. Patients who have NASH and are candidates for LT have multiple comorbidities and are unique LT candidates. Finally, we discuss long-term grafts and patient survival after LT, the recurrence of NASH and NASH appearing de novo after transplantation. In addition, we suggest topics and areas that require more research for improving the health care of this increasing patient population.

Increased risk of venous thromboembolism in hospitalized patients with cirrhosis due to non-alcoholic steatohepatitis

Objective

Patients with cirrhosis are at increased risk for venous thromboembolism (VTE) and portal vein thrombosis (PVT). Cirrhosis due to non-alcoholic steatohepatitis (NASH) appears to be particularly prothrombotic. We investigated hospitalized patients with NASH cirrhosis to determine if they are at increased risk for VTE.

Methods

Data on adult hospitalized patients with cirrhosis and VTE (deep vein thrombosis and/or pulmonary embolism) between November 1, 2010 and December 31, 2015 were obtained. Cases with VTE were matched by age, gender, and model for end stage liver disease (MELD) score to corresponding controls without VTE.

Results

Two hundred and ninety subjects (145 matched pairs) with mean age of 58.4 ± 11.8 years and MELD score of 16.0 ± 7.2 were included. Baseline characteristics were similar between cases and controls. Independent adjusted risk factors for VTE included NASH (OR: 2.46, 95% CI: 1.07–5.65, p = 0.034), prior VTE (OR: 7.12, 95% CI: 1.99–25.5, p = 0.003), and presence of PVT (OR: 2.18, 95% CI: 1.03–4.58, p = 0.041). Thrombocytopenia was associated with decreased risk (OR: 0.49, 95% CI: 0.26–0.95, p = 0.035).

Conclusions

NASH is an independent risk factor for VTE among cirrhosis patients and provides further evidence that NASH is a hypercoagulable state. While all hospitalized patients with cirrhosis at risk for VTE should be considered for medical thromboprophylaxis, those with NASH cirrhosis are at particularly increased risk and therefore a high index of suspicion for VTE should be maintained even in the presence of thromboprophylaxis.

Decreased portal vein velocity is predictive of the development of portal vein thrombosis: A matched case-control study

BACKGROUND & AIMS

Portal vein thrombosis (PVT) in cirrhosis may lead to hepatic decompensation and increased mortality. We aimed to investigate if decreased portal vein (PV) velocity is associated with future PVT.

METHODS

Data on adult patients with cirrhosis and PVT between January 1, 2005 and July 30, 2015 were obtained. Cases with PVT were matched by age, gender and Model for End-stage Liver Disease (MELD) score to corresponding controls without PVT. Cox proportional hazards models, receiver operator curves and Kaplan Meier curves were constructed.

RESULTS

One hundred subjects (50 matched pairs) with mean age 53.8±13.1 y and MELD score 14.9±5.5 were included in our analysis. Sixty-four percent were male and 76% were Child-Turcotte-Pugh Class A or B. Baseline characteristics (prior to development of PVT) were similar, except for baseline PV velocity (16.9 cm/s, 95% CI 13.9-20.0 PVT vs 25.0, 95% CI 21.8-28.8 no PVT, P<.001). 30 PVT subjects had PV velocity <15 cm/s compared to five without PVT (P<.001). On adjusted multivariable analysis, PV velocity was the strongest independent risk factor predicting PVT development (HR 0.86, 95% CI 0.80-0.93). The predictive value for PVT development was greatest for flow <15 cm/s (c-statistic 0.77). PV velocity <15 cm/s had a highly significant association with future PVT (HR 6.00, 95% CI 2.20-16.40, P=<.001).

CONCLUSIONS

Decreased PV velocity is associated with increased risk of future PVT. Patients with cirrhosis and decreased PV velocity are a high-risk subgroup that warrants further investigation with prospective study.

Hepatic CD36 downregulation parallels steatosis improvement in morbidly obese undergoing bariatric surgery

BACKGROUND

The notion that hepatic expression of genes involved in lipid metabolism is altered in obese patients is relatively new and its relationship with hepatic steatosis and cardiometabolic alterations remains unclear.

OBJECTIVE

We assessed the impact of Roux-en-Y gastric bypass surgery (RYGB) on the expression profile of genes related to metabolic syndrome in liver biopsies from morbidly obese individuals using a custom-made, focused cDNA microarray, and assessed the relationship between the expression profile and hepatic steatosis regression.

MATERIALS AND METHODS

Plasma and liver samples were obtained from patients at baseline and 12 months after surgery. Samples were assayed for chemical and gene expression analyses, as appropriate. Gene expression profiles were assessed using custom-made, focused TaqMan low-density array cards.

RESULTS

RYGB-induced weight loss produced a favorable reduction in fat deposits, insulin resistance (estimated by homeostasis model assessment of insulin resistance (HOMA-IR)), and plasma and hepatic lipid levels. Compared with the baseline values, the gene expression levels of key targets of lipid metabolism were significantly altered: CD36 was significantly downregulated (-40%; P=0.001), whereas APOB (+27%; P=0.032) and SCARB1 (+37%; P=0.040) were upregulated in response to surgery-induced weight reduction. We also observed a favorable reduction in the expression of the PAI1 gene (-80%; P=0.007) and a significant increase in the expression of the PPARA (+60%; P=0.014) and PPARGC1 genes (+36%; P=0.015). Notably, the relative fold decrease in the expression of the CD36 gene was directly associated with a concomitant reduction in the cholesterol (Spearman's r=0.92; P=0.001) and phospholipid (Spearman's r=0.76; P=0.04) contents in this tissue.

CONCLUSIONS

For the first time, RYGB-induced weight loss was shown to promote a favorable downregulation of CD36 expression, which was proportional to a favorable reduction in the hepatic cholesterol and phospholipid contents in our morbidly obese subjects following surgery.