Rebalanced hemostasis in patients with liver disease: evidence and clinical consequences. Blood. 2010;116:878-885. [PMID: 20400681 DOI: 10.1182/blood-2010-02-261891]

Von Willebrand factor delays liver repair after acetaminophen-induced acute liver injury in mice

BACKGROUND & AIM

Acetaminophen (APAP)-induced acute liver failure is associated with substantial alterations in the hemostatic system. In mice, platelets accumulate in the liver after APAP overdose and appear to promote liver injury. Interestingly, patients with acute liver injury have highly elevated levels of the platelet-adhesive protein von Willebrand factor (VWF), but a mechanistic connection between VWF and progression of liver injury has not been established. We tested the hypothesis that VWF contributes directly to experimental APAP-induced acute liver injury.

METHODS

Wild-type mice and VWF-deficient (Vwf^-/-) mice were given a hepatotoxic dose of APAP (300 mg/kg, i.p.) or vehicle (saline). VWF plasma levels were measured by ELISA, and liver necrosis or hepatocyte proliferation was measured by immunohistochemistry. Platelet and VWF deposition were measured by immunofluorescence.

RESULTS

In wild-type mice, VWF plasma levels, high molecular weight (HMW) VWF multimers, and VWF activity decreased 24 h after APAP challenge. These changes coupled to robust hepatic VWF and platelet deposition, although VWF deficiency had minimal effect on peak hepatic platelet accumulation or liver injury. VWF plasma levels were elevated 48 h after APAP challenge, but with relative reductions in HMW multimers and VWF activity. Whereas hepatic platelet aggregates persisted in livers of APAP-challenged wild-type mice, platelets were nearly absent in Vwf^-/- mice 48 h after APAP challenge. The absence of platelet aggregates was linked to dramatically accelerated repair of the injured liver. Complementing observations in Vwf^-/- mice, blocking VWF or the platelet integrin α_IIbβ₃ during development of injury significantly reduced hepatic platelet aggregation and accelerated liver repair in APAP-challenged wild-type mice.

CONCLUSION

These studies are the first to suggest a mechanistic link between VWF, hepatic platelet accumulation, and liver repair. Targeting VWF might provide a novel therapeutic approach to improve repair of the APAP-injured liver.

LAY SUMMARY

Patients with acute liver injury due to acetaminophen overdose have highly elevated levels of the platelet-adhesive protein von Willebrand factor. It is not known whether von Willebrand factor plays a direct role in the progression of acute liver injury. We discovered that von Willebrand factor delays repair of the acetaminophen-injured liver in mice and that targeting von Willebrand factor, even in mice with established liver injury, accelerates liver repair.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Liver Disease and Hemostasis (Review) Part 2. Cholestatic Liver Disease and Hemostasis

The presence or development of liver disorders can significantly complicate the course of critical illness and terminal conditions. Systemic hemostatic disorders are common in Intensive Care Units patients with cholestatic liver diseases, so the study of the mechanisms of their development can contribute to the understanding of the development of multiorgan failure in critical illness.

The review discusses current data on changes in hemostatic parameters in patients with cholestatic liver diseases, proposes a mechanism for the development of such disorders, which involve interactions of phospholipids with platelet and endotheliocyte membranes. It is suggested that a trend for thrombosis in patients with cholestatic liver disease is due to increased accumulation of bile acids in the systemic circulation. Available data demonstrate that the antiphospholipid syndrome may predispose to the formation of blood clots due to alterations of phospholipid composition of membranes of platelets and vascular endothelial cells by circulating antiphospholipid antibodies. Clarifying the mechanisms contributing to changes of the blood coagulation system parameters in liver disorders will aid to development of optimal correction of hemostatic disorders in patients with chronic liver diseases.

Transfusion strategies in patients with cirrhosis

Bleeding related to portal hypertension and coagulopathy is a common complication in patients with cirrhosis. Complications and management of bleeding is a significant source of healthcare cost and utilization, as well as morbidity and mortality. Due to the scarcity of evidence surrounding transfusion strategies and hemostatic interventions in patients with cirrhosis, there has been significant debate regarding the best practice. Emerging data suggest that evidence supporting transfusion of packed red blood cells to a hemoglobin threshold of 7-8 g/dL is strong. thrombopoietin (TPO) receptor agonists have shown promise in increasing platelet levels and reducing transfusions preprocedurally, although have not specifically been found to reduce bleeding risk. Data for viscoelastic testing (VET)-guided transfusions appear favorable for reducing blood transfusion requirements prior to minor procedures and during orthotopic liver transplantation. Hemostatic agents such as recombinant factor VIIa, prothrombin complex concentrates, and tranexamic acid have been examined but their role in cirrhotic patients is unclear. Other areas of growing interest include balanced ratio and whole blood transfusion. In the following manuscript, we summarize the most up to date evidence for threshold-guided, VET-guided, balanced-ratio, and whole blood transfusions as well as the use of hemostatic agents in cirrhotic patients to provide practice guidance to clinicians.

Liver Diseases and the Hemostasis (Rewiew) Part 1. Non-Cholestatic Diseases of the Liver and Hemostasis

In liver diseases, most commonly in the terminal stage of liver failure, a variety of hemostatic defects affecting almost all parts of the blood coagulation system are developing. This leads to diminishing the capabilities of patients with liver diseases to correctly maintain the hemostatic balance.The severity of hemostatic disorders depends on the nosological form and degree of a liver damage. Depending on the imbalance of the hemostasis system and accumulated clinical/laboratory data, patients with liver diseases can be subdivided into three groups as exhibiting: 1. non-cholestatic liver damage; 2. cholestatic liver damage and 3. liver damage of vascular origin.The first part of the review discusses multiple alterations in the hemostasis system in patients with noncholestatic liver diseases, which are commonly accompanied by hypocoagulation.

Risk Factors for Intracardiac Thrombus During Liver Transplantation

Intracardiac thrombus (ICT) is an intraoperative complication with high mortality that occurs during orthotopic liver transplantation (OLT). Patients with end-stage liver disease have compromised coagulation pathways, and when combined with stressors of surgery, thrombi can form. However, it is unknown which patients are most likely to develop ICT. We performed a retrospective cohort study of all OLT patients at our hospital from 2010 to 2017 to identify risk factors for ICT. An analysis was performed with conventional bivariate tests and logistic regression. The incidence of ICT during OLT was 4.2% (22/528) with a 45.5% (10/22) mortality. Patients who developed ICT had higher physiologic Model for End-Stage Liver Disease scores at the time of transplant (25.1 versus 32.4; P = 0.004), received grafts from donors with a higher body mass index (28.1 versus 32.2 kg/m² ; P = 0.007), and had longer intraoperative warm ischemia times (53.1 versus 67.5 minutes; P = 0.001). The odds of developing ICT were significantly lower after administration of intravenous (IV) heparin prior to inferior vena cava (IVC) clamping compared with no administration of heparin (odds ratio, 0.25; 95% confidence interval, 0.08-0.75; P = 0.01). In conclusion, the incidence of ICT at our institution is higher than previously reported, which may be explained by our routine use of transesophageal echocardiography. Although many factors associated with ICT in this study are nonmodifiable, administration of IV heparin prior to IVC cross-clamping is modifiable and was found to be protective. Further studies will be needed to confirm findings and ultimately aid in preventing these lethal events.

Impedance Aggregometry Reveals Increased Platelet Aggregation during Liver Transplantation

In patients presenting for liver transplantation, increased platelet aggregation as well as thrombocytopenia have been demonstrated, but bedside assays have not been investigated. We compared platelet aggregation in liver transplantation patients and control surgical patients using impedance aggregometry. We hypothesized that platelet activity is not altered during liver transplantation. After the allowance of the ethics committee, platelet aggregation was determined using impedance aggregometry with the activators ristocetin, adenosine diphosphate (ADP), arachidonic acid, collagen, and thrombin receptor-activating peptide (TRAP) in liver transplantation patients at four time points (start of surgery, anhepatic phase, reperfusion, end of surgery) and in control surgical patients. Moreover, platelet count was determined using a Coulter counter. To compensate for the thrombocytopenia often present in patients presenting for liver transplantation, the ratio between impedance aggregometry finding and platelet count was used. For statistical evaluation, the t-test or the Mann–Whitney U-test were used, as appropriate. Platelet aggregation ratio showed a 3.1-fold increase in liver transplantation patients (n = 37) in comparison to control surgical patients (n = 10) when ristocetin was used as the activator (p = 0.001). Moreover, an approximately twofold increase of ADP-, arachidonic acid-, collagen-, and TRAP-induced platelet aggregation ratio was determined. Platelet aggregation normalized at the end of the transplantation procedure. Impedance aggregometry revealed a markedly increased platelet aggregation in some liver transplantation patients and might be suitable to guide platelet transfusion and antiplatelet therapy.

Inherited thrombophilia and portal vein thrombosis in cirrhosis: A systematic review and meta-analysis

BACKGROUND

Portal vein thrombosis (PVT) is common in cirrhosis. PVT is associated with high morbidity and mortality. Individual reports suggest that PVT occurs more frequently in patients with cirrhosis and inherited thrombophilia. The relationship between cirrhosis, PVT development, and inherited thrombophilia was explored in this study. The aim of the study was to determine whether cirrhotic patients with nontumoral PVT have an increased rate of inherited thrombophilia.

METHODS

Studies were identified by searching electronic databases up to October 2017 with English language and human subject restrictions. Two independent reviewers screened citations and extracted data. Magnitude of effect was calculated to obtain aggregate estimates of effect size and 95% confidence intervals (CIs). Between-study variability and heterogeneity were assessed.

RESULTS

Of 2893 citations identified, 9 studies composed of 1929 subjects with cirrhosis were included. The overall prevalence of PVT was 6.5% (n = 125). Both prothrombin G20210A mutation (odds ratio [OR], 2.43; 95% CI, 1.07-5.53; P = 0.03) and factor V Leiden (FVL) (OR, 1.98; 95% CI, 1.06-3.68; P = 0.03) were significantly associated with PVT risk. Methyltetrahydrofolate reductase C677T mutation was not associated with increased PVT risk. No heterogeneity or publication bias was observed. One important study with opposite findings could not be included due to lack of primary data.

CONCLUSIONS

FVL and PTG20210A mutation were associated with increased PVT risk in patients with cirrhosis. This finding reframes the role of inherited thrombophilia in PVT development in patients with cirrhosis. Future prospective studies investigating screening for inherited thrombophilia in all cirrhosis patients with PVT seem warranted.

Clinical Protocol to Prevent Thrombogenic Effect of Liver-Derived Mesenchymal Cells for Cell-Based Therapies

The efficacy of mesenchymal stem cell infusion is currently tested in numerous clinical trials. However, therapy-induced thrombotic consequences have been reported in several patients. The aim of this study was to optimize protocols for heterologous human adult liver-derived progenitor cell (HHALPC) infusion, in order to eliminate acute thrombogenesis in liver-based metabolic or acute decompensated cirrhotic (ADC) patients. In rats, thrombotic effects were absent when HHALPCs were infused at low cell dose (5 × 10⁶ cells/kg), or at high cell dose (5 × 10⁷ cells/kg) when combined with anticoagulants. When HHALPCs were exposed to human blood in a whole blood perfusion assay, blocking of the tissue factor (TF) coagulation pathway suppressed fibrin generation and platelet activation. In a Chandler tubing loop model, HHALPCs induced less explosive activation of coagulation with blood from ADC patients, when compared to blood from healthy controls, without alterations in coagulation factor levels other than fibrinogen. These studies confirm a link between TF and thrombogenesis, when TF-expressing cells are exposed to human blood. This phenomenon however, could be controlled using either a low, or a high cell dose combined with anticoagulants. In clinical practice, this points to the suitability of a low HHALPC dose infusion to cirrhotic patients, provided that platelet and fibrinogen levels are monitored.

Response patterns of routinely measured inflammatory and coagulatory parameters in sepsis

Background

Sepsis is characterized by a pro-inflammatory and pro-coagulatory shift which can induce life-threatening complications. Close monitoring and risk stratification of sepsis patients is crucial for proper treatment and consequently patient outcome. Therefore, this study focuses on the response patterns of inflammatory and coagulatory parameters used in clinical routines to estimate the course of sepsis.

Methods

A total of 1,110 patients diagnosed with sepsis were retrospectively analyzed to identify response patterns for risk stratification of routine parameters measured at the peak level of C-reactive protein. Cluster analysis was used and the differences in the patient characteristics and 28-day survival were assessed. Cox proportional hazards regression model for survival stratified by the clusters was performed.

Results

The analyses revealed the parameters to have five distinct response patterns. These clusters reflect the etiology as well as the course of sepsis associated with different mortalities. Here, impairment of the liver plays a crucial role in the ability to appropriately respond to sepsis. Of the routinely measured parameters, C-reactive protein and antithrombin seem to be unspecific for stratification of septic patients. Adjusted for the individual clusters, survival was associated with an increase in fibrinogen (p = 0.0042), platelets (p = 0.0003) and PT (p = 0.001) as well as a decrease in leukocytes (p = 0.034).

Conclusions

This study reveals that patients have distinct response patterns of inflammatory and coagulatory parameters depending on disease etiology. These patterns are associated with different mortalities although the patients have similar levels of C-reactive protein. Independently of the type of response, good coagulatory capacity seems to be crucial for patient survival.

Safety of coagulation factor concentrates guided by ROTEM™-analyses in liver transplantation: results from 372 procedures

Background

Most centres use fresh frozen plasma (FFP) based protocols to prevent or treat haemostatic disturbances during liver transplantation. In the present study, we used a rotational thrombelastometry (ROTEM™, TEM, Munich, Germany) guided haemostasis management with fibrinogen concentrates, prothrombin complex concentrates (PCC), platelet concentrates and tranexamic acid without FFP usage and determined the effect on 30 day mortality.

Methods

Retrospective data analysis with 372 consecutive adult liver transplant patients performed between 2007 and 2011.

Results

Thrombelastometry guided coagulation management resulted in a transfusion rate for fibrinogen concentrates in 50.2%, PCC in 18.8%, platelet concentrates in 21.2%, tranexamic acid in 4.5%, and red blood cell concentrates in 59.4%. 30 day mortality for the whole cohort was 14.2%. The univariate analyses indicated that nonsurvivors received significantly more fibrinogen concentrates, PCC, red blood cell concentrates, platelet concentrates, and infusion volume, and had a higher MELD score. However, association with mortality was weak as evidenced by receiver operating characteristic curve analyses. Further univariate analyses demonstrated, that up to 8 g of fibrinogen did not increase mortality compared to patients not receiving the coagulation factor. Multivariate analysis demonstrated that platelet concentrates (p = 0.0002, OR 1.87 per unit), infused volume (p = 0.0004, OR = 1.13 per litre), and MELD score (p = 0.024; OR 1.039) are independent predictors for mortality. Fibrinogen concentrates, PCC, and red blood cell concentrates were ruled out as independent risk factors.

Conclusions

ROTEM™ guided substitution with fibrinogen concentrates and PCC does not negatively affect mortality after liver transplantation, while the well-known deleterious effect associated with platelet concentrates was confirmed.

Recombinant human soluble thrombomodulin ameliorates acetaminophen-induced liver toxicity in mice

Recombinant human soluble thrombomodulin alpha (rhTM) has been developed as an anticoagulant with anti-inflammatory activity. Notably, acetaminophen (APAP) -induced liver disease (AILI) is caused by direct metabolite-induced hepatotoxicity as well as hepatic hyper-coagulation. To evaluate the utility of anticoagulant for the treatment of AILI, rhTM was administered in a mouse AILI model and liver damage was analyzed. AILI was induced in 8-week-old mice by intraperitoneal injection of APAP. rhTM (20 mg/kg) or placebo was injected at the same time as APAP administration. Serum alanine aminotransferase, fibrin degradation products and high-mobility group box 1 levels were significantly decreased in the rhTM-treated group compared with the control group. Furthermore, rhTM reduced the necrotic area and fibrin deposition in liver sections. rhTM suppressed the mRNA expression of heme oxygenase-1, plasminogen activator inhibitor type-1, tissue factors, and inflammatory cytokines compared with the control group. rhTM did not change the hepatic GSH content at 2 h after APAP injection, but restored them at 4 h after the insult. rhTM ameliorated liver damage in mice with AILI, probably via the improvement in liver perfusion induced by it's anticoagulant acitivity, which can lead to the suppression of secondary liver damage.

Bleeding risk and complications associated with percutaneous ultrasound-guided liver biopsy in cats

OBJECTIVES

Liver biopsy is necessary for a diagnosis of liver disease; however, post-biopsy bleeding is a concern. The aim of this study was to describe the extent of bleeding and the occurrence of complications after percutaneous ultrasound-guided liver biopsy (PUGLB) in cats.

METHODS

The medical records of 30 cats that had a PUGLB were retrospectively reviewed. Using human guidelines, bleeding was classified as minor or major when the absolute change in packed cell volume (ΔPCV) was <0 and >-6% or ≤-6%, respectively. Complications were defined as physiologic compromise necessitating an intervention, or death. The relationship between ΔPCV and the occurrence of complications and the signalment, initial PCV, coagulation parameters, serum liver enzymes and bilirubin, number of biopsies, histological diagnosis, ultrasound findings, radiologist experience, concurrent procedures and vitamin K administration were assessed using Fisher's exact test, ANOVA and Pearson's correlation coefficient, with a P value <0.05 considered significant.

RESULTS

All cats had a decrease in PCV after biopsy. The mean ΔPCV was -6.9% ± 4.1%. Minor and major bleeding occurred in 13/30 (43.3%) and 17/30 (56.7%) cats, respectively, and non-lethal bleeding complications occurred in 5/30 (16.7%). Cats with complications had a lower pre-biopsy PCV ( P <0.003). Major bleeding was more likely with a diagnosis of hepatic lipidosis ( P = 0.03). There was no correlation between ΔPCV or complications and signalment, coagulation parameters, serum parameters, number of biopsies, ultrasound findings, radiologist experience, concurrent procedures and vitamin K administration.

CONCLUSIONS AND RELEVANCE

PUGLB is a relatively safe procedure in cats, although many cats have a subclinical decrease in PCV. As conventional coagulation tests did not predict complications or the magnitude of ΔPCV, there is a need for more sensitive indicators of bleeding risk in cats undergoing PUGLB.

Point-of-care haemostasis monitoring during liver transplantation is cost effective

Background Optimal haemostasis management in orthotropic liver transplant (OLT) could reduce blood loss and transfusion volume, improve patient outcomes and reduce cost. Methods We performed a study including 336 OLTs to evaluate the clinical and cost effectiveness of a new point-of-care (POC)-based haemostatic management approach in OLT patients. Results In terms of health benefit we found that the new approach showed a significant reduction in transfusion requirements (red blood cell transfusion units were reduced from 5.3±4.6 to 2.8±2.9 [p<0.001], free frozen plasma from 3.1±3.3 to 0.4±1.0 [p<0.001] and platelets from 2.9±3.9 to 0.4±0.9 [p<0.001], transfusion avoidance, 9.7% vs. 29.1% [p<0.001] and massive transfusion, 14.5% vs. 3.8% [p=0.001]); we also found a significant improvement in patient outcomes, such, reoperation for bleeding or acute-kidney-failure (8.3% vs. 2.4%, p=0.015; 33.6% vs. 5.4%, p<0.001), with a significant reduction in the length of the hospital total stay (40.6±13.8 days vs. 38.2±14.4 days, p=0.001). The lowest cost incurred was observed with the new approach (€73,038.80 vs. €158,912.90) with significant patient saving associated to transfusion avoidance (€1278.36), ICU-stay (€3037.26), total-stay (€3800.76) and reoperation for bleeding (€80,899.64). Conclusions POC haemostatic monitoring during OLT is cost effective.

ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs

This consensus statement on chronic hepatitis (CH) in dogs is based on the expert opinion of 7 specialists with extensive experience in diagnosing, treating, and conducting clinical research in hepatology in dogs. It was generated from expert opinion and information gathered from searching of PubMed for manuscripts on CH, the Veterinary Information Network for abstracts and conference proceeding from annual meetings of the American College of Veterinary Medicine and the European College of Veterinary Medicine, and selected manuscripts from the human literature on CH. The panel recognizes that the diagnosis and treatment of CH in the dog is a complex process that requires integration of clinical presentation with clinical pathology, diagnostic imaging, and hepatic biopsy. Essential to this process is an index of suspicion for CH, knowledge of how to best collect tissue samples, access to a pathologist with experience in assessing hepatic histopathology, knowledge of reasonable medical interventions, and a strategy for monitoring treatment response and complications.

Controversies in anticoagulation therapy in patients with cirrhosis

PURPOSE OF REVIEW

This article aims to review the latest literature on prophylactic and therapeutic anticoagulation and the safety profile of anticoagulants in patients with cirrhosis.

RECENT FINDINGS

The understanding of hematological hemostasis is cirrhotic patients has changed drastically in recent years. Although in the past, cirrhotic patients were often considered to be 'auto-anticoagulated' and at higher risk of bleeding, recent studies have demonstrated that there may be a rebalance in procoagulation and anticoagulation factors in patients with cirrhosis. This, and clinical experience, suggest that cirrhotic patients are at risk of development of venous thrombosis, pulmonary embolism and ischemic strokes and as such, the best management approaches in these patients remains controversial. The bulk of the data suggest that patients with cirrhosis who are at risk for thrombotic or embolic complications should be anticoagulated. However, it is imperative that they be closely monitored.

SUMMARY

The medical literature on anticoagulation in patients with liver cirrhosis is conflicting and limited to small sample observational studies. However, most studies suggest that in patients with early stages of liver cirrhosis and no history of varices, anticoagulation appears to be well tolerated.

Effectiveness of venous thromboembolism prophylaxis in patients with liver disease

BACKGROUND

Patients with liver disease are concomitantly at increased risk of venous thromboembolism (VTE) and bleeding events due to changes in the balance of pro- and anti-hemostatic substances. As such, recommendations for the use of pharmacological VTE prophylaxis are lacking. Recent studies have found no difference in rates of VTE in those receiving and not receiving pharmacological VTE prophylaxis, though most studies have been small. Thus, our study sought to establish if pharmacological VTE prophylaxis is effective and safe in patients with liver disease.

AIM

To determine if there is net clinical benefit to providing pharmacological VTE prophylaxis to cirrhotic patients.

METHODS

In this retrospective study, 1806 patients were propensity matched to assess if pharmacological VTE prophylaxis is effective and safe in patients with cirrhosis. Patients were divided and evaluated based on receipt of pharmacological VTE prophylaxis.

RESULTS

The composite primary outcome of VTE or major bleeding was more common in the no prophylaxis group than the prophylaxis group (8.7% vs 5.1%, P = 0.002), though this outcome was driven by higher rates of major bleeding (6.9% vs 2.9%, P < 0.001) rather than VTE (1.9% vs 2.2%, P = 0.62). There was no difference in length of stay or in-hospital mortality between groups. Pharmacological VTE prophylaxis was independently associated with lower rates of major bleeding (OR = 0.42, 95%CI: 0.25-0.68, P = 0.0005), but was not protective against VTE on multivariable analysis.

CONCLUSION

Pharmacological VTE prophylaxis was not associated with a significant reduction in the rate of VTE in patients with liver disease, though no increase in major bleeding events was observed.

Fibrinolysis during liver transplantation: analysis by the Thrombodynamics method

An issue in orthotopic liver transplantation (OLT) is the diagnosis of hyperfibrinolysis. The Thrombodynamics-4D assay (TD4D) is a videomicroscopy system allowing the dynamic analysis of fibrin clot. Fibrinolysis is highlighted by a change in clot intensity. The aim of this observational study was to evaluate the TD4D as a tool to diagnose fibrinolysis during OLT. Thirty consecutive patients were included. We studied a subset of 41 samples from 13 patients who demonstrated hyperfibrinolysis during OLT by global fibrinolytic capacity studied by the Lysis Timer (GFC/LT) and/or euglobulin clot lysis time (ECLT) and/or EXTEM maximum lysis (EXTEM ML) on ROTEM. Three samples exhibited fibrinolysis. They exhibited significantly shorter ECLT, higher lysis on EXTEM graphs, shorter GFC/LT clot lysis time and higher t-PA activity values. After adding urokinase, 13 samples exhibited fibrinolysis. In conclusion, TD4D allows the dynamic analysis of fibrin clot formation and lysis. It only recognises the most severe forms of hyperfibrinolysis during OLT.

Perioperative hemostatic management in the cirrhotic patient: a position paper on behalf of the Liver Intensive Care Group of Europe (LICAGE)

Recent data demonstrated that amongst patients undergoing elective surgery the prevalence of cirrhosis is 0.8% equating to approximately 25 million cirrhotic patients undergoing surgery each year worldwide. Overall, the presence of cirrhosis is independently associated with 47% increased risk of postoperative complications and over two and a half-increased risk of in-hospital mortality in patients undergoing elective surgery. In particular, perioperative patients with chronic liver disease have long been assumed to have a major bleeding risk on the basis of abnormal results for standard tests of hemostasis. However, recent evidence outlined significant changes to traditional knowledge and beliefs and, nowadays, with more sophisticated laboratory tests, it has been shown that patients with chronic liver disease may be in hemostatic balance as a result of concomitant changes in both pro- and antihemostatic pathways. The aim of this paper endorsed by the Liver Intensive Care Group of Europe was to provide an up-to-date overview of coagulation management in perioperative patients with chronic liver disease focusing on patient blood management, monitoring of hemostasis, and current role of hemostatic agents.

Fibrinolysis Shutdown Is Associated With Thrombotic and Hemorrhagic Complications and Poorer Outcomes After Liver Transplantation

Detrimental consequences of hypofibrinolysis, also known as fibrinolysis shutdown (FS), have recently arisen, and its significance in liver transplantation (LT) remains unknown. To fill this gap, this retrospective study included 166 adults who received transplants between 2016 and 2018 for whom baseline thromboelastography was available. On the basis of percent of clot lysis 30 minutes after maximal amplitude, patients were stratified into 3 fibrinolysis phenotypes: FS, physiologic fibrinolysis, and hyperfibrinolysis. FS occurred in 71.7% of recipients, followed by physiologic fibrinolysis in 19.9% and hyperfibrinolysis in 8.4%. Intraoperative and postoperative venous thrombosis events occurred exclusively in recipients with the FS phenotype. Intraoperative thrombosis occurred with an overall incidence of 4.8% and was associated with 25.0% in-hospital mortality. Incidence of postoperative venous thrombosis within the first month was deep venous thrombosis/pulmonary embolism (PE; 4.8%) and portal vein thrombosis/hepatic vein thrombosis (1.8%). Massive transfusion of ≥20 units packed red blood cells was required in 11.8% of recipients with FS compared with none in the other 2 phenotype groups (P = 0.01). Multivariate analysis identified 2 pretransplant risk factors for FS: platelet count and nonalcoholic steatohepatitis/cryptogenic cirrhosis. Recursive partitioning identified a critical platelet cutoff value of 50 × 109 /L to be associated with FS phenotype. The hyperfibrinolysis phenotype was associated with the lowest 1-year survival (85.7%), followed by FS (95.0%) and physiologic fibrinolysis (97.0%). Infection/multisystem organ failure was the predominant cause of death; in the FS group, 1 patient died of exsanguination, and 1 patient died of massive intraoperative PE. In conclusion, there is a strong association between FS and thrombohemorrhagic complications and poorer outcomes after LT.

Prothrombin Complex Concentrates for Coagulopathy in Liver Disease: Single-Center, Clinical Experience in 105 Patients

Patients with liver disease frequently develop coagulopathy, and fresh frozen plasma is traditionally used for correction of coagulopathy to manage and prevent bleeding. Prothrombin complex concentrates (PCCs) offer an attractive alternative because they are more readily available and avoid large-volume transfusion. This retrospective, single-center study reviewed clinical use of PCC in patients with acute/chronic liver disease. A total of 105 patients with 194 episodes of PCC administration were reviewed. Data pertaining to indication, dosing, effectiveness, and safety were collected. The effect of PCC on coagulation was analyzed in patients for whom coagulation results were available 7 hours before and after PCC. Data on thromboembolic events and mortality within 4 weeks of PCC administration were captured. Most patients (77%) had chronic liver disease; the remainder had acute liver failure. Indications for PCC were preprocedure prophylaxis and treatment for active/recent bleeding in 48% and 52% of 194 treatment episodes, respectively. The median dose of PCC administered was 22 IU/kg (interquartile range, 16-29 IU/kg). Before PCC administration, 45% of patients had an international normalized ratio (INR) greater than 2.0, and 36% had fibrinogen levels of at least 1.5 g/L. PCC produced statistically significant reductions in prothrombin time and INR (coadministration with fibrinogen or cryoprecipitate: 3.1 versus 1.9; P < 0.001; no coadministration: 2.3 versus 1.8; P < 0.001). Three patients with multiple risk factors developed thrombotic events (hepatic artery thrombosis, incidental bilateral pulmonary embolism, nonocclusive portal vein thrombosis); there were no cardiovascular or cerebrovascular adverse events. Overall, 46 patients died of causes unrelated to PCC treatment. Conclusion: In patients with liver disease, PCC therapy was effective in improving coagulation test results without an excess of thrombotic events. Further assessment of PCC as hemostatic therapy in this setting is required.

Plasma From Patients Undergoing Liver Transplantation Is Resistant to Anticoagulant Activity of Soluble Thrombomodulin

Recombinant human soluble thrombomodulin (ART-123) is an anticoagulant and anti-inflammatory agent clinically used for treatment of disseminated intravascular coagulation. Preclinical studies have shown that ART-123 reduces hepatic ischemia/reperfusion. Although ART-123 may therefore have clinical benefit in orthotopic liver transplantation, the substantial alterations in the hemostatic system may complicate its use in this setting. Here, we studied the in vitro effect of ART-123 on coagulation of patients with end-stage liver disease undergoing liver transplantation. Ten patients with end-stage liver disease undergoing liver transplantation were included in this study. Plasma samples of 10 healthy individuals were included to establish reference values. Different concentrations of ART-123 were added to plasma samples, and peak thrombin generation and clot lysis times (CLTs) were determined. In patient samples, plasma was profoundly resistant to the anticoagulant action of ART-123, as reflected by significantly higher median inhibitory concentration (IC₅₀ ) values of peak thrombin generation compared with controls. This might be partially explained by low levels of protein C, protein S, and elevated levels of factor VIII during transplantation. Intraoperative levels of thrombin activatable fibrinolysis inhibitor were significantly lower when compared with controls. However, ART-123-dependent prolongation of CLTs was not significantly different from healthy controls. In conclusion, this study suggests that ART-123 is unlikely to provoke bleeding in patients undergoing liver transplantation because proposed clinical dosages have a virtually absent anticoagulant effect in these patients. Clinical studies are required to confirm the safety of ART-123 and efficacy on alleviating ischemia/reperfusion injury during liver transplantation.

Elevated D-dimer is associated with increased 28-day mortality in acute-on-chronic liver failure in China: a retrospective study

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a syndrome characterized by profound disrupted coagulation and fibrinolysis. Fibrinolytic marker D-dimer is increased in critically ill patients with cirrhosis which is associated with poorer prognosis. We aim to determine the potential association of D-dimer with the 28-day mortality in ACLF patients.

METHODS

In a single center retrospective study performed in China, we collected data of 115 patients with ACLF from October 1, 2012 to December 31, 2016. We investigated correlations between D-dimer and other laboratory tests and prognostic scores. The relationship between D-dimer and 28-day mortality was explored by smoothing plot with an adjustment for potential confounders. Logistic regression analyses with crude and adjusted models were performed to explore the association of D-dimer with 28-day mortality in ACLF patients.

RESULTS

In ACLF patients, D-dimer at admission was correlated with all prognostic scores (MELD-Na: r = 0.385, P < 0.001; CLIF-C ADs: r = 0.443, P < 0.001; CLIF-C ACLFs: r = 0.375, P < 0.001). A nonlinear relation between D-dimer and 28-day mortality was found with a turning point at 6.5 mg/L FEU. D-dimer level was independently associated with 28-day mortality with an adjusted odds ratio of [1.4 (1.0-1.9), P = 0.030] as continuous variable and [10.3 (1.3, 81.5), P = 0.028] as a classified variable with the cut-off of 6.5 mg/L FEU. An elevated D-dimer within the following 10 days also tended to be associated with higher risk of 28-day mortality [OR: 27.5 (0.9, 814.9), P = 0.055].

CONCLUSIONS

Elevated D-dimer levels was associated with increased risk of 28-day mortality in patients with ACLF in China.

Correlation of early ROTEM parameters with conventional coagulation tests in patients with chronic liver disease undergoing liver transplant

BACKGROUND AND AIMS

Viscoelastic tests such as rotational thromboelastometry (ROTEM) provide a quick and holistic assessment of coagulation status to guide transfusion during liver transplant (LT). Conventional coagulation tests (CCTs) measure single parameters in isolation, and also the results are delayed hampering management of patients during surgery. We evaluated the correlation of early ROTEM-derived parameters with CCTs and also assessed the ability of ROTEM-derived parameters to predict thrombocytopaenia and hypofibrinogenaemia during LT in patients with end-stage liver disease (ESLD).

METHODS

This retrospective study was carried out in 100 patients with decompensated ESLD undergoing LT. Correlation between CCTs and ROTEM parameters was analyzed. Receiver operating characteristic curves with area under the curve were used to determine the cut-off values of A5 andA10 on EXTEM and FIBTEM.

RESULTS

The values of A5EXTEM and A10EXTEM highly correlated with fibrinogen levels and platelet count, whereas A5FIBTEM and A10FIBTEM correlated well with fibrinogen levels. A5EXTEM<21 mm and A10EXTEM<28 mm correlated with a platelet count <75,000 mm-3, whereas A5EXTEM<18 mm and A10EXTEM<25 mm correlated with a platelet count <50,000 mm-3. Fibrinogen levels <100 mg/dL better correlated with A5FIBTEM<5 mm, A10FIBTEM<6 mm, A5EXTEM<21 mm and A10EXTEM<30 mm.

CONCLUSION

Early ROTEM parameters A5 and A10 of both EXTEM and FIBTEM had an excellent correlation with thrombocytopaenia and hypofibrinogenaemia and may potentially guide early transfusion of relevant blood products during LT.

Management of haemostatic alterations and associated disorders in cirrhosis in Spain: A national survey

BACKGROUND

Knowledge of haematological abnormalities in cirrhosis has greatly improved in recent years.

AIMS

To evaluate how Spanish Digestive Disease specialists manage haemostatic alterations and associated disorders in patients with cirrhosis.

METHODS

All members of the Spanish Association for the Study of the Liver and Spanish Society of Digestive Pathology were invited to fill in a web-based questionnaire.

RESULTS

135 professionals, 93 hepatologists and 42 non-hepatologists responded to the survey. The concept of rebalanced haemostasis was known by 74.8% of them. Most specialists corrected the INR and thrombocytopenia before invasive procedures with moderate risk of bleeding or major surgery and in severe gastrointestinal bleeding. The threshold of platelets and, especially, INR used to administer blood products varied greatly. Pharmacological prophylaxis of venous thromboembolism prevailed, but it was highly dependent on the INR and platelet figures. Most participants initiated anticoagulation regardless of the degree of portal vein thrombosis, even in patients ineligible for transplantation. In potential candidates, only 56% maintained it indefinitely or until liver transplantation. No major differences between hepatologists and non-hepatologists were found.

CONCLUSIONS

A significant variability and certain deviation from current guidelines was observed among Spanish Digestive Disease specialists regarding management of haemostatic alterations and associated disorders in cirrhosis.

Patients With Budd-Chiari Syndrome Have Variable Coagulation Status on Thromboelastography at Diagnosis

BACKGROUND & AIMS

Budd-Chiari Syndrome (BCS) is considered a thrombophilic state, and most patients with BCS have thrombophilic disorder. Liver dysfunction-related coagulopathy makes coagulation function unpredictable in BCS. Thromboelastography (TEG) assesses the dynamics, strength, and stability of clot formation. We conducted a pilot study using TEG to evaluate coagulation status in patients with BCS.

METHODS

Fifty-one patients with newly diagnosed BCS (age 32.3 [10.7] years; 23 men) underwent TEG (TEG®5000 Hemostasis Analyzer®, USA), and its components were analyzed and correlated with clinical profile and thrombophilic disorders. Patients who had received anticoagulation, antiplatelet drugs, or radiological intervention were excluded.

RESULTS

Twenty-nine patients had normal TEG, 11 had procoagulant TEG, and 11 had hypocoagulant TEG. Among patients with hypocoagulant TEG, Coagulation Index (CI) was < -3 in 11 patients, R was >8 min in 6 patients, K was >3 min in 9 patients, alpha <55 in 9 patients, and MA <51 in 7 patients; among those with hypercoagulant TEG, CI was >3 in 3 patients, R < 2 min in 2 patients, K <1 min in 2 patients, alpha >78 in none, and MA >69 mm in 7 patients. TEG findings were similar in patients with and without thrombophilic disorder. The mean platelet count (1.75, 2.22, and 1.79 × 10⁵/mm³; P = 0.13) and international normalized ratio (1.27, 1.34, and 1.28, P = 0.69) were similar in those with procoagulant, normal, and hypocoagulant TEG. Two patients in Rotterdam class-III had abnormal LY30. Other clinical parameters did not correlate with TEG findings.

CONCLUSION

Patients with BCS are heterogeneous with respect to coagulation status, with one-fifth of patients are hypocoagulant on TEG. Patients with advanced disease may have accelerated fibrinolysis.

Monitoring of coagulation by intraoperative thromboelastometry of liver transplantation in a patient using warfarin – case report

Introduction

Case report

Discussion

In vitro efficacy of pro- and anticoagulant strategies in compensated and acutely ill patients with cirrhosis

BACKGROUND & AIMS

A simultaneous decline in pro- and anticoagulant drivers in patients with liver diseases results in a "rebalanced" haemostatic system, even in acutely ill patients. Nevertheless, both bleeding and thrombotic events are common. Here, we explored efficacy of pro- and antihaemostatic strategies in compensated and acutely ill cirrhotics which may be unpredictable given the profound haemostatic changes.

METHODS

We tested the effects in vitro of the addition of clinically relevant doses of commonly used pro- and antihaemostatic strategies in plasma from healthy individuals (n = 30) and patients with compensated (n = 18) and acutely decompensated cirrhosis (n = 18), and acute-on-chronic liver failure (n = 10). We used thrombin generation tests and fibrin clot permeability assays to assess potency of various approaches.

RESULTS

Fresh frozen plasma and recombinant factor VIIa modestly increased thrombin generation (10%-20%). Prothrombin complex concentrate increased thrombin generation two-fold in controls and 2-4-fold in patients. Clot permeability decreased after addition of fibrinogen concentrate by 51% in controls and by 50%-60% in patients. Low molecular weight heparin decreased thrombin generation by 18% in controls and by 23%-54% in patients. Similarly, dabigatran decreased thrombin generation by 33% in controls and by 47%-100% in patients. In contrast, rivaroxaban decreased thrombin generation by 55% in controls, but only by 11%-38% in patients.

CONCLUSIONS

These in vitro data suggest little prohaemostatic effect of fresh frozen plasma and recombinant factor VIIa in acutely ill cirrhotics, whereas prothrombin complex concentrate and fibrinogen concentrate clearly improved haemostasis. Furthermore, our data suggest the requirement for dose adjustments of commonly used anticoagulants in these patients.

A retrospective analysis of re-exploration after living donor right lobe liver transplantation: incidence, causes, outcomes, and risk factors

Despite technical difficulties, right lobe liver grafting is preferred in living donor liver transplantation because of the graft size. Re-exploration after living donor right lobe liver transplantation (LRLT) has never been separately analyzed. We aimed to analyze the incidence, causes, outcomes, and risk factors of re-exploration after LRLT. We reviewed medical records of 1016 LRLT recipients from October 2003 to July 2017 and identified recipients who underwent re-exploration within hospital stay. Separate analyses were also performed according to cause of re-exploration. The overall incidence of re-exploration was 17.0% (173/1016). The most common cause of re-exploration was bleeding (50%). Overall re-exploration was associated with clinical outcome, but different results were shown on analyses according to cause of re-exploration. Risk factors of re-exploration were underlying hepatocellular carcinoma and operative duration [Odds ratio (OR), 1.49; 95% confidence interval (CI), 1.05-2.12; P = 0.03, and OR, 1.002; 95% CI, 1.001-1.004; P = 0.0023, respectively]. Re-exploration after LRLT is relatively common, and is strongly associated with mortality and graft failure.

Pathogenesis and diagnosis of disseminated intravascular coagulation

Several clinical conditions, in particular those associated with a systemic inflammatory response, can cause some degree of activation of coagulation but when the procoagulant stimulus is sufficiently severe and overcomes the natural anticoagulant mechanisms of coagulation, disseminated intravascular coagulation (DIC) may occur. The clinical manifestations of DIC encompass multiorgan dysfunction caused by fibrin-platelet clots in the microcirculation, and bleeding caused by consumption of platelets and coagulation factors. Molecular mechanisms that play a role in inflammation-induced effects on coagulation have been recognized in much detail. Exposure of blood to tissue factor is the most common trigger, whereas the intravascular coagulation is propagated due to loss of function of physiological anticoagulants and impaired fibrinolysis. In patients with DIC, various abnormalities in routine coagulation parameters may be observed, including thrombocytopenia, prolonged global coagulation assays, or high levels of fibrin split products. In addition, more sophisticated tests for activation of individual factors or pathways of coagulation may point to specific involvement of these components in the pathogenesis of the disorder. A combination of readily available tests is usually sufficient in establishing the diagnosis of DIC, and for this purpose, several scoring algorithms have been developed. Some specific clinical situations may elicit coagulation responses that can be distinguished from DIC or may occur in combination with DIC, including dilutional coagulopathy, liver failure-related coagulation derangement, and thrombotic microangiopathies.

Radiotherapy for one rectal cancer patient with cirrhosis and moderate to severe thrombocytopenia: a case report

When patients with cirrhosis and severe thrombocytopenia suffer malignant tumors, there is usually no effective and feasible treatment method due to the high risk of hemorrhage. Herein, we report a case in which radiotherapy was given to a patient with a strong desire for the treatment. The patient was a 66-year-old man with a 13-year history of cirrhosis and a 10-year history of thrombocytopenia, and was diagnosed with locally advanced rectal cancer (LARC; T_4aN₁M₀, stage IIIB). The platelet count before radiotherapy was 32 × 10⁹/L, and the blood coagulation was normal. The severity of thrombocytopenia increased after 2 Gy × 7 fractions pelvic radiation, with platelet counts dropping to 16 × 10⁹/L. Platelet counts failed to return to pre-therapy levels after supporting therapy including recombinant human interleukin 11 subcutaneous injection and platelet transfusion. Although radiotherapy was discontinued eventually, the data presented here represent a valuable resource that can help inform treatment decisions for tumor patients with cirrhosis and thrombocytopenia.

The Misunderstood Coagulopathy of Liver Disease: A Review for the Acute Setting

The international normalized ratio (INR) represents a clinical tool to assess the effectiveness of vitamin-K antagonist therapy. However, it is often used in the acute setting to assess the degree of coagulopathy in patients with hepatic cirrhosis or acute liver failure. This often influences therapeutic decisions about invasive procedures or the need for potentially harmful and unnecessary transfusions of blood product. This may not represent a best-practice or evidence-based approach to patient care. The author performed a review of the literature related to the utility of INR in cirrhotic patients using several scientific search engines. Despite the commonly accepted dogma that an elevated INR in a cirrhotic patient corresponds with an increased hemorrhagic risk during the performance of invasive procedures, the literature does not support this belief. Furthermore, the need for blood-product transfusion prior to an invasive intervention is not supported by the literature, as this practice increases the risk of complications associated with a patient's hospital course. Many publications ranging from case studies to meta-analyses refute this evidence and provide examples of thrombotic events despite elevated INR values. Alternative methods, such as thromboelastogram, represent alternate means of assessing in vivo risk of hemorrhage in patients with acute or chronic liver disease in real-time in the acute setting.

Direct oral anticoagulants in patients with liver cirrhosis: A systematic review

INTRODUCTION

Anticoagulant treatment in patients with liver cirrhosis is challenging. The aim of this systematic review was to evaluate clinical outcomes of direct oral anticoagulant (DOAC) therapy in cirrhosis patients.

MATERIALS AND METHODS

A systematic search was performed in MEDLINE, Embase, and conference proceedings up to November 7th, 2017, for studies that evaluated the efficacy and safety of DOACs in cirrhosis patients with venous thromboembolism (VTE), splanchnic vein thrombosis (SVT), or atrial fibrillation (AF). Two authors independently screened titles, abstracts, and full-text articles, and assessed risk of bias. A meta-analysis could not be performed due to heterogeneity of the included studies.

RESULTS

Of the 2927 articles assessed, five retrospective cohort studies were included (n = 239, including 20 patients overlap). All studies had fair methodological quality. Two studies evaluated DOAC treatment only, and three also evaluated vitamin K antagonists (VKAs) or low-molecular-weight heparins (LMWHs). Recurrent VTE (DOAC n = 12, LMWH/VKA n = 8) or ischemic stroke (DOAC n = 37, LMWH/VKA n = 9) occurred in none of the patients. Progression of VTE was 8% with DOACs (n = 12) and 13% with VKAs and LWWH (n = 8). Recurrent SVT occurred in 0 to 4% with DOACs (n = 31). Progression of SVT was 0 to 5% with DOACs (n = 24) and 0 to 47% with VKAs and LMWH (n = 33). Major bleeding risk ranged from 4 to 15% with DOACs (n = 172) and from 7 to 28% with VKAs and LMWH (n = 67). All-cause mortality risk was 6% with DOACs (n = 36).

CONCLUSIONS

There is paucity of data on the efficacy and safety of DOACs in patients with cirrhosis. This analysis suggests that DOACs may be effective and safe for treatment of VTE, SVT, and AF in these patients.

Rotation thromboelastometry velocity curve predicts blood loss during liver transplantation

BACKGROUND

Patients undergoing liver transplantation (LT) have a high risk of bleeding. The goal of this study was to assess whether the first derivative of the velocity waveform (V-curve) generated by whole blood rotation thromboelastometry (ROTEM^®) can predict blood loss during LT.

METHODS

Preoperative V-curve parameters were retrospectively evaluated in 198 patients. Patients were divided into quartiles based on blood loss: low (LBL) in the first quartile and high (HBL) in the higher quartiles. A subgroup analysis was performed with patients stratified according to cirrhosis aetiology. A logistic regression model and receiver operator characteristics (ROC) curve were used to test the capacity of the V-curve, to discriminate between LBL and HBL.

RESULTS

In the HBL group, the V-curve showed a lower maximum velocity of clot generation (MaxVel), a lower area under maximum velocity curve (AUC), and a higher time-to-maximum velocity (t-MaxVel) than in the LBL group. t-MaxVel was the only parameter showing a capacity to discriminate between the two groups, with a ROC area of 0.69 (95% CI; 0.62-0.74). The ROC area was 0.78 (95% CI; 0.75-0.83) for the 148 patients with cirrhosis, 0.73 (0.60-0.82) for patients with viral hepatitis and 0.83 (0.78-0.96) for patients with alcoholic hepatitis, the group that showed the best discriminative capacity. Moderate but significant correlations were found between all parameters of V-curve and BL.

CONCLUSIONS

Pre-transplant V-curve obtained from ROTEM is a promising tool for predicting BL risk during LT, particularly in patients with cirrhosis.

Efficacy and tolerance of early administration of tranexamic acid in patients with cirrhosis presenting with acute upper gastrointestinal bleeding: a study protocol for a multicentre, randomised, double-blind, placebo-controlled trial (the EXARHOSE study)

INTRODUCTION

The management of acute upper gastrointestinal bleeding (UGIB) is challenging in patients with cirrhosis, as it is responsible for severe complications and high mortality rates. Tranexamic acid (TXA) may help control the bleeding by counterbalancing cirrhosis-related hyperfibrinolysis. Still, there is a lack of unbiased data to conclude on its efficacy. The aim of this study is to evaluate the efficacy of TXA in the early treatment of acute UGIB in patients with cirrhosis.

METHODS AND ANALYSIS

This study is a multicentre, randomised, double-blind, placebo-controlled trial, for adult patients with cirrhosis presenting with an acute UGIB and allocated to one of two arms: TXA or placebo (saline). Physicians from emergency mobile services, emergency departments (EDs) or intensive care units (ICUs) can include patients. Besides study intervention, standard care for UGIB will be performed as recommended. Intervention will consist an intravenous infusion of 10 mL of TXA (1 g) or saline, immediately followed by three identical intravenous infusions over 8 hours each (total dose of 4 g of TXA or 40 mL of placebo over 24 hours). Main analyses will be conducted in intention to treat on every patient included, then in modified intention to treat on patients with underlying lesion of portal hypertension visualised by endoscopy. The main objective is to show efficacy of TXA until day 5 on a composite criterion (bleeding control, rebleeding episodes and mortality). Secondary objectives aim at showing the efficacy of TXA on each individual component of the main outcome measure and others at 6 weeks and later (transjugular intrahepatic portosystemic shunt procedure, cirrhosis-specific complications, length of stay in ICU and in hospital, safety and tolerance of TXA, liver transplantation). Included patients will be followed up to 1 year after inclusion.500 patients will be necessary to show a reduction in the prevalence of the primary outcome from 30% to 18% with a bilateral alpha risk of 5% and a power of 80%.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Comité de Protection des Personnes Ile-de-France 1 (CPP-IDF1). Results will be disseminated via publications in peer-review medical journals and scientific forums.

PROTOCOL VERSION

This protocol is based on the latest version, as established on 11 October 2017 and validated by the IRB CPP Ile-de-France 1.

TRIAL REGISTRATION NUMBER

NCT03023189.

Role of the blood coagulation cascade in hepatic fibrosis

Liver is the primary source of numerous proteins that are critical for normal function of the blood coagulation cascade. Because of this, diseases of the liver, particularly when affiliated with severe complications like cirrhosis, are associated with abnormalities of blood clotting. Although conventional interpretation has inferred cirrhosis as a disorder of uniform bleeding risk, it is now increasingly appreciated as a disease wherein the coagulation cascade is precariously rebalanced. Moreover, prothrombotic risk factors are also associated with a more rapid progression of fibrosis in humans, suggesting that coagulation proteases participate in disease pathogenesis. Indeed, strong evidence drawn from experimental animal studies indicates that components of the coagulation cascade, particularly coagulation factor Xa and thrombin, drive profibrogenic events, leading to hepatic fibrosis. Here, we concisely review the evidence supporting a pathologic role for coagulation in the development of liver fibrosis and the potential mechanisms involved. Further, we highlight how studies in experimental animals may shed light on emerging clinical evidence, suggesting that beneficial effects of anticoagulation could extend beyond preventing thrombotic complications to include reducing pathologies like fibrosis.

Coagulation, Microenvironment and Liver Fibrosis

Fibrosis is the main consequence of any kind of chronic liver damage. Coagulation and thrombin generation are crucial in the physiological response to tissue injury; however, the inappropriate and uncontrolled activation of coagulation cascade may lead to fibrosis development due to the involvement of several cellular types and biochemical pathways in response to thrombin generation. In the liver, hepatic stellate cells and sinusoidal endothelial cells orchestrate fibrogenic response to chronic damage. Thrombin interacts with these cytotypes mainly through protease-activated receptors (PARs), which are expressed by endothelium, platelets and hepatic stellate cells. This review focuses on the impact of coagulation in liver fibrogenesis, describes receptors and pathways involved and explores the potential antifibrotic properties of drugs active in hemostasis in studies with cells, animal models of liver damage and humans.

Perioperative thromboprophylaxis in liver transplant patients

Improvements in surgical and anesthetic procedures have increased patient survival after liver transplantation (LT). However, the perioperative period of LT can still be affected by several complications. Among these, thromboembolic complications (intracardiac thrombosis, pulmonary embolism, hepatic artery and portal vein thrombosis) are relatively common causes of increased morbidity and mortality. The benefit of thromboprophylaxis in general surgical patients has already been established, but it is not the standard of care in LT recipients. LT is associated with a high bleeding risk, as it is performed in a setting of already unstable hemostasis. For this reason, the role of routine perioperative prophylactic anticoagulation is usually restricted. However, recent data have shown that the bleeding tendency of cirrhotic patients is not an expression of an acquired bleeding disorder but rather of coexisting factors (portal hypertension, hypervolemia and infections). Furthermore, in cirrhotic patients, the new paradigm of ''rebalanced hemostasis'' can easily tip towards hypercoagulability because of the recently described enhanced thrombin generation, procoagulant changes in fibrin structure and platelet hyperreactivity. This new coagulation balance, along with improvements in surgical techniques and critical support, has led to a dramatic reduction in transfusion requirements, and the intraoperative thromboembolic-favoring factors (venous stasis, vessels clamping, surgical injury) have increased the awareness of thrombotic complications and led clinicians to reconsider the limited use of anticoagulants or antiplatelets in the postoperative period of LT.

[Monitoring of coagulation by intraoperative thromboelastometry of liver transplantation in a patient using warfarin - case report]

INTRODUCTION

Advanced hepatic disease may - in addition to the widely recognized hemorrhagic complications - occur with thrombotic events. We describe the case of a cirrhotic patient taking warfarin and whose coagulation management during liver transplantation was guided by thromboelastometry (ROTEM^®).

CASE REPORT

A 56 year-old male patient diagnosed with alcohol cirrhosis using warfarin (2.5mg.day^-1) for partial portal vein thrombosis with the International Normalized Ratio (INR) of 2.14. At the beginning of surgery, the ROTEM^® parameters were all normal. In the anhepatic phase, EXTEM and INTEM remained normal, but FIBTEM showed reduction of amplitude after 10min and maximum clot firmness. Finally, in the neohepatic phase, there was a slight alteration in the hypocoagulability of most of the parameters of the EXTEM, INTEM and FIBTEM, besides a notable correction of the Coagulation Time (CT) in HEPTEM compared to the CT of the INTEM. Therefore, the patient did not receive any transfusion of blood products during surgery and in the postoperative period, being discharged on the 8th postoperative day.

DISCUSSION

Coagulation deficit resulting from cirrhosis distorts INR as a parameter of anticoagulation adequacy and as a determinant of the need for blood transfusion. Thus, thromboelastometry can provide important information for patient management.

Major Changes of von Willebrand Factor Multimer Distribution in Cirrhotic Patients with Stable Disease or Acute Decompensation

Background  There is an unstable balance between pro- and anti-haemostatic processes in patients with cirrhosis. We hypothesized, that in patients with acute decompensation (AD) the major alterations of von Willebrand factor (VWF) could contribute to the pro-thrombotic situation as compared to patients with stable (ST) cirrhosis.

Patients and Methods  We analysed different parameters of VWF, including detailed multimer distribution by densitometry and platelet adhesion, together with ad isintegrin-like a nd m etalloproteinase with t hrombo s pondin type-1 motifs 13 (ADAMTS13) activity and antigen and C-reactive protein (CRP) levels in patients with ST cirrhosis ( n  = 99), with AD ( n  = 54) and controls ( n  = 92).

Results  VWF antigen, ristocetin co-factor as well as collagen-binding activities were elevated in both cirrhotic groups in a stepwise manner. There was a decrease in high and an increase in low molecular weight multimer ratios in the majority of ST cirrhosis. However, in 24 out of 54 AD patients, ultra-large VWF multimers (ultra-large molecular weight multimers [ULMWM]) were found. ADAMTS13 activity in ST and AD patients without ULMWM was similar to controls (median [interquartile range; IQR]%: 98 [67–132] and 91 [60–110] vs. 106 [88–117], respectively). The presence of ULMWM in AD patients was associated with low ADAMTS13 activity [33 (24–49)%] and high CRP level [23 (7.1–83.6) mg/L]. Adhesion of normal platelets showed a stepwise increase in the presence of cirrhotic plasmas, reaching the highest level in AD patients with ULMWM.

Conclusion  Characteristic changes of VWF parameters are seen in ST cirrhosis. In AD patients, highly increased VWF and reduced ADAMTS13 activity could be found, along with the presence of ULMWM, which are possible markers and contributors of the disease progression.

Clinical Outcomes of a Pharmacy-Led Blood Factor Stewardship Program

To report the results of a pharmacist-directed blood factor stewardship program targeting off-label utilization designed to limit use to established organizational guidelines in high-risk populations. Prospective evaluation of recombinant factor VIIa and prothrombin complex concentrate orders beginning June 2013 through May 2014 and a matched retrospective cohort from June 2012 to May 2013. Matched cohorts were evaluated for 28-day mortality, change in international normalized ratio (INR), adverse events, concurrent blood product use, and cost savings. Forty-two orders for blood factor were ordered between June 2013 and May 2014, 70 orders in the year before (N = 112). Twenty eight-day mortality was not different between the cohorts: 53.9% versus 50% (P = 0.77). Blood factor use with underlying liver failure and active bleeding was strongly associated with 28-day mortality: odds ratio (95% confidence interval), 2.9 (1.5-7.14) and 2.91 (0.01-2.91), respectively. Blood products dispensed increased over the year with plasma products the most significant (1 vs. 4 P = 0.004). All other clinical outcomes were nonsignificant. An annual cost savings of $375,539 was achieved, primarily through a significant reduction in recombinant factor VIIa and avoidance in high-risk patients. Use of off-label blood factors can be controlled through a pharmacist-led stewardship program. Twenty eight-day mortality was not different between the 2 cohorts; however, identification of risk factors for death associated with blood factor use allows for restriction in high-risk populations, creates a discussion of futile care, and yields cost savings.