Established and new-generation antithrombotic drugs in patients with cirrhosis - possibilities and caveats

Prediction and prevention of post-procedural bleedings in patients with cirrhosis

Although post-procedural bleedings are infrequent in patients with cirrhosis, they are associated with significant morbidity and mortality. Therefore, predicting and preventing such bleedings is important. Established predictors of post-procedural bleeding include high-bleeding risk procedure, severe cirrhosis and high body mass index; prognostic value of anemia, acute kidney injury and bacterial infection is more uncertain. While prothrombin time and international normalized ratio do not predict post-procedural bleeding, some evidence suggests that platelet count, whole blood thrombin generation assay and viscoelastic tests may be helpful in this context. Prevention of postprocedural bleeding involves careful management of antithrombotic drugs during the periprocedural period. Patients with cirrhosis present unique challenges due to altered pharmacokinetics and pharmacodynamics of antithrombotic drugs, but there is a lack of dedicated studies specifically focused on this patient population. Guidelines for periprocedural management of antithrombotic drugs developed for patients without liver disease are thus applied to those with cirrhosis. Some technical aspects may decrease the risk of post-procedural bleeding, namely ultrasoundguidance, opting for transjugular route rather than percutaneous route, and the level of expertise of the operator. The effectiveness of platelet transfusions or thrombopoietin-receptor agonists remains uncertain. Transfusion of fresh-frozen plasma, of fibrinogen, and administration of tranexamic acid are not recommended for reducing post-procedural bleeding in patients with cirrhosis. In conclusion, prediction of post-procedural requires a global approach taking into account the patients characteristics, the risk of the procedure, and the platelet count. There is little data to support prophylactic correction of hemostasis, and dedicated studies are needed.

Direct oral anticoagulants in cirrhosis: Rationale and current evidence

Cirrhosis is a major health concern worldwide with a complex pathophysiology affecting various biological systems, including all aspects of haemostasis. Bleeding risk is mainly driven by portal hypertension, but in end-stage liver disease it is further increased by alterations in haemostatic components, including platelet function, coagulation, and fibrinolysis. Concurrently, patients with cirrhosis are prone to venous thromboembolic events (VTE) because of the altered haemostatic balance, in particular an increase in thrombin generation. In patients with cirrhosis, vitamin K antagonists (VKA) and low molecular weight heparins (LMWH) are currently the standard of care for VTE prevention, with VKA also being standard of care for stroke prevention in those with atrial fibrillation. However, direct oral anticoagulants (DOAC) could have specific advantages in this patient population. Clinical experience suggests that DOAC are a safe and possibly more effective alternative to traditional anticoagulants for the treatment of VTE in patients with compensated cirrhosis. In addition, emerging data suggest that primary prophylactic treatment with anticoagulants may improve clinical outcomes in patients with cirrhosis by reducing the risk of hepatic decompensation. The selection of the most appropriate DOAC remains to be clarified. This review focuses on the rationale for the use of DOAC in patients with cirrhosis, the specific effects of the different DOAC (as assessed by in vitro and in vivo pharmacokinetic and pharmacodynamic studies), as well as clinical outcomes in patients with cirrhosis on DOAC.

Platelet, Antiplatelet Therapy and Metabolic Dysfunction-Associated Steatotic Liver Disease: A Narrative Review

Metabolic dysfunction-associated steatotic liver disease (MASLD) is not only related to traditional cardiovascular risk factors like type 2 diabetes mellitus and obesity, but it is also an independent risk factor for the development of cardiovascular disease. MASLD has been shown to be independently related to endothelial dysfunction and atherosclerosis. MASLD is characterized by a chronic proinflammatory response that, in turn, may induce a prothrombotic state. Several mechanisms such as endothelial and platelet dysfunction, changes in the coagulative factors, lower fibrinolytic activity can contribute to induce the prothrombotic state. Platelets are players and addresses of metabolic dysregulation; obesity and insulin resistance are related to platelet hyperactivation. Furthermore, platelets can exert a direct effect on liver cells, particularly through the release of mediators from granules. Growing data in literature support the use of antiplatelet agent as a treatment for MASLD. The use of antiplatelets drugs seems to exert beneficial effects on hepatocellular carcinoma prevention in patients with MASLD, since platelets contribute to fibrosis progression and cancer development. This review aims to summarize the main data on the role of platelets in the pathogenesis of MASLD and its main complications such as cardiovascular events and the development of liver fibrosis. Furthermore, we will examine the role of antiplatelet therapy not only in the prevention and treatment of cardiovascular events but also as a possible anti-fibrotic and anti-tumor agent.

Improved Survival for Patients With Acute Upper Gastrointestinal Bleeding While on Antithrombotic Therapy: A Multicenter Prospective Cohort Study

GOALS

Aim of the study was to determine if patients with acute upper gastrointestinal bleeding (AUGIB) while on antithrombotic agents (ATs) are at higher risk for worse outcomes.

BACKGROUND

ATs are risk factors of AUGIB, but their impact on clinical outcomes is uncertain.

STUDY

Patients with AUGIB (nonvariceal, NV-AUGIB or variceal, V-AUGIB) in 50 Italian hospitals were prospectively enrolled from January 1, 2014 to December 31, 2015. Clinical data, laboratory tests, comorbidities, prognostic scores, received therapies, and outcomes (death, rebleeding, surgery/radiology, transfusions, length of hospitalization) were analyzed.

RESULTS

A total of 3324 patients (2764 NV-AUGIB, 83.2% and 560 V-AUGIB, 16.8%) were enrolled, 1399 (42.1%) on ATs. Patients taking ATs were older (75.4 vs. 62.8 y, P <0.001), had higher American Society of Anesthesiologists (ASA), Rockall and Glasgow-Blatchford scores ( P <0.001). At multivariate analysis considering comorbidities, ATs use resulted an independent protective factor against death [odds ratio (OR): 0.63, 95% confidence interval (CI): 0.45-0.87, P =0.006]. Rebleeding (5.5% vs. 5.8%, P =0.71) and need for salvage surgery/radiology (4.2% vs. 4.8%, P =0.41) were similar in the 2 groups. Considering specific ATs, low-dose aspirin was the most powerful factor lowering the death risk (OR: 0.51, 95% CI: 0.33-0.81, P =0.004). While the generic use of AT therapy did not emerge as a statistically significant independent protective factor considering separately NV-AUGIB (OR: 0.80, 95% CI: 0.56-1.13, P =0.21) and V-AUGIB (OR: 0.40, 95% CI: 0.15-1.07, P =0.068), the protective effect of low-dose aspirin was confirmed for NV-AUGIB (OR: 0.62, 95% CI: 0.41-0.94, P =0.025).

CONCLUSIONS

ATs use is an independent protective factor against death in AUGIB. The protective effect is mainly derived from low-dose aspirin.

Clinically relevant increases in the international normalized ratio and model of end-stage liver disease score by therapeutic doses of direct oral anticoagulants in patients with cirrhosis

Background

Patients with cirrhosis are increasingly using direct oral anticoagulants (DOACs) in therapeutic doses for the treatment of portal vein thrombosis or for concomitant atrial fibrillation. DOACs may affect routine diagnostic tests of coagulation including the international normalized ratio (INR). The INR is a part of the model of end-stage liver disease (MELD) score, a validated score that predicts the mortality risk in patients with cirrhosis and is used to prioritize patients for liver transplantation. DOAC-induced increases in the INR may thus lead to artificial inflation of the MELD score.

Objective

We studied the effect of DOACs on INR prolongation in patients with cirrhosis.

Methods

We spiked plasma from 20 healthy individuals and 20 patients at the start of liver transplantation with DOACs in concentrations representing peak therapeutic levels. In addition, we studied INR increases in healthy controls and patients with mild cirrhosis who received the DOAC edoxaban for 1 week for study purposes.

Results

In controls and patients, the INR increased by an ex vivo addition of a DOAC, and the INR increase in patients was proportional to the baseline INR values. The increase in INR translated to a median increase of between 3 and 10 MELD points, depending on the DOAC used. In controls and patients alike, the INR increased on the ingestion of edoxaban, which translated to an increase in 5 MELD points.

Conclusions

Taken together, DOACs result in an INR increase that translates to clinically meaningful increases in MELD points in patients with cirrhosis, and precautions to avoid artificial inflation of the MELD score in these patients are warranted.

Clinical outcomes of antithrombin III-based therapy for patients with portal vein thrombosis: A retrospective, multicenter study

AIM

The association between thrombolytic therapy and the outcome in patients with portal vein thrombosis (PVT) remains controversial. This study aimed to evaluate the outcome in patients with PVT who received antithrombin III-based therapy.

METHODS

This study was a retrospective, multicenter study to investigate the liver-related events and the survival rates in 240 patients with PVT who received the therapy.

RESULTS

The patients comprised 151 men and 89 women, with a median age of 69 years. The rate of favorable response, defined as maximum area of PVT changed to ≤75%, was 67.5% (162/240). The cumulative rates of liver-related events at 1, 2, and 3 years were 38.2%, 53.9%, and 68.5%, respectively. The multivariate analysis showed that viable hepatocellular carcinoma, absence of maintenance therapy, non-responder, and PVT progression were significantly associated with liver-related events. The PVT progression was observed in 23.3% (56/240). The multivariate analysis identified older age, absence of maintenance therapy, and non-responder as independent factors associated with PVT progression. The multivariate analysis revealed that younger age, no hepatocellular carcinoma, presence of maintenance therapy, and lower Model for End-stage Liver Disease-Sodium score significantly contributed to 3-year survival. Of the 240 patients, 13 (8.9%) prematurely discontinued treatment due to any adverse events.

CONCLUSIONS

This study suggests that maintenance therapy, favorable response, and absence of PVT progression may suppress or control liver-related events in antithrombin III-based therapy for patients with PVT. Specifically, maintenance therapy could suppress not only liver-related events, but also PVT progression and improve the prognosis.

Antiplatelet Medications Are Associated With Bleeding and Decompensation Events Among Patients With Cirrhosis

BACKGROUND

In an aging population with cardiovascular comorbidities, anticoagulant (AC), antiplatelet (AP), and nonsteroidal anti-inflammatory drug (NSAID) use are increasing. It remains unclear whether these agents pose increased bleeding risk in cirrhosis. This study aimed to assess the association between these medications and bleeding and portal hypertension complications in cirrhosis.

METHODS

The IMS PharMetrics database was used to identify privately insured adults diagnosed with cirrhosis from 2007 to 2015, stratified as compensated or decompensated based on the presence of portal hypertensive complications 1 year before cirrhosis diagnosis. Bleeding or decompensation outcomes were assessed 6 to 18 months after cirrhosis diagnosis using a landmark analysis design. Multivariable Cox proportional hazards regression modeling assessed associations between AC, AP, and NSAID drug exposures and outcomes adjusting for covariates.

RESULTS

A total of 18,070 cirrhosis patients were analyzed; 57% male; 74% ages 50 to 64 years; 34% with a prior decompensation. Overall, 377 (2%) had claims for ACs; 385 (2%) APs; and 1231 (7%) NSAIDs. APs were associated with increased bleeding [adjusted hazard ratio (aHR)=1.31; 95% confidence interval (CI): 1.00, 1.72] and decompensation events (aHR=1.44; 95% CI: 1.06, 1.95) in a 9-month landmark analysis. NSAIDs were significantly associated with bleeding events (aHR=1.29; 95% CI: 1.06, 1.57) on 3-month landmark analysis. No statistically significant associations were seen between ACs and bleeding or decompensation outcomes in adjusted analyses.

CONCLUSIONS

AP use was associated with increased bleeding and decompensation events among privately insured patients with cirrhosis. NSAID use was associated with significant early bleeding, but not decompensations. Lastly ACs were not associated with bleeding or decompensation outcomes.

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.

Acquired bleeding disorders

Acquired bleeding disorders can accompany hematological, neoplastic, autoimmune, cardiovascular or liver diseases, but can sometimes also arise spontaneously. They can manifest as single factor deficiencies or as complex hemostatic abnormalities. This review addresses (a) acquired hemophilia A, an autoimmune disorder characterized by inhibitory autoantibodies against coagulation factor VIII; (b) acquired von Willebrand syndrome in patients with cardiovascular disorders, where shear stress abnormalities result in destruction of von Willebrand factor; and (c) liver function disorders that comprise complex changes in pro- and anti-hemostatic factors, whose clinical implications are often difficult to predict. The article provides an overview on the pathophysiology, diagnostic tests and state-of-the-art treatment strategies.

Cirrhosis and Coagulopathy: Mechanisms of Hemostasis Changes in Liver Failure and Their Management

Cirrhosis is an end-stage liver disease that can cause changes in any component of the hemostatic system. The net effects of the complicated hemostatic changes have long been unknown due to concurrent changes in pro-and antihemostatic drivers. Coagulation disorders are caused by various factors, including decreased clotting and inhibitor factor synthesis, reduced clearance of activated factors, quantitative and qualitative platelet defects, hyperfibrinolysis, and increased intravascular coagulation. This review discusses the pathogenesis of coagulopathy and multiple studies related to its clinical presentations. This article also highlights an additional problem in the diagnostic and therapeutic approach to this group of patients: the fact that traditional coagulation tests and transfusional strategies may not be reliable for assessing and managing bleeding or thrombotic risks. Hence, multiple management options have been assessed for bleeding and thrombosis in liver disease.

Nonmalignant portal vein thrombi in patients with cirrhosis consist of intimal fibrosis with or without a fibrin-rich thrombus

BACKGROUND AND AIM

Portal vein thrombosis (PVT) is a common complication of cirrhosis. The exact pathophysiology remains largely unknown, and treatment with anticoagulants does not lead to recanalization of the portal vein in all patients. A better insight into the structure and composition of portal vein thrombi may assist in developing strategies for the prevention and treatment of PVT.

APPROACH AND RESULTS

Sixteen prospectively and 63 retrospectively collected nonmalignant portal vein thrombi from patients with cirrhosis who underwent liver transplantation were included. Histology, immunohistochemistry, and scanning electron microscopy were used to assess structure and composition of the thrombi. Most recent CT scans were reanalyzed for thrombus characteristics. Clinical characteristics were related to histological and radiological findings. All samples showed a thickened, fibrotic tunica intima. Fibrin-rich thrombi were present on top of the fibrotic intima in 9/16 prospective cases and in 21/63 retrospective cases. A minority of the fibrotic areas stained focally positive for fibrin/fibrinogen (16% of cases), von Willebrand factor (VWF; 10%), and CD61 (platelets, 21%), while most of the fibrin-rich areas stained positive for those markers (fibrin/fibrinogen, 100%; VWF, 77%; CD61, 100%). No associations were found between clinical characteristics including estimated thrombus age and use of anticoagulants and presence of fibrin-rich thrombi.

CONCLUSION

We demonstrate that PVT in patients with cirrhosis consists of intimal fibrosis with an additional fibrin-rich thrombus in only one-third of cases. We hypothesize that our observations may explain why not all portal vein thrombi in patients with cirrhosis recanalize by anticoagulant therapy.

Liver status and outcomes in patients without previous known liver disease receiving anticoagulant therapy for venous thromboembolism

The association between elevated liver enzymes or FIB-4 (fibrosis index 4) and outcome in patients with venous thromboembolism (VTE) has not been evaluated. Data from patients in RIETE (Registro Informatizado Enfermedad TromboEmbólica) were used to assess the association between elevated liver enzymes or FIB-4 levels and the rates of major bleeding or death in apparent liver disease-free patients with acute VTE under anticoagulation therapy. A total of 6206 patients with acute VTE and without liver disease were included. Of them, 92 patients had major bleeding and 168 died under anticoagulation therapy. On multivariable analysis, patients with elevated liver enzymes were at increased mortality risk (HR: 1.58; 95% CI: 1.10-2.28), while those with FIB-4 levels > 2.67 points were at increased risk for major bleeding (HR: 1.69; 95% CI: 1.04-2.74). Evaluation of liver enzymes and FIB-4 index at baseline in liver disease-free patients with VTE may provide additional information on the risk for major bleeding or death during anticoagulation.

Management of Acute Coronary Syndrome in Patients with Liver Cirrhosis

Liver cirrhosis (LC) is becoming increasingly common among patients presenting with acute coronary syndromes (ACS) and is associated with significant cardiovascular morbidity and mortality. Management of such patients is complicated by LC related complications. Literature is scarce on the safety of antithrombotic regimens and invasive strategies for ACS in patients with LC, especially those undergoing liver transplant evaluation. Recently there has been evidence that cirrhosis is an independent risk factor for adverse outcomes in ACS. As patients with LC are generally excluded from large randomized trials, definitive guidelines for the management of ACS in this particular cohort are lacking. Many antithrombotic drugs require either hepatic activation or clearance; hence, an accurate assessment of hepatic function is required prior to initiation and dose adjustment. Despite a demonstrated survival benefit of optimal medical therapy and invasive revascularization techniques in LC patients with ACS, both strategies are currently underutilized in this population. This review aims to present currently available data and provide a practical, clinically oriented approach for the management of ACS in LC. Randomized clinical trials in LC patients with ACS are the need of the hour to further refine their management for favorable outcomes.

Ultrasonography in the diagnosis of complications in patients with portal hypertension

This review focuses on ultrasonography (US) to diagnose patients with complications in portal hypertension. Clinicians first use US to evaluate patients with suspected portal hypertension, because US is quick, simple, and radiation free. US is necessary for grading and performing paracentesis for ascites. Doppler US-based detection of reverse splanchnic vein flow or the presence of a spontaneous portosystemic shunt is highly specific in patients with cirrhosis. Since it is important to estimate spleen size in patients with portal hypertension, spleen size is usually measured by US. Spleen volume can be more accurately measured with 3D-US. Estimation of viable residual splenic volume after partial splenic embolization should be limited to cases with total splenic volume less than 1000 ml. Portal vein thrombosis is often detected during the US examination performed when symptoms first appear or during the follow-up. Two-dimensional transthoracic echocardiography is an excellent noninvasive screening test in patients with pulmonary portal hypertension who can undergo it. By measuring the maximum and minimum diastolic blood flow velocities in the renal arteries using renal color Doppler US, the pulsatility index (PI) and resistive index (RI) can be calculated. The PI and RI in cirrhotic patients were significantly higher than those in healthy subjects and patients with chronic hepatitis, and showed a significant positive correlation with the Child-Pugh Score. In conclusion, US is an essential tool for the diagnosis and treatment of patients with portal hypertension.

Association between Administration of Antithrombotics and Intraperitoneal Hemorrhage in Patients Undergoing Percutaneous Interventions for Liver Diseases

Currently, percutaneous interventions are essential for diagnosis and treatment of liver diseases. The most frequent complication of percutaneous interventions is intraperitoneal hemorrhage. Recently, the number of patients with liver diseases on antithrombotics has been increasing. This retrospective cohort study aimed to evaluate the risk factors for intraperitoneal hemorrhage in patients after percutaneous interventions for liver diseases. This study included 1025 patients who underwent percutaneous interventions for liver diseases from April 2015 to March 2020. All interventions were performed using an ultrasound-guided approach. The influence of antithrombotic drug administration in patients, who underwent percutaneous interventions according to the guidelines for the American Association for the Study of Liver Disease, was evaluated. Intraperitoneal hemorrhage after percutaneous interventions was detected by computed tomography. Intraperitoneal hemorrhage occurred in nine patients (0.88%); however, these adverse events were not severe. We compared clinical characteristics between the patients with and without intraperitoneal hemorrhage. Although, there was no difference based on the administration of antithrombotics (p = 0.1961), seven of nine patients who showed intraperitoneal hemorrhage received percutaneous treatments (radio frequency ablation or microwave ablation). Therefore, we divided patients who underwent treatments and liver biopsy and then investigated the influence of antithrombotics on the intraperitoneal hemorrhage. After propensity score matching in each patient group, the administration of antithrombotics was not identified as a risk factor for hemorrhage in patients who underwent interventional treatments and patients who underwent liver biopsy. When the antithrombotics were discontinued, according to the guidelines, it may not increase the risk factor for hemorrhage in patients of liver disease who underwent percutaneous interventions.

Targeting von Willebrand factor in liver diseases: A novel therapeutic strategy?

Acute and chronic liver disease are associated with substantial alterations in the hemostatic system. Evidence from both experimental and clinical studies suggests that anticoagulants slow the progression of liver disease. Efficacy of those anticoagulant drugs is, in part, attributed to a reduction of microthrombi formation within the liver. Although anticoagulant drugs show promising results, bleeding risk associated with these drugs is an obvious drawback, particularly in patients with a complex coagulopathy driven by decreased liver function. Identifying therapies that reduce intrahepatic thrombosis with minimal bleeding risk would significantly advance the field. Among the hemostatic alterations observed in patients are substantially increased levels of the platelet-adhesive protein von Willebrand factor (VWF). In contrast, levels of A Disintegrin and Metalloproteinase with Thrombospondin motifs, the enzyme that regulates VWF activity, are significantly reduced in patients with liver disease. Highly elevated VWF levels are proposed to accelerate intrahepatic thrombus formation and thus be a driver of disease progression. Strong clinical evidence suggesting a link between liver disease and changes in VWF is now being matched by emerging mechanistic data showing a detrimental role for VWF in the progression of liver disease. This review focuses on clinical and experimental evidence supporting a connection between VWF function and the progression of acute and chronic liver diseases. Furthermore, with the recent anticipated approval of several novel therapies targeting VWF, we discuss potential strategies and benefits of targeting VWF as an innovative therapy for patients with liver disease.

Treatment of portal vein thrombosis: an updated narrative review

Portal vein thrombosis (PVT) is the most frequent among the splanchnic vein thrombosis, accounting for 90% of cases. More than half of PVT are provoked by liver cirrhosis, solid cancer or myeloproliferative neoplasms. The remaining cases are non-malignant non-cirrhotic PVT and include either unprovoked events or thrombosis secondary to other less common risk factors (e.g. abdominal surgery, intrabdominal inflammations/infections, or hormonal stimuli). Anticoagulant therapy in patients with acute symptomatic PVT should be started early after diagnosis, if no active bleeding, to obtain greater vessel recanalization and reduce the occurrence of portal-hypertension related complications. Gastroesophageal varices do not represent a contraindication to anticoagulant treatment, as long as adequate measures have been undertaken for the prophylaxis of gastroesophageal bleeding. Different treatment options (unfractionated or low molecular weight heparin, vitamin K antagonists and direct oral anticoagulants [DOACs]) can be considered. In this narrative review we will discuss the treatment of PVT in the three most common scenarios (cirrhosis-associated, cancer-associated and non-malignant non-cirrhotic PVT). We will also discuss the role of the DOACs and summarise recent guidelines on this topic.

Non-alcoholic fatty liver disease - a procoagulant condition?

Non-alcoholic fatty liver disease (NAFLD) is associated with a number of extrahepatic comorbidities and considerable cardiovascular morbidity and mortality, which is possibly related to coagulation changes associated with metabolic syndrome. Coagulation disorders are common in patients with liver disease of any etiology, and here we review possible alterations in coagulation cascade specific to NAFLD. We discuss derangements in the coagulation cascade and fibrinolysis, endothelial dysfunction, and platelet abnormalities as possible culprits for altered coagulation and explore the significance of these changes for potential treatment targets.

Prediction of portal vein thrombosis after hepatectomy for hepatocellular carcinoma

PURPOSE

Portal vein thrombosis (PVT) following hepatectomy is potentially life-threatening. We aimed to evaluate the incidence of PVT after hepatectomy for hepatocellular carcinoma and identify coagulation and fibrinolytic factors that could predict early-stage postoperative PVT.

METHODS

A retrospective analysis was conducted on 65 hepatocellular carcinoma patients who underwent radical hepatectomy. The risk factors for postoperative PVT were identified based on univariate and multivariate analyses, and the levels of coagulation and fibrinolytic factors were measured during the perioperative period.

RESULTS

The incidence of PVT after hepatectomy was 20.0%. The patients were divided into two groups: those with PVT (n=13; PVT group) and those without PVT (n=52; no-PVT group). The frequency of the use of the Pringle maneuver during surgery was higher in the PVT group than in the no-PVT group, and the postoperative/preoperative ratios of thrombin-antithrombin III complex (TAT) and of D-dimer were significantly higher in the PVT group.

CONCLUSION

A high incidence of PVT was found in hepatocellular carcinoma patients after hepatectomy. The frequency of the Pringle maneuver is a potential risk factor for postoperative PVT, and the postoperative/preoperative TAT and D-dimer ratios may be used as early predictors of PVT after hepatectomy for hepatocellular carcinoma.

Intraoperative Type I Acute Myocardial Infarction During Liver Transplant Requiring Intra-Aortic Balloon Pump: A Case Report

We describe a complex case of liver transplant in a 70-year-old male patient with no known history of coronary artery disease, normal preoperative left ventricular function, and negative preoperative cardiac workup who developed progressive intra-operative left ventricular myocardial dysfunction secondary to class I acute myocardial infarction, ultimately requiring intraoperative intra-aortic balloon pump insertion to optimize myocardial perfusion. Management of myocardial ischemia was complicated by bleeding in the setting of coagulopathy necessitating correction. Once hemostasis was achieved, the patient immediately underwent coronary angiography and bare metal stent placement in the mid-left anterior descending coronary artery for an acute plaque rupture.

Pharmacokinetic/Pharmacodynamic Modelling and Simulation of Lusutrombopag, a Novel Thrombopoietin Receptor Agonist, for the Treatment of Thrombocytopenia in Patients with Chronic Liver Disease Undergoing Invasive Procedures

BACKGROUND

Patients with thrombocytopenia associated with chronic liver disease (CLD) are at greater risk of bleeding during invasive procedures. This study characterized the pharmacokinetic/pharmacodynamic (PK/PD) profile of lusutrombopag, a novel thrombopoietin-receptor agonist, using modelling and simulation, and evaluated the appropriate dose regimen for treatment of thrombocytopenia in CLD patients undergoing invasive procedures.

METHODS

A population PK/PD model was developed using plasma lusutrombopag concentrations from 78 healthy subjects and 349 CLD patients, as well as platelet counts from 347 of these 349 patients. Covariates were explored from subject characteristics. Monte-Carlo simulations were performed to assess a dose response for efficacy (platelet counts ≥ 50,000/μL) and a risk for platelet overshooting (platelet counts > 200,000/μL).

RESULTS

Visual predictive checks indicated the developed models described the PK/PD profile of lusutrombopag well. In the simulations, without stopping criteria, lusutrombopag 3 mg once daily for 7 days before scheduled invasive procedures provided effective platelet response (85.2% probability for efficacy). The probability of platelet overshooting was 1.2%, indicating that platelet monitoring is not necessary. Although body weight was an influential covariate on the pharmacokinetics of lusutrombopag, individually estimated peak platelet counts overlapped among the body weight groups, suggesting no clinically significant effect on body weight.

CONCLUSION

The modelling and simulation support lusutrombopag 3 mg once daily for 7 days without platelet monitoring.

Thrombin Generation and Cirrhosis: State of the Art and Perspectives

Epidemiological and laboratory studies performed in the last decades have changed our understanding of coagulopathy in cirrhosis, from a condition at increased risk of hemorrhagic events to one at higher thrombotic risk. However, it is not clear whether the decrease in factors that promote (except factor [F] VIII) versus inhibit coagulation in patients with cirrhosis results in a rebalanced state or in a hypercoagulable phenotype. This issue can be partially addressed using thrombin generation assays (TGA), which unlike routine clotting tests (prothrombin time or activated partial thromboplastin time) are sensitive to both procoagulant factors and coagulation inhibitors. However, many preanalytical issues and variable analytical methodologies used in TGAs complicate data analysis and interlaboratory comparisons. The introduction of TGAs in which activators of the protein C pathway (particularly soluble forms of thrombomodulin [TM]) are added has allowed detection of a reduced anticoagulant effect of TM or even a hypercoagulable phenotype as judged by endogenous thrombin potential. However, inter- and intra-assay variability may be greater with this TGA variant compared with "standard" TGAs. TGAs also allowed identifying main determinants of the hypercoagulability phenotype in the presence of TM: acquired antithrombin and protein C deficiencies, and elevated FVIII levels. The aim of this narrative review is to summarize the preanalytical and methodological variables of TGAs and also the findings of the main studies that have evaluated TGAs in patients with cirrhosis. The review also provides some propositions for future studies and outlines some perspectives on the potential implementation of this promising tool in clinical practice for the study of coagulation in patients with cirrhosis.

In Vitro Evaluation of Pro- and Anticoagulant Drugs in Children with End-Stage Liver Disease Undergoing Liver Transplantation

Background Pro- and anticoagulant drugs are commonly used in pediatric liver transplantation to prevent and treat thrombotic and bleeding complications. However, the combination of baseline hemostatic changes in children with liver disease and additional changes induced by transplantation makes this very challenging. This study aimed to analyze the efficacy of clinically available pro- and anticoagulant drugs in plasma from children undergoing liver transplantation.

Methods In vitro effects of pro- and anticoagulant drugs on thrombin generation capacity were tested in plasma samples of 20 children (≤ 16 years) with end-stage liver disease undergoing liver transplantation, and compared with 30 age-matched healthy controls.

Results Addition of pooled normal plasma had no effect in patients or controls, while 4-factor prothrombin complex concentrate increased thrombin generation in both patients and controls, with enhanced activity in patients. At start of transplantation, dabigatran and unfractionated heparin had a higher anticoagulant potency in patients, whereas 30 days after transplantation low molecular weight heparin was slightly less effective in patients. Effects of rivaroxaban were comparable between patients and controls.

Conclusion This study revealed important differences in efficacy of commonly used pro- and anticoagulant drugs in children with end-stage liver disease undergoing liver transplantation. Therefore, dose adjustments of these drugs may be required. The results of this study may be helpful in the development of urgently needed protocols for strategies to prevent and treat bleeding and thrombotic complications in pediatric liver transplantation.

Acquired bleeding disorders

Acquired bleeding disorders can accompany hematological, neoplastic, autoimmune, cardiovascular or liver diseases, but can sometimes also arise spontaneously. They can manifest as single factor deficiencies or as complex hemostatic abnormalities. This review addresses (a) acquired hemophilia A, an autoimmune disorder characterized by inhibitory autoantibodies against coagulation factor VIII; (b) acquired von Willebrand syndrome in patients with cardiovascular disorders, where shear stress abnormalities result in destruction of von Willebrand factor; and (c) liver function disorders that comprise complex changes in pro- and anti-hemostatic factors, whose clinical implications are often difficult to predict. The article provides an overview on the pathophysiology, diagnostic tests and state-of-the-art treatment strategies.

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.

Acute Portal Vein Thrombosis Treated with Recombinant Human Soluble Thrombomodulin Combined with Antithrombin III

Portal vein thrombosis is a major complication associated with liver cirrhosis. In cirrhotic patients, a decrease in procoagulant and anticoagulant factors and an unstable balance between them is observed, and a relative decrease in the activation of anticoagulant drivers is one of the main causes of portal vein thrombosis (PVT). Herein, we report a case of acute portal thrombosis associated with liver cirrhosis and treated with a recombinant form of soluble thrombomodulin (thrombomodulin alpha, TM-α) in combination with antithrombin III. TM-α was administered in accordance with the dosage and route of administration for disseminated intravascular coagulation therapy and resulted in dissolution of PVT with a gradual decrease in D-dimer levels. No adverse events were observed during the course of treatment. In the future, in addition to conventional anticoagulation therapy using heparin or antivitamin K drugs, novel therapies targeting protein C activation using a recombinant form of soluble thrombomodulin may play an important role in the treatment of acute PVT.

Perioperative management of antithrombotic treatment

End-stage liver disease is characterized by multiple and complex alterations of hemostasis that are associated with an increased risk of both bleeding and thrombosis. Liver transplantation further challenges the feeble hemostatic balance of patients with decompensated cirrhosis, and the management of antithrombotic treatment during and after transplant surgery, which is particularly difficult. Bleeding was traditionally considered the major concern during and early after surgery, but it is increasingly recognized that transplant recipients may also develop thrombotic complications. Pathophysiology of hemostatic complications during and after transplantation is multifactorial and includes pre-, intra-, and postoperative risk factors. Risk stratification is important, as it helps the identification of high-risk recipients in whom antithrombotic prophylaxis should be considered. In recipients who develop thrombosis during or after surgery, prompt treatment is indicated to prevent graft failure, retransplantation, and death.

Cirrhosis, Thrombosis, Finding FaXts about Doses: Dosing of Unfractionated Heparin for Venous Thromboembolism in Cirrhosis

Background: Despite known disease-specific alterations to anti–factor Xa (AXA) levels, the physiological response of patients with cirrhosis to unfractionated heparin (UFH) infusions is not well established in clinical settings. Objective: The purpose of this study was to characterize the dosing and safety profile of UFH in patients with varying degrees of cirrhosis when treated for venous thromboembolism (VTE). Methods: This retrospective observational study was conducted at a single academic medical center in the United States. Patients with a diagnosis of cirrhosis who received UFH infusions for greater than 48 hours for treatment of VTE were included. Comparisons between heparin infusion rates, AXA levels, and safety outcomes based on severity of cirrhosis were made to define differences between those groups. Results: When compared by compensation status or by Child-Turcotte-Pugh (CTP) class, patients with more severe disease trended toward lower initial AXA levels on heparin initiation and higher heparin requirements to achieve therapeutic levels and were significantly less likely to achieve therapeutic levels than patients with less severe disease ( P = 0.001 for compensation, P = 0.017 for CTP). Additionally, bleeding rates were higher in patients with more severe disease, without reaching statistical significance. Conclusion and Relevance: Patients with severe cirrhosis required higher doses of heparin to achieve the same therapeutic AXA levels, but also tended to have higher rates of bleeding compared with less severe cirrhosis. These results represent further evidence of changes in heparin response as cirrhosis severity increases and may suggest that current monitoring methods are suboptimal in this patient population.

A Diagnostic Prediction Model of Acute Symptomatic Portal Vein Thrombosis

BACKGROUND

The aim of this study was to develop a diagnostic prediction model to improve identification of acute symptomatic portal vein thrombosis (PVT).

METHODS

We examined 47 patients with PVT and 94 controls without PVT in the Second Affiliated Hospital of Soochow University and Suqian People's Hospital of Nanjing, Gulou Hospital Group. We constructed a prediction model by using a support vector machine (SVM) classifier coupled with a least absolute shrinkage and selection operator (LASSO). We applied a 10-fold cross-validation to estimate the error rate for each model.

RESULTS

The present study indicated that acute symptomatic PVT was associated with 11 indicators, including liver cirrhosis, D-Dimer, splenomegaly, splenectomy, inherited thrombophilia, ascetic fluid, history of abdominal surgery, bloating, C-reactive protein (CRP), albumin, and abdominal tenderness. The LASSO-SVM model achieved a sensitivity of 91.5% and a specificity of 100.0%.

CONCLUSIONS

We developed a LASSO-SVM model to diagnose PVT. We demonstrated that the model achieved a sensitivity of 91.5% and a specificity of 100.0%.

Anticoagulation in Patients with Liver Cirrhosis (Literature Review)

Liver cirrhosis is accompanied by complex hemostatic disorders with an increase in the risk of both hemorrhagic and thrombotic complications. Reduced coagulation protein synthesis, such as factors II, VII, IX, X and thrombocytopenia are associated with an increased risk of bleeding. Reducing the synthesis of such anticoagulants as protein C, protein S, antithrombin III is accompanied by increased generation of thrombin, which leads to procoagulant status, increased risk of venous thrombosis, pulmonary embolism, and portal vein thrombosis. Activation of the coagulation cascade increases the risk of thrombosis, and also plays an important role in liver damage, contributing to the progression of fibrosis. Cirrhosis increases the risk of thromboembolic complications of atrial fibrillation.

Anticoagulants are necessary for the prevention of thrombosis and thromboembolic complications. However, there are no large prospective studies. There is insufficient data on the safety of anticoagulant therapy in cirrhosis. There are difficulties in monitoring anticoagulation in the application of vitamin K antagonists and low molecular weight heparins.

The review presents the available data on the use of warfarin, unfractionated heparin, low molecular weight heparins and direct oral anticoagulants in patients with liver cirrhosis, indicating the need for prevention of venous thrombosis in patients with risk factors, the possibility of preventing decompensation of cirrhosis, reducing the frequency of cardioembolic strokes in patients with atrial fibrillation.

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.

Hypercoagulability in End-stage Liver Disease: Review of Epidemiology, Etiology, and Management

In this review, we analyze the epidemiology of thromboses related to end-stage liver disease (ESLD), discuss causes of hypercoagulability, describe susceptible populations, and critically evaluate proposed prophylaxis and treatment of thromboses. Classically, ESLD has been regarded as a model for coagulopathy, and patients were deemed to be at high risk for bleeding complications. Patients with ESLD are not auto-anticoagulated, and they do not have a lower risk of portal vein thrombosis, intracardiac thrombus formation, pulmonary embolism or hepatic artery thrombosis. Though the cause of hypercoagulability is multifactorial, endothelial dysfunction likely plays a central role for all patients with ESLD. Some subpopulations, such as patients with nonalcoholic steatohepatitis and autoimmune conditions, are at increased risk of thrombotic events as are patients of Hispanic ethnicity. The science behind prophylaxis of different types of clotting and treatment of thromboses is developing rapidly. A number of medications, including low molecular weight heparin, unfractionated heparin, aspirin, vitamin K antagonists, and direct oral anticoagulants can be used, but clear guidelines are lacking. Acute intraoperative clotting can be associated with high mortality. Routine use of transesophageal echocardiography can be helpful in early recognition and treatment of intraoperative thrombosis. Heparin should be reserved for cases of intracardiac thrombus/pulmonary embolism without hemodynamic instability. In unstable patients, low dose of recombinant tissue plasminogen activator can be used. In this new era of heightened awareness of thrombotic events in ESLD patients, prospective randomized trials are urgently needed to best guide clinical practice.

Anticoagulant therapy in patients with liver cirrhosis and portal vein thrombosis: insights for the clinician

Portal vein thrombosis (PVT) is a frequent complication in the natural history of patients with liver cirrhosis (LC). The prevalence of PVT in LC is highly variable, ranging from 0.6% to 25% according to different reports. The impact of PVT on the natural history of LC is unclear, but it seems to negatively affect the prognosis of patients undergoing liver transplantation (LT) by increasing post-LT mortality and delaying waiting time. The antithrombotic treatment of PVT is still challenging as PVT may often remain asymptomatic and incidentally diagnosed, and a spontaneous partial/total regression of PVT is observed in an important proportion of patients, even in the absence of anticoagulation. Recent evidence suggested that the anticoagulant treatment for PVT may favorably affect both ischemic and bleeding outcomes in LC patients. Anticoagulant therapies so far available include unfractioned heparin, low molecular weight heparins (LMWHs) and fondaparinux for acute treatment, and LMWHs and vitamin K antagonists (VKAs) for long-term treatment. No robust data currently support the use of direct oral anticoagulants (DOACs) in patients with LC and PVT, as the safety and efficacy of DOACs in this setting is still unclear. This review summarizes current evidence for the evaluation and management of patients with LC and PVT.

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.

Efficacy and safety of edoxaban for treatment of portal vein thrombosis following danaparoid sodium in patients with liver cirrhosis

AIM

To compare the efficacy and safety of edoxaban and warfarin for treatment of portal vein thrombosis (PVT) following danaparoid sodium in patients with liver cirrhosis.

METHODS

Fifty cirrhotic patients with PVT treated initially for 2 weeks with danaparoid sodium were enrolled in this retrospective cohort study. Treatment was later switched to either edoxaban (n = 20) or warfarin (n = 30). We compared the efficacy and safety of edoxaban and warfarin for up to 6 months. The PVT volume was measured by dynamic computed tomography before treatment, at 2 weeks, and at 1, 3, and 6 months.

RESULTS

There were no significant differences in the clinical characteristics of patients in the two groups. Treatment with edoxaban reduced the volume of PVT from 1.42 cm³ at 2 weeks to 0.42 cm³ at 6 months, and prevented exacerbation of PVT at 6 months after treatment with danaparoid sodium (P = 0.016). In contrast, treatment with warfarin resulted in increased PVT volume from 1.73 cm³ at 2 weeks to 2.85 cm³ at 6 months, despite the control of the international normalized ratio in 57% of the patients (P = 0.005). Multivariate regression analysis identified edoxaban therapy as the single significant and independent determinant of PVT reduction at 6 months (P = 0.0014, hazard ratio 6.400). Clinically significant gastrointestinal bleeding was encountered in 3 of 20 (15%) patients of the edoxaban group and 2 of 30 (7%) of the warfarin group (P = 0.335).

CONCLUSION

Edoxaban following danaparoid sodium is an effective anticoagulant and could be potentially considered as one of the treatment options for PVT in cirrhotic patients.

Pathogenesis, prevention, and management of bleeding and thrombosis in patients with liver diseases

Patients with liver diseases may develop alterations in all components of the hemostatic system. Thrombocytopenia, low levels of coagulation factors and inhibitors, low levels of fibrinolytic proteins, and increased levels of endothelial-derived proteins such as von Willebrand factor are all part of the coagulopathy of liver disease. Due to concomitant changes in pro- and antihemostatic drivers, the net effects of these complex hemostatic changes have long been unclear. According to current concepts, the hemostatic system of patients with liver disease is in an unstable balance, which explains the occurrence of both bleeding and thrombotic complications. This review will discuss etiology and management of bleeding and thrombosis in liver disease and will outline unsolved clinical questions. In addition, we will discuss the role of intrahepatic activation of coagulation for progression of liver disease, a novel paradigm with potential consequences for the general management of patients with liver disease.