Treatment of direct oral anticoagulants in patients with liver cirrhosis and portal vein thrombosis

The current findings on the gut-liver axis and the molecular basis of NAFLD/NASH associated with gut microbiome dysbiosis

Recent research has highlighted the complex relationship between gut microbiota, metabolic pathways, and nonalcoholic fatty liver disease (NAFLD) progression. Gut dysbiosis, commonly observed in NAFLD patients, impairs intestinal permeability, leading to the translocation of bacterial products like lipopolysaccharides, short-chain fatty acids, and ethanol to the liver. These microbiome-associated mechanisms contribute to intestinal and hepatic inflammation, potentially advancing NAFLD to NASH. Dietary habits, particularly those rich in saturated fats and fructose, can modify the microbiome composition, leading to dysbiosis and fatty liver development. Metabolomic approaches have identified unique profiles in NASH patients, with specific metabolites like ethanol linked to disease progression. While bariatric surgery has shown promise in preventing NAFLD progression, the role of gut microbiome and metabolites in this improvement remains to be proven. Understanding these microbiome-related pathways may provide new diagnostic and therapeutic targets for NAFLD and NASH. A comprehensive review of current literature was conducted using multiple medical research databases, including PubMed, Scopus, Web of Science, Embase, Cochrane Library, ClinicalTrials.gov, ScienceDirect, Medline, ProQuest, and Google Scholar. The review focused on studies that examine the relationship between gut microbiota composition, metabolic pathways, and NAFLD progression. Key areas of interest included microbial dysbiosis, endotoxin production, and the influence of diet on gut microbiota. The analysis revealed that gut dysbiosis contributes to NAFLD through several mechanisms, diet significantly influences gut microbiota composition, which in turn affects liver function through the gut-liver axis. High-fat diets can lead to dysbiosis, altering microbial metabolic activities and promoting liver inflammation. Specifically, gut microbiota-mediated generation of saturated fatty acids, such as palmitic acid, can activate liver macrophages and increase TNF-α expression, contributing to NASH development. Different dietary components, including cholesterol, fiber, fat, and carbohydrates, can modulate the gut microbiome and influence NAFLD progression. This gut-liver axis plays a crucial role in maintaining immune homeostasis, with the liver responding to gut-derived bacteria by activating innate and adaptive immune responses. Microbial metabolites, such as bile acids, tryptophan catabolites, and branched-chain amino acids, regulate adipose tissue and intestinal homeostasis, contributing to NASH pathogenesis. Additionally, the microbiome of NASH patients shows an elevated capacity for alcohol production, suggesting similarities between alcoholic steatohepatitis and NASH. These findings indicate that targeting the gut microbiota may be a promising approach for NASH treatment and prevention. Recent research highlights the potential of targeting gut microbiota for managing nonalcoholic fatty liver disease (NAFLD). The gut-liver axis plays a crucial role in NAFLD pathophysiology, with dysbiosis contributing to disease progression. Various therapeutic approaches aimed at modulating gut microbiota have shown promise, including probiotics, prebiotics, synbiotics, fecal microbiota transplantation, and dietary interventions. Probiotics have demonstrated efficacy in human randomized controlled trials, while other interventions require further investigation in clinical settings. These microbiota-targeted therapies may improve NAFLD outcomes through multiple mechanisms, such as reducing inflammation and enhancing metabolic function. Although lifestyle modifications remain the primary recommendation for NAFLD management, microbiota-focused interventions offer a promising alternative for patients struggling to achieve weight loss targets.

Experience With Dabigatran on Rate of Portal Vein Thrombosis Recanalization, Disease Progression and Survival

BACKGROUND AND AIMS

We assessed clinical, procoagulant and genetic risk factors and clinical outcomes in dabigatran-treated patients with non-tumoural acute and acute-on-chronic portal vein thrombosis (PVT).

METHODS

Patients with a new diagnosis of non-tumoural acute and acute-on-chronic PVT between January 2021 and January 2024 (aged ≥ 18 years) in those without/with cirrhosis (Child-Pugh (CP)-A/B/C ≤ 10) were started on dabigatran and followed and compared with those on vitamin K antagonist (VKA) and untreated individuals.

RESULTS

Dabigatran was prescribed in 119 patients with PVT type 1 (61, 51.3%), type 2 (34, 28.6%), type 3 (24, 20.2%); 72 (60.5%) with cirrhosis [CP-A (27, 37.5%), CP-B (43, 59.7%) and CP-C10 (2, 2.8%)]. Procoagulant factors noted were JAK2V617F (10.1%), CALR (2.5%) and factor V Leiden (1.6%) mutations, antiphospholipid syndrome (APS, 15.2%), isolated Protein C (14.3%) and Protein S (16.8%) deficiency.

COMPARATORS

28 patients who declined anticoagulation/were unable to come for follow-up, and six with CP-C received VKA. Overall recanalization rate (RR) on dabigatran was 56 (47.1%); 25 (21%) complete recanalization, 31 (26%) partial recanalization and 63 (52.9%) stable PVT over median follow-up of 32 months. Patients not anticoagulated had a spontaneous RR in 21.4% (28 patients; p = 0.005 compared with dabigatran group) and none recanalized on VKA. On multivariable analysis, predictors of recanalization on dabigatran were Factor VIII Antigen level (FVIII:Ag, HR 0.6; 95% CI 0.3-0.9, p = 0.032), non-occlusive PVT (HR 3.5, 95% CI 1.9-5.6, p = 0.025) and acute PVT (HR 2.1; 95% CI 1.5-3.2, p = 0.003). Mortality was 14 (11.8%).

CONCLUSION

On dabigatran, 47% of 119 patients achieved portal vein recanalization over 32 months of follow-up which was higher than the spontaneous RR (21.4%) in an untreated cohort. High Factor VIII:Ag was a predictor of non-recanalization. Dabigatran was safe in cirrhosis (CP-A and B) while further work is needed in CP-C.

Analysis of Related Influencing Factors of Portal Vein Thrombosis After Hepatectomy

Purpose: To analyze the related factors of portal vein thrombosis (PVT) after hepatectomy. Methods: A retrospective analysis was made on 1029 patients who underwent partial hepatectomy in the first affiliated Hospital of Chongqing Medical University from March 2018 to March 2023, including PVT group (n = 24) and non-PVT group (n = 1005). The general and clinical data of the two groups were collected. Univariate and multivariate logistic regression analysis was used to analyze the clinical information of the two groups. Result: The proportion of preoperative hepatitis B, liver cirrhosis, ascites, intraoperative blood transfusion, postoperative hemostatic drugs, preoperative prothrombin time, intraoperative portal occlusion time, operation time, international standardized ratio of prothrombin time on the first day after operation, D-dimer on the first day after operation, fibrin degradation products on the first day after operation and postoperative hospital stay in the PVT group were all higher than those in the control group (P < .05). The preoperative platelet and albumin in the PVT group were lower than those in the control group. Intraoperative blood transfusion, liver cirrhosis, ascites, international standardized ratio of postoperative prothrombin time, postoperative fibrin degradation products, hilar occlusion time and albumin were independent risk factors for PVT. Conclusion: There are many influencing factors of PVT after hepatectomy. Clinical intervention should be taken to reduce PVT. Clinical Registration Number: K2023-348.

Direct Oral Anticoagulants Versus Traditional Anticoagulation in Cirrhotic Patients with Portal Vein Thrombosis: Updated Systematic Review

BACKGROUND

This systematic review aimed to evaluate the comparative effectiveness and safety of direct oral anticoagulants (DOACs) compared to traditional anticoagulation (vitamin K antagonists or low-molecular-weight heparins) in cirrhotic patients with portal vein thrombosis (PVT).

METHODS

We conducted a literature search in PubMed and Embase databases up to May 2024. Studies were selected according to the PICOS criteria, focusing on cirrhotic patients with PVT treated with DOACs (dabigatran, rivaroxaban, apixaban, or edoxaban) compared to traditional anticoagulation.

RESULTS

Our systematic review included four observational studies conducted in Japan, China, and the United States, involving a total of 223 patients with cirrhosis and PVT. The included studies collectively suggested that anticoagulation therapy, including DOACs, was associated with improved recanalization rates and reduced progression of PVT in patients with liver cirrhosis, without a significant increase in bleeding complications. Specifically, edoxaban demonstrated superior effectiveness in reducing PVT volume compared to traditional anticoagulation, while maintaining a favorable safety profile.

CONCLUSION

DOACs may provide a promising therapeutic option for PVT in cirrhotic patients. Further research is needed to confirm the potential benefits and risks of DOACs in this population.

Comparison of the Efficacy and Safety of Direct Oral Anticoagulants and Warfarin in Cirrhotic Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

Currently, there is limited evidence regarding the use of direct oral anticoagulants (DOACs) for patients with liver cirrhosis (LC). We performed a meta-analysis to compare the efficacy and safety of DOACs versus warfarin in this population.

METHODS

We searched PubMed, Cochrane Library, Web of Science, Embase and Scopus databases from inception to August 2024. Clinical studies comparing the use of DOACs with warfarin in cirrhotic patients were included. Hazard ratios (HRs) with 95% CIs were estimated by either fixed or random effects models. Primary efficacy outcomes were ischemic stroke/thromboembolism (IS/TE) and all-cause death, the primary safety outcomes were the bleeding risks.

RESULTS

Sixteen studies were included (16 829 individuals). DOACs had similar benefits in preventing IS/TE (HR = 0.87, 95% CI: 0.69-1.10), but DOACs were significantly associated with reduced risk of all-cause death (HR = 0.87, 95% CI: 0.79-0.97). On the other hand, we observed significantly reduced risks of any bleeding (HR = 0.60; 95%CI: 0.37-0.95), major bleeding (HR = 0.72; 95%CI: 0.63-0.82), intracranial hemorrhage (ICH) (HR = 0.47; 95%CI: 0.30-0.73), and gastrointestinal bleeding (GIB) (HR = 0.72, 95% CI: 0.60-0.87) in patients receiving DOACs. Results were consistent in cirrhotic patients with AF. Furthermore, DOACs reduced the incidence of major bleeding (HR = 0.65, 95%CI: 0.55-0.78) and ICH (HR = 0.17, 95%CI: 0.04-0.76) in patients with moderate to severe cirrhosis.

CONCLUSION

Our study demonstrates that DOACs, compared with warfarin, exerted comparable efficacy and better safety and may represent a safer alternative to warfarin in cirrhotic patients.

Portal Vein Variations, Clinical Correlation, and Embryological Explanation: A Review Article

Portal vein (PV) is a large vein that collects blood from the abdominal part of gall bladder, pancreas, alimentary tract, and spleen and transports to the liver. One of the parts of the extraembryonic venous system, the vitelline veins, is where PV starts. In about five weeks of gestation, a venous plexus is formed, and variations in this plexus lead to portal variance. The junction of superior mesenteric and splenic veins is typically where the vein begins to network. There are five types of branching patterns of the right PV: conventional branching, trifurcation branching, early branching, separate segment 7 branching, and separate segment 6 branching. To perform pancreatic, duodenal, and liver surgeries, knowledge of variations in PV formation is important. For surgical and interventional operations to be accurate, it is crucial to understand the architecture of the PV and its anomalies. As distinct regions of the brain connect with one another, portal architecture is frequently observed in imaging investigations. Portal hypertension is characterized as an increase in blood pressure in the portal venous system (PVS) in the context of severe liver disease, such as cirrhosis. Non-invasive methods for examining the anatomy and anomalies of the PV include ultrasound, computed tomography (CT), and magnetic resonance (MR). There are many abnormalities of PVS that have been discussed in the articles such as Congenital PV Absence; PV Branches Congenitally Grow in Structure; Hypoplasia, Atresia, and Stenosis of the PV; and Portosystemic Shunts.

Direct oral anticoagulants (DOACs): From the laboratory point of view

Direct oral anticoagulants (DOACs) represent a new generation of drugs that have been increasingly used in the prevention and treatment of thromboembolic states. According to the mechanism of anticoagulant action, DOACs are divided into two groups: direct inhibitors of thrombin (dabigatran) and direct inhibitors of activated factor X (FXa) (rivaroxaban, apixaban, edoxaban, betrixaban). Compared to the vitamin K antagonists, DOACs are superior in terms of onset of action, pharmacokinetic and pharmacodynamics properties and fixed daily dose without the need for routine coagulation monitoring. Despite these advantages, there are clinical conditions in which laboratory measurement of DOACs should be performed. Although DOACs have an impact on screening haemostasis assays (prothrombin time, PT; activated partial thromboplastin time, aPTT; and thrombin time, TT), these tests are not appropriate for quantifying drug levels. Therefore, specific quantitative methods (LC-MS/MS as a gold standard method for all DOACs, coagulometric and chromogenic assays for dabigatran, and chromogenic anti-Xa assays with drug-specific calibrators for inhibitors of FXa) should only be used for determination of DOACs concentration. The aim of this review is to present all aspects of laboratory assessment of DOACs, including pre-analytical, analytical and post-analytical factors in the overall testing process with a special accent on the available specific quantitative methods for measurement of DOACs in circulation.