Pathophysiology and management of bleeding and thrombosis in patients with liver disease

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.

[Coagulation disorders in liver cirrhosis - Diagnostics and management]

Patients with liver cirrhosis often exhibit complex alterations in their hemostatic system that can be associated with both bleeding and thrombotic complications. While prophylactic correction of abnormal coagulation parameters should be avoided, an individualized approach is recommended prior to invasive procedures, whereby specific preventive measures to stabilize hemostasis should be based on the periprocedural bleeding risk. While the haemostatic system of patients with compensated cirrhosis is often in a rebalanced haemostatic state due to a parallel decline in both pro- and anti-haemostatic factors, a decompensation of liver cirrhosis can lead to destabilization of this fragile equilibrium. Since conventional coagulation tests do not adequately capture the complex changes in the hemostatic system in cirrhosis, functional analysis methods such as viscoelastic tests or thrombin generation assays can be used for evaluating the coagulation status. This review describes the underlying pathophysiological changes in the hemostatic system in liver cirrhosis, provides an overview of diagnostic methods and discusses therapeutic measures in case of bleeding and thrombotic complications.

Acquired bleeding disorders

Acquired bleeding disorders can develop in previously healthy people irrespective of age or gender but are particularly common in patients with certain underlying conditions. Here, we review recent advances in the management of acquired haemophilia A (AHA), acquired von Willebrand syndrome (AVWS), and patients with hemostatic abnormalities due to chronic liver disease (CLD). Patients with AHA can now benefit from prophylaxis with emicizumab, a therapeutic antibody that mimics the function of activated coagulation factor VIII. The treatment of AVWS remains challenging in many situations and requires careful consideration of the underlying condition. Haemostatic abnormalities in CLD are often compensated by proportional reduction in pro and anti-haemostatic factors resulting in sustained or even increased thrombin generation. Consequently, bleeding in CLD is rarely caused by haemostatic failure and infusion of plasma or coagulation factor concentrates may not be effective.

Contemporary management of major haemorrhage in critical care

Haemorrhagic shock is frequent in critical care settings and responsible for a high mortality rate due to multiple organ dysfunction and coagulopathy. The management of critically ill patients with bleeding and shock is complex, and treatment of these patients must be rapid and definitive. The administration of large volumes of blood components leads to major physiological alterations which must be mitigated during and after bleeding. Early recognition of bleeding and coagulopathy, understanding the underlying pathophysiology related to specific disease states, and the development of individualised management protocols are important for optimal outcomes. This review describes the contemporary understanding of the pathophysiology of various types of coagulopathic bleeding; the diagnosis and management of critically ill bleeding patients, including major haemorrhage protocols and post-transfusion management; and finally highlights recent areas of opportunity to better understand optimal management strategies for managing bleeding in the intensive care unit (ICU).

How to assess hemostasis in patients with severe liver disease

Patients with advanced liver diseases frequently acquire profound alterations in their hemostatic system. Simultaneous changes in procoagulant and anticoagulant systems result in a reset in the hemostatic balance with a relatively neutral net effect, although there are notable hypocoagulable and hypercoagulable features in the hemostatic system in patients with liver disease. Laboratory and clinical studies have demonstrated that patients have a relatively well-preserved hemostatic system even though routine diagnostic tests of hemostasis (prothrombin time, platelet count) suggest a bleeding tendency. Routine diagnostic tests of hemostasis are unsuitable to assess the hemostatic status of patients with liver disease, as these tests are insensitive for the concurrent prohemostatic and antihemostatic changes in these patients. These tests are, however, frequently requested in patients with liver disease, as they are well established indicators of severity of liver disease. This paper will discuss commonly used diagnostic and research-type hemostatic tests and will outline how test results should be interpreted in patients with liver disease.

Increased platelet ratio in patients with decompensated cirrhosis indicates a higher risk of portal vein thrombosis

Patients with decompensated cirrhosis are at risk of portal vein thrombosis (PVT). We prospectively investigated whether alterations of platelet aggregation can predict PVT in decompensated cirrhosis. At baseline, all patients underwent whole-blood aggregometry (Multiplate®) to assess ADP-induced platelet aggregation. Aggregometry results were expressed as the ratio between platelet aggregation and platelet count (PLT ratio). Then, patients with cirrhosis were prospectively followed for 1 year for PVT development. One-hundred and twenty-eight patients with decompensated cirrhosis were included (Child-Pugh A/B/C 12/39/49%). The cumulative incidence of PVT was 14%. On multivariate analysis, the PLT ratio (OR 4.5, 95% CI 2.63-7.67; p < .0001) and Child-Pugh C versus A/B (OR 4.1, 95% CI 1.18-14.80; p = .03) were independently associated with PVT. The discriminative ability of the PLT ratio was higher than Child-Pugh (AUC 0.92 vs 0.70, p < .0001). A PLT ratio > 0.75 had 83% sensitivity and 84% specificity for PVT. In conclusion, the PLT ratio by Multiplate® seems a promising thrombotic biomarker in decompensated cirrhosis.