Fibrin clot quality in acutely ill cirrhosis patients: Relation with outcome and improvement with coagulation factor concentrates

A combination of clot formation abnormalities in thromboelastometry has a high prognostic value in patients with acute-on-chronic liver failure

BACKGROUND

Global coagulation tests offer a better tool to assess procoagulant and anticoagulant pathways, fibrinolysis and clot firmness and evaluate more accurately coagulation defects compared to conventional coagulation tests. Their prognostic role in acute-on-chronic liver disease (ACLF) or acute decompensation (AD) has not been well established.

AIMS

To assess the properties and prognostic value of the coagulation profile measured by rotational thromboelastometry (ROTEM) in ACLF and AD.

METHODS

84 consecutive patients (35 ACLF and 49 AD) were prospectively studied. Twenty healthy persons matched for age and gender were used as controls. 'Hypocoagulable' or 'hypercoagulable' profiles on admission were assessed based on nine ROTEM parameters and mortality was recorded at 30 and 90 days.

RESULTS

Individual ROTEM parameters denoted significantly more hypocoagulability in patients compared to controls. 'Hypocoagulable' profile (defined as a composite of 4 or more ROTEM parameters outside the range) was associated with more severe liver disease assessed either as MELD or Child-Pugh scores ( P  < 0.001 for both) and higher 30-day mortality (Log-rank P  = 0.012). 'Hypocoagulable' profile (HR 3.160, 95% CI 1.003-9.957, P  = 0.049) and ACLF status (HR 23.786, 95% CI 3.115-181.614, P  = 0.002) were independent predictors of 30-day mortality, in multivariate model. A higher early mortality rate was shown in ACLF patients with 'hypocoagulable' phenotype compared to those without (Log-rank P  = 0.017). 'Hypocoagulable' profile was not associated with mortality in AD.

CONCLUSION

'Hypocoagulable' profile was associated with more advanced liver disease and higher short-term mortality in patients with ACLF.

Serial rotational thromboelastometry measurements show worsening hypocoagulability in acute-on-chronic liver failure and are associated with the severity of liver disease

Background

Viscoelastic tests are used to better understand the complex picture of hemostasis in cirrhosis. Limited data exist regarding the clinical relevance of rotational thromboelastometry (ROTEM) in acute-on-chronic liver failure (ACLF) or acute decompensation (AD). We examined the pattern and role of sequential observations of 9 ROTEM components in both ACLF and AD groups.

Method

ROTEM measurements were compared within and between groups at 3 time points: on admission (T1), at 24 h (T2) and 48 h post-admission (T3).

Results

Forty-two consecutive patients (22 ACLF, 20 AD) were included. ROTEM determinants exhibited significant hypocoagulable deterioration in ACLF but not in AD over the 3 time points in clot formation time (CFT)EXTEM (P=0.01), maximum clot firmnessEXTEM (P=0.014), CFTINTEM (P<0.001), and alphaINTEM (P=0.028). The sum of hypocoagulable determinants increased from T1 to T3 in ACLF (P=0.029), but remained stable in AD. Five ROTEM variables showed significant differences towards hypocoagulability in ACLF compared to AD at T3. A "hypocoagulable" profile was associated with more severe liver disease (P<0.001 for model for end-stage liver disease [MELD] or Child-Pugh scores) and higher 30- and 90-day mortality (log-rank P=0.001 and P=0.013, respectively) but no more bleeding episodes or transfusions. Two ROTEM variables displayed strong correlations with MELD at T1 and 7 at T3 (|r coefficient|>0.5).

Conclusions

ROTEM measurements indicated worsening hypocoagulability shortly post-admission compared to baseline in ACLF, but remained stable in AD. The hypocoagulable derangement was mostly correlated with the severity of liver disease and higher short-term mortality, but not more bleeding episodes.

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.

Review article: Emerging and current management of acute-on-chronic liver failure

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a clinically and pathophysiologically distinct condition from acutely decompensated cirrhosis and is characterised by systemic inflammation, extrahepatic organ failure, and high short-term mortality.

AIMS

To provide a narrative review of the diagnostic criteria, prognosis, epidemiology, and general management principles of ACLF. Four specific interventions that are explored in detail are intravenous albumin, extracorporeal liver assist devices, granulocyte-colony stimulating factor, and liver transplantation.

METHODS

We searched PubMed and Cochrane databases for articles published up to July 2023.

RESULTS

Approximately 35% of hospital inpatients with decompensated cirrhosis have ACLF. There is significant heterogeneity in the criteria used to diagnose ACLF; different definitions identify different phenotypes with varying mortality. Criteria established by the European Association for the Study of the Liver were developed in prospective patient cohorts and are, to-date, the most well validated internationally. Systemic haemodynamic instability, renal dysfunction, coagulopathy, neurological dysfunction, and respiratory failure are key considerations when managing ACLF in the intensive care unit. Apart from liver transplantation, there are no accepted evidence-based treatments for ACLF, but several different approaches are under investigation.

CONCLUSION

The recognition of ACLF as a distinct entity from acutely decompensated cirrhosis has allowed for better patient stratification in clinical settings, facilitating earlier engagement with the intensive care unit and liver transplantation teams. Research priorities over the next decade should focus on exploring novel treatment strategies with a particular focus on which, when, and how patients with ACLF should be treated.

Fibrin clots from patients with acute-on-chronic liver failure are weaker than those from healthy individuals and patients with sepsis without underlying liver disease

BACKGROUND

Previous studies identified decreased clot permeability, without differences in fibrin fiber density in clots, from patients with cirrhosis compared with those from healthy controls (HCs). Fibrinogen hypersialylation could be the reason for this discrepancy.

OBJECTIVES

The aim of this work was to study mechanical properties of clots and reassess clot permeability in relation to hypersialylation in patients with stable cirrhosis, acute decompensation, and acute-on-chronic liver failure (ACLF). Sepsis patients without liver disease were included to distinguish between liver-specific and inflammation-driven phenotypes.

METHODS

Pooled plasma was used for rheology and permeability experiments. Permeability was assessed with compression using a rheometer and by liquid permeation. Purified fibrinogen treated with neuraminidase was used to study the effects of fibrinogen hypersialylation on liquid permeation.

RESULTS

Mechanical properties of clots from patients with stable cirrhosis and acute decompensation were similar to those of clots from HCs, but clots from patients with ACLF were softer and ruptured at lower shear stress. Clots from sepsis patients without liver disease were stiffer than those from the other groups, but this effect disappeared after adjusting for increased plasma fibrinogen concentrations. Permeability was similar between clots under compression from HCs and clots under compression from patients but decreased with increasing disease severity in liquid permeation. Removal of fibrinogen sialic acid residues increased permeability more in patients than in controls.

CONCLUSION

Clots from patients with ACLF have weak mechanical properties despite unaltered fibrin fiber density. Previous liquid permeation experiments may have erroneously concluded that clots from patients with ACLF are prothrombotic as fibrinogen hypersialylation leads to underestimation of clot permeability in this setting, presumably due to enhanced water retention.

Bleeding and Thrombotic Complications in Patients With Cirrhosis: A State-of-the-Art Appraisal

Much has evolved over the past 25 years regarding our understanding of the coagulopathy of liver disease. Paradoxically, this form of coagulopathy is relatively hypercoagulability despite the common clinical impression of a hemorrhagic tendency. The latter is largely driven by portal-mesenteric venous pressure (ie, portal hypertension) and has little to do with hemostatic pathways. It cannot be emphasized enough that the INR does not offer a meaningful measure in this situation and may lead to interventions such as fresh frozen plasma that can actually worsen portal pressure and hence pressure-driven bleeding. With regard to procedure-related bleeding, we point out substantial differences in the definition of high-risk procedures and propose a new operational definition dependent on the applicability of local hemostatic measures, although this requires further investigation. The common occurrence of venous thrombosis in these patients requires careful consideration of hemostatic pathways and overall risk and benefit of intervention. The decision regarding anticoagulation therapy needs to be driven not only by a global assessment including history of non-portal hypertensive-related bleeding, but also by fall risk which can result in head trauma in patients prone to encephalopathy. This is probably best estimated by frailty but has yet to be adequately investigated. In the background of these concerns, several superimposed and complex conditions including infections and renal dysfunction should be taken into account. Inherited forms of thrombophilia in the setting of cirrhosis perhaps do not outweigh the thrombophilia inherent to liver disease but warrant further consideration.

Haemostasis in cirrhosis: Understanding destabilising factors during acute decompensation

Hospitalised patients with decompensated cirrhosis are in a rebalanced haemostatic state due to a parallel decline in both pro- and anti-haemostatic pathways. However, this rebalanced haemostatic state is highly susceptible to perturbations and may easily tilt towards hypocoagulability and bleeding. Acute kidney injury, bacterial infections and sepsis, and progression from acute decompensation to acute-on-chronic liver failure are associated with additional alterations of specific haemostatic pathways and a higher risk of bleeding. Unfortunately, there is no single laboratory method that can accurately stratify an individual patient's bleeding risk and guide pre-procedural prophylaxis. A better understanding of haemostatic alterations during acute illness would lead to more rational and individualised management of hospitalised patients with decompensated cirrhosis. This review will outline the latest findings on haemostatic alterations driven by acute kidney injury, bacterial infections/sepsis, and acute-on-chronic liver failure in these difficult-to-treat patients and provide evidence supporting more tailored management of bleeding risk.

Fibrin clot properties and thrombus composition in cirrhosis

Patients with cirrhosis frequently acquire profound hemostatic alterations, which may affect thrombus quality and composition-factors that determine the susceptibility to embolization and fibrinolysis. In this narrative review, we describe in vitro studies on fibrin clot formation and quantitative and qualitative changes in fibrinogen in patients with cirrhosis, and describe recent findings on the composition of portal vein thrombi in patients with cirrhosis. Patients with mild cirrhosis have increased thrombin generation capacity and plasma fibrinogen levels, which may be balanced by delayed fibrin polymerization and decreased factor XIII levels. With progressing illness, plasma fibrinogen levels decrease, but thrombin generation capacity remains elevated. Fibrinogen is susceptible to posttranslational protein modifications and is, for example, hypersialylated and carbonylated in patients with cirrhosis. Despite changes in thrombin generation, factor XIII levels and the fibrinogen molecule, fibrin fiber thickness, and density are normal in patients with cirrhosis. Paradoxically, fibrin clot permeability in patients with cirrhosis is decreased, possibly because of posttranslational protein modifications. Most patients have normal fibrinolytic potential. We have recently demonstrated that portal vein thrombosis is likely a misnomer as the material that may obstruct the cirrhotic portal vein frequently consists of a thickened portal vein wall, rather than a true thrombus. Patients with cirrhosis often have thrombocytopenia and anemia, which may also affect clot stability and composition, but the role of cellular components in clot quality in cirrhosis has not been extensively studied. Finally, we summarize abstracts on fibrin formation and clot quality that were presented at the ISTH 2022 meeting in London.