Rotational thromboelastometry can detect factor XIII deficiency and bleeding diathesis in patients with cirrhosis

Hyperfibrinolysis Detection During Liver Transplantation Using Viscoelastometry

BACKGROUND

End-stage liver disease induces a precarious hemostatic equilibrium, named rebalanced hemostasis. Liver transplantation additionally causes profound disturbances in the hemostatic balance. Hyperfibrinolysis poses a relevant impairment to the coagulation process during liver transplantation. During surgery, the hemostatic management is guided by viscoelastic monitoring systems. The aim of this prospective, observational study was to evaluate the incidence of hyperfibrinolysis during liver transplantation using different viscoelastic assays, namely an ecarin-based test and a tissue factor-based test.

METHODS

Blood sampling was done at five measurement time points during liver transplantation (T1 induction of general anesthesia, T2 start of anhepatic phase, T3 end of anhepatic phase, T4 10 min after reperfusion, T5 end of surgery). Viscoelastic testing included ClotPro assays EX-test, FIB-test, AP-test, and ECA-test. Hyperfibrinolysis was defined as a maximum lysis of at least 15%. Lysis detection time (LDT) served as an indicator for the velocity of lysis, marking the time point when less than 85% of the clot are extant.

RESULTS

Thirty transplantation surgeries were included. A total of 150 viscoelastic measurements have been performed. The ECA-test detected hyperfibrinolysis significantly more often (31 [21%] vs. 22 [15%] out of 150, p = 0.039) and in a higher number of patients than the EX-test. The ECA-test revealed hyperfibrinolysis significantly earlier compared to the EX-test (median LDT 2100 s [1500/2900] vs. 3300 s [2400/3800], p < 0.001).

CONCLUSION

This study demonstrates higher sensitivity of the ecarin-test than the tissue-factor-test in monitoring hyperfibrinolysis, with more frequent and earlier detection of this coagulopathy.

TRIAL REGISTRATION

German Clinical Trials Register: DRKS00032827.

Perioperative Application of Point-of-care Test for Blood Viscoelasticity: A Good Choice for Coagulation Management

Point-of-care test (POCT) of blood viscoelasticity can reflect the coagulation status of patients accurately and timely. POCT can be used to monitor the effect of preoperative antithrombotic drugs on coagulation function, which will inform the selection of appropriate surgical timing. It can also be applied to analyze the reasons of intraoperative bleeding and guide the transfusion of blood products. Also, it is useful to assess the risk of postoperative thromboembolism and hint the need for prophylactic anticoagulation. This article mainly introduces the principles and clinical application of several frequently used POCTs for blood viscoelasticity, with a focus on their role in special types of diseases in which coagulation function changes significantly, such as cardiac disease, trauma, pathological obstetrics, and liver disease. Furthermore, we describe the role of microparticle in coagulation, which is a novel potential biomarker for diagnosing thrombotic disorders and possesses potential to be applied in POCTs of blood viscoelasticity.

Rotational thromboelastometry predicts future bleeding events in patients with cirrhosis

BACKGROUND AND AIMS

Patients with cirrhosis of the liver are in a delicate state of rebalanced haemostasis and are at risk of developing both bleeding and thrombotic complications. Conventional haemostatic tests are unable to predict bleeding and thrombosis in these patients. We aimed to explore the role of Rotational Thromboelastometry (ROTEM) in predicting bleeding and thrombotic events in patients with cirrhosis.

METHODS

We conducted a prospective cohort study of patients with cirrhosis at two metropolitan hospitals. All patients underwent ROTEM analysis and were then followed to record any bleeding and thrombotic events. Univariate and multivariate logistic regression analyses were performed to explore associations with bleeding and thrombotic events.

RESULTS

Nineteen of the 162 patients recruited experienced a bleeding event within one year of ROTEM analysis. On univariate analysis, maximum clot firmness (MCF) using both EXTEM and INTEM tests was significantly reduced in patients who had a bleeding event, compared to those who did not (50 mm vs. 57 mm, p < 0.01 and 48 mm vs. 54 mm, p < 0.01, respectively). In addition, on univariate analysis, clotting time (CT) in the INTEM test was prolonged in the bleeding group (214 s vs. 198 s, p = 0.01). On multivariate analysis, only MCFEX was a significant predictor of bleeding events. In contrast, there was no association found between ROTEM parameters and development of thrombosis within a one-year period.

CONCLUSIONS

ROTEM may provide a useful tool in predicting future bleeding events in patients with cirrhosis. Larger studies are required to further validate this finding and explore its application in clinical practice.

Early Goal-Directed Hemostatic Therapy for Severe Acute Bleeding Management in the Intensive Care Unit: A Narrative Review

This is a narrative review of the published evidence for bleeding management in critically ill patients in different clinical settings in the intensive care unit (ICU). We aimed to describe "The Ten Steps" approach to early goal-directed hemostatic therapy (EGDHT) using point-of-care testing (POCT), coagulation factor concentrates, and hemostatic drugs, according to the individual needs of each patient. We searched National Library of Medicine, MEDLINE for publications relevant to management of critical ill bleeding patients in different settings in the ICU. Bibliographies of included articles were also searched to identify additional relevant studies. English-language systematic reviews, meta-analyses, randomized trials, observational studies, and case reports were reviewed. Data related to study methodology, patient population, bleeding management strategy, and clinical outcomes were qualitatively evaluated. According to systematic reviews and meta-analyses, EGDHT guided by viscoelastic testing (VET) has been associated with a reduction in transfusion utilization, improved morbidity and outcome in patients with active bleeding. Furthermore, literature data showed an increased risk of severe adverse events and poor clinical outcomes with inappropriate prophylactic uses of blood components to correct altered conventional coagulation tests (CCTs). Finally, prospective, randomized, controlled trials point to the role of goal-directed fibrinogen substitution to reduce bleeding and the amount of red blood cell (RBC) transfusion with the potential to decrease mortality. In conclusion, severe acute bleeding management in the ICU is still a major challenge for intensive care physicians. The organized and sequential approach to the bleeding patient, guided by POCT allows for rapid and effective bleeding control, through the rational use of blood components and hemostatic drugs, since VET can identify specific coagulation disorders in real time, guiding hemostatic therapy with coagulation factor concentrates and hemostatic drugs with individual goals.

Evaluation of coagulopathy in cirrhotic patients: A scoping review of the utility of viscoelastic testing

BACKGROUND

Cirrhosis causes significant coagulopathy. Traditional coagulation tests may not accurately measure coagulopathy in well-compensated patients with cirrhosis. Viscoelastic tests are functional tests that may better assess coagulopathy in cirrhotic patients.

METHODS

We searched PubMed, ScienceDirect, Google Scholar, and grey literature using terms meaning viscoelastic testing and cirrhosis. After reviewing over 500 titles and abstracts, 40 full-text papers met inclusion criteria.

RESULTS

Twenty-two papers found viscoelastic testing was a better indicator of baseline coagulation than traditional testing in cirrhosis. Nineteen additional papers evaluated the utility of peri-procedural viscoelastic testing and found they led to a reduction in blood product administration without increasing risk of hemorrhage, thrombotic events, or other complications.

CONCLUSIONS

The usage of viscoelastic testing in patients with cirrhosis allows for better assessment of coagulopathy, resulting in improved outcomes. Educating physicians to optimize care of this high-risk group is necessary to further improve their treatment.

Association of Heparin-Like Effect, Factor VII/XIII Deficiency and Fibrinolysis with Rebleeding Risk in Cirrhosis with Acute Variceal Bleeding

BACKGROUND

Hyperfibrinolysis and coagulation dysfunction may occur in cirrhotic patients with acute variceal bleed (AVB) despite successful endotherapy.

AIMS

To prospectively study the association of endogenous heparinoids and coagulation dysfunction with variceal rebleeding and outcome in cirrhosis.

METHODS

Consecutive patients were assessed with conventional coagulation tests, SONOCLOT™ [(global(gb) and heparinase(h) treated] and factors VII, VIII, XIII, X, tissue plasminogen activator, and plasminogen activator inhibitor ELISA assays in a university hospital. Heparin-like-effect (HLE) was defined as ≥ 20% difference in paired gb/h-SONOCLOT™ traces for activated clotting time (ACT).

RESULTS

Of 143 patients screened, 90 (46.4 ± 11.7 years, males 82.2%, ethanol-related 58.8%) were recruited, who bled from esophageal varices (81,90.0%), gastric varices (6,6.6%), or esophageal varices with portal hypertensive gastropathy (3,3.3%). Twenty (21.7%) had early rebleeding, mainly post-variceal ligation ulcer related (70%). Patients who rebled had low Factor XIII [1.6 (1.2-2.1) vs 2.4 ng/ml (2.0-2.8) P = 0.035] and Factor VII (94.1 ± 46.9 vs. 124.0 ± 50.4, P = 0.023). On receiver operating curve analysis, the gbACT > 252 s (sensitivity 86.8%, specificity 76.9%, P < 0.001), hACT > 215 s (sensitivity 71.1%, specificity 70.3%, P < 0.001), and HLE > 50% (sensitivity 69.5%, specificity 70.3%, P = 0.006) predicted rebleeding. Baseline Factor VIII (HR 1.26; 95% CI 1.17-1.34, P < 0.001), low factor VII (HR 0.89; 95% CI 0.76-0.98, P = 0.035), and lysis (HR 1.25, 95% CI 1.17-1.33, P < 0.001) predicted mortality. Endogenous heparinoids at baseline predicted sepsis (HR 1.8; 95% CI 1.4-6.5; P = 0.022), rebleeding events (HR 1.2; 95% CI 1.1-6.3; P = 0.030), and mortality (HR 1.1; 95% CI 1.0-4.6; P = 0.030).

CONCLUSIONS

Hyperfibrinolysis, Factor VII/XIII deficiency, and HLE are associated with rebleeding after AVB. Trial Registration NCT04111120 available from https://clinicaltrials.gov/ct2/show/NCT04111120 .

Haemostatic support in postpartum haemorrhage: A review of the literature and expert opinion

Postpartum haemorrhage (PPH) remains the leading cause of pregnancy-related deaths worldwide. Typically, bleeding is controlled by timely obstetric measures in parallel with resuscitation and treatment of coagulopathy. Early recognition of abnormal coagulation is crucial and haemostatic support should be considered simultaneously with other strategies as coagulopathies contribute to the progression to massive haemorrhage. However, there is lack of agreement on important topics in the current guidelines for management of PPH. A clinical definition of PPH is paramount to understand the situation to which the treatment recommendations relate; however, reaching a consensus has previously proven difficult. Traditional definitions are based on volume of blood loss, which is difficult to monitor, can be misleading and leads to treatment delay. A multidisciplinary approach to define PPH considering vital signs, clinical symptoms, coagulation and haemodynamic changes is needed. Moreover, standardised algorithms or massive haemorrhage protocols should be developed to reduce the risk of morbidity and mortality and improve overall clinical outcomes in PPH. If available, point-of-care testing should be used to guide goal-directed haemostatic treatment. Tranexamic acid should be administered as soon as abnormal bleeding is recognised. Fibrinogen concentrate rather than fresh frozen plasma should be administered to restore haemostasis where there is elevated risk of fibrinogen deficiency (e.g., in catastrophic bleeding or in cases of abruption or amniotic fluid embolism) as it is a more concentrated source of fibrinogen. Lastly, organisational considerations are equally as important as clinical interventions in the management of PPH and have the potential to improve patient outcomes.

Rational hemostatic management in cirrhosis: from old paradigms to new clinical challenges

INTRODUCTION

Patients with cirrhosis are at risk of both thrombotic and hemorrhagic events. Traditional hemostatic tests are inadequate to assess the complex and fragile balance of hemostasis in this setting, especially in advanced stages of disease such as decompensated cirrhosis or acute on chronic liver failure (ACLF). Furthermore, the indiscriminate use of pro-hemostatic agents for prophylaxis and treatment of bleeding episodes is still debated and often contraindicated. Alongside, splanchnic, and peripheral thrombotic events are frequent in this population and require management that involves a careful balance between risks and benefits of antithrombotic therapy.

AREAS COVERED

This review aims to address the state of the art on the clinical management of the hemostatic balance of cirrhosis in terms of established knowledge and future challenges.

EXPERT OPINION

The old paradigm of cirrhosis as a naturally anticoagulated condition has been challenged by more sophisticated global tests of hemostasis. Integrating this information in the clinical decision-making is still challenging for physicians and experts in hemostasis.

The coagulopathy underlying rotational thromboelastometry derangements in trauma patients: a prospective observational multicenter study

BACKGROUND

Viscoelastic hemostatic assays such as rotational thromboelastometry (ROTEM®) are used to guide treatment of trauma induced coagulopathy. We hypothesized that ROTEM derangements reflect specific coagulation factor deficiencies after trauma.

METHODS

Secondary analysis of a prospective cohort study in six European trauma centers in patients presenting with full trauma team activation. Patients with dilutional coagulopathy and patients on anticoagulants were excluded. Blood was drawn on arrival for measurement of ROTEM®, coagulation factor levels and markers of fibrinolysis. ROTEM® cut-off values to define hypocoagulability were: EXTEM clotting time (CT) >80s, EXTEM clot amplitude after 5 minutes (CA5) <40mm, EXTEM lysis at 30 minutes (Li30) <85%, FIBTEM clot amplitude after 5 minutes (CA5) <10mm and FIBTEM lysis at 30 minutes (Li30) <85%. Based on these, patients were divided into 7 deranged ROTEM® profiles and compared to the reference group (ROTEM® values within reference range). The primary endpoint was coagulation factors levels and fibrinolysis.

RESULTS

Of 1828 patients, 40% had ROTEM® derangements 40.0%, most often consisting of a combined decrease in EXTEM and FIBTEM CA5, that was present in 217 (11.9%) patients. While an isolated EXTEM CT>80s had no impact on mortality, all other ROTEM® derangements were associated with increased mortality. Also, coagulation factor levels in this group were similar to patients with a normal ROTEM®. Of coagulation factors, decrease was most apparent for fibrinogen (with a nadir of 0.78 g/L) and for factor V levels (with a nadir of 22.8%). In addition, increased fibrinolysis can be present when LI30 is normal but EXTEM and FIBTEM CA5 is decreased.

CONCLUSION

Coagulation factor levels and mortality in the group with an isolated clotting time prolongation is similar to patients with a normal ROTEM ®. Other ROTEM ® derangements are associated with mortality and reflect a depletion of fibrinogen and factor V. Increased fibrinolysis can be present when lysis after 30 minutes is normal.

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

BACKGROUND & AIMS

Patients with liver disease may acquire substantial changes in their hemostatic system, which are most pronounced in patients who are critically ill. Changes in the quality of the fibrin clot in critically ill patients have not been studied in detail. Here we assessed markers of fibrin clot quality and effects of coagulation factor concentrates in patients with acutely decompensated (AD) cirrhosis and acute on chronic liver failure (ACLF).

METHODS

We measured plasma levels of fibrinogen, factor XIII, prothrombin and performed thrombin generation assays in 52 AD patients, 58 ACLF patients and 40 controls. In addition, we examined the effects of coagulation factor concentrates on functional assays of fibrin quality.

RESULTS

We found increased thrombin generating capacity in both AD and ACLF in comparison with healthy controls. Plasma levels of prothrombin, fibrinogen, and factor XIII were lower in patients compared to controls, appeared lower in ACLF compared to AD patients, and were related to clinical outcomes. Fibrinogen concentrate, but not factor XIII or prothrombin complex concentrate, improved clot quality in vitro. Prothrombin complex concentrate increased the resistance of the clot to break down.

CONCLUSIONS

We have demonstrated elevated thrombin generation but decreased plasma levels of prothrombin, fibrinogen and FXIII in acutely ill patients with cirrhosis. In addition, we showed that fibrinogen concentrate and PCCs, but not factor XIII concentrate, improve clot properties in patient plasma. Whether there is true clinical benefit from coagulation factor concentrates in prevention or treatment of bleeding requires further study.

LAY SUMMARY

Patients with liver diseases are at risk of bleeding, but mechanisms involved in this bleeding risk are incompletely understood. We studied components that determine the stability of the blood clot and found that concentrations of certain proteins involved in clot stability are present in low levels in acutely ill patients with liver disease. We furthermore demonstrated that some clinically available drugs improve the stability of blood clots from these patients in a test tube.

Management of Thrombocytopenia and Coagulopathy in Patients with Chronic Liver Disease Undergoing Therapeutic Endoscopic Interventions

Management of coagulopathy in patients with advanced liver disease undergoing therapeutic endoscopic procedures is complex. Improvements in the understanding of hemostasis at a physiologic level have highlighted the inaccuracy of currently available clinical tests, like platelet count and prothrombin time, in estimating hemostasis in patients with cirrhosis. With identification of novel factors that contribute to bleeding risk in patients with cirrhosis, there is a dearth of clinical trial data that account for all potentially relevant factors and that examine interventions to reduce bleeding risk. Precise recommendations regarding transfusion strategies based on hemostatic test results in patients with cirrhosis are impractical.

Factor XIII and surgical bleeding. A narrative review

FXIII is the final factor in the coagulation cascade. It converts soluble fibrin monomers into a stable fibrin clot, prevents premature degradation of fibrin, participates in wound healing, and helps prevent the loss of the endothelial barrier function. FXIII deficiency is believed to be rare, and this may explain why clinicians do not routinely take it into consideration. Congenital FXIII deficiency is a rare disease with a reported prevalence of 1 per million. However, the prevalence of acquired FXIII deficiency is much higher. Acquired forms have been described in patients with decreased hepatic or bone marrow synthesis, hyperconsumption and increased degradation by autoantibodies. This review offers guidance on how to suspect and diagnose FXIII deficiency in both the preoperative consultation and different surgical settings. We also analyze current scientific evidence in order to clarify when and why this clinical situation should be suspected, and how it may be treated.

Management of Coagulopathy in Bleeding Patients

Early recognition of coagulopathy is necessary for its prompt correction and successful management. Novel approaches, such as point-of-care testing (POC) and administration of coagulation factor concentrates (CFCs), aim to tailor the haemostatic therapy to each patient and thus reduce the risks of over- or under-transfusion. CFCs are an effective alternative to ratio-based transfusion therapies for the correction of different types of coagulopathies. In case of major bleeding or urgent surgery in patients treated with vitamin K antagonist anticoagulants, prothrombin complex concentrate (PCC) can effectively reverse the effects of the anticoagulant drug. Evidence for PCC effectiveness in the treatment of direct oral anticoagulants-associated bleeding is also increasing and PCC is recommended in guidelines as an alternative to specific reversal agents. In trauma-induced coagulopathy, fibrinogen concentrate is the preferred first-line treatment for hypofibrinogenaemia. Goal-directed coagulation management algorithms based on POC results provide guidance on how to adjust the treatment to the needs of the patient. When POC is not available, concentrate-based management can be guided by other parameters, such as blood gas analysis, thus providing an important alternative. Overall, tailored haemostatic therapies offer a more targeted approach to increase the concentration of coagulation factors in bleeding patients than traditional transfusion protocols.

Spontaneous Bilateral Subdural Hematomas in a Patient With Cryptogenic Liver Cirrhosis

Spontaneous subdural hematoma (SDH) in cirrhotic patients is a rarely described condition in the literature and carries a high mortality rate. Several factors can potentially contribute to SDH development in cirrhosis, including coagulation cascade defects, thrombocytopenia, arteriovenous malformations, and cerebral atrophy. Clinicians should always keep spontaneous development of SDH in the differential diagnosis of acute encephalopathy in patients with end-stage liver disease, and prompt head imaging should be considered. We report a unique case of a 64-year-old patient with cryptogenic liver cirrhosis who was found to have spontaneous, bilateral SDHs while undergoing workup for acute encephalopathy.

Liver failure-future challenges and remaining questions

This review compiles the current state of controversial aspects of liver failure and outlines future challenges. The definition of acute liver failure (ALF) is widely accepted and implies no previous liver injury whereas the term "acute-on-chronic liver failure" remains contested. We will promote a concept, in which we differentiate three types of liver failure: ALF, acute-on-chronic liver failure (AOCLF) and acute-on-liver-cirrhosis (AOCi). The mechanistical insights into the coagulation system in patients with hepatic insufficiency have increased fundamentally in the past 10 years. Therefore, we follow now the concept of the so-called rebalanced hemostasis. This lower-level equilibrium arises from the fact that most coagulation factors and inhibitors are synthesized within the liver. We will demonstrate the advantage of viscoelastic test methods, which can assess the coagulation situation in patients with liver insufficiency much more precisely than conventional global coagulation tests. The therapeutic option of emergency liver transplantation (ELT) has significantly improved the prognosis of patients with ALF. However, limiting factors such as shortage of organs increase more and more the need for reliable prognostic markers. Due to a better understanding of the regenerative process during ALF new survival markers and prognostic tools have been emerging on the horizon in the last decade. Therefore, we will describe the current state of research in this field.

Risk factors associated with bleeding after prophylactic endoscopic variceal ligation in cirrhosis

BACKGROUND

Prophylactic endoscopic variceal band ligation (EVL) is frequently performed in patients with liver cirrhosis. The aim of our study was to identify factors associated with early upper gastrointestinal bleeding (UGIB) in cirrhosis patients after prophylactic EVL.

METHODS

787 nonemergency EVLs performed in 444 patients in two German University medical centers were analyzed retrospectively.

RESULTS

Within 30 days after EVL, 38 UGIBs were observed (4.8 % of all procedures). Bilirubin levels (hazard ratio [HR] 1.5, 95 % confidence interval [CI] 1.2-2.0 for a 2-fold increase) and presence of varices grade III/IV according to Paquet (HR 2.6, 95 %CI 1.3-5.0 compared with absence or smaller sized varices) were independently associated with UGIB following EVL. International normalized ratio (INR) was associated with bleeding events in the univariate analysis but did not reach statistical significance after adjustment for bilirubin and presence of varices grade III/IV (HR 1.2, 95 %CI 0.9-1.6 for an increase by 0.25). There was no statistically significant association between platelet count or fibrinogen levels and UGIB. Substitution of coagulation products did not affect incidence of bleeding after EVL, which also applied to patients with "coagulopathy" (INR > 1.5 and/or platelet count < 50 × 10⁹/L). No association between proton pump inhibitor therapy and post-EVL UGIB was observed.

CONCLUSIONS

EVL is a safe procedure and immediate bleeding complications are rare. Serum bilirubin levels and size of varices, rather than coagulation indices, are associated with UGIB after EVL. Our data do not support the preventive substitution of blood or coagulation products.

Hyper- and hypocoagulability in COVID-19 as assessed by thromboelastometry -two case reports

BACKGROUND

Coronavirus disease (COVID-19)-associated coagulopathy is most often characterized by elevated D-dimer, interleukin-6, and plasma fibrinogen concentrations as well as hypercoagulability in thromboelastometry with increased clot firmness in the EXTEM, INTEM, and FIBTEM assays. Clinically, it manifests with a very high incidence of thrombosis, particularly in the pulmonary system, whereas bleeding complications are infrequent.

CASE

Here, we describe two critically ill patients with COVID-19 admitted to our intensive care unit demonstrating different thromboelastometry and biomarker patterns. One patient presented with hypercoagulability and the other patient with hypocoagulability and fibrinolysis shutdown in thromboelastometry. The pathophysiology and the potential impact on treatment options are discussed.

CONCLUSIONS

A combination of biomarkers and thromboelastometry results can be helpful in the future to decide which therapeutic strategy might be most appropriate for critically ill patients with COVID-19. This would be an important step to establish precision medicine in this high-risk patient population.

Thromboelastography-guided Blood Product Transfusion in Cirrhosis Patients With Variceal Bleeding: A Randomized Controlled Trial

GOALS

The aim of this study was to assess the use of thromboelastography (TEG)-directed blood product transfusion in cirrhotic patients with acute variceal bleeding compared with conventional transfusion for correction of coagulopathy.

BACKGROUND

Coagulopathy is common in patients with cirrhosis. Recommendations for correction of conventional parameters of coagulation-platelets and the international normalized ratio before endoscopy in patients with acute variceal bleeding-need more validation.

STUDY

In this randomized controlled trial, cirrhotic patients with severe coagulopathy and acute variceal bleeding were randomized to either TEG-guided blood product transfusion or conventional transfusion from March 2017 to December 2017. The primary outcome was the difference in the amount of fresh frozen plasma and platelet units transfused between the groups. Secondary outcomes were rebleeding at 5 days and 42 days, and 6-week mortality.

RESULTS

Of the 60 recruited patients, 30 each were randomized to the TEG and conventional transfusion groups. There were no differences in baseline characteristic and endoscopic findings between the 2 groups. Four subjects in the TEG group received blood product transfusions versus all in the conventional transfusion group (13.3% vs. 100%; P<0.001). The control of bleeding on initial endoscopy was similar in the 2 groups. Rebleeding in the TEG and conventional transfusion groups at 5 days was similar [1 (3.3%) vs. 4 (13.3%), P=0.167], whereas it was significantly less in the TEG group at 42 days [3 (10%) vs. 11 (36.7%), P=0.012]. Mortality at 6 weeks was seen in 4 (13.3%) in the TEG group and in 8 (26.7%) patients in the conventional transfusion group (P=0.176).

CONCLUSIONS

TEG-guided strategy was associated with reduced blood product transfusion to correct coagulopathy without compromising hemostasis in cirrhotic patients (Clinical trial ID: CTRI/2017/02/007864).

Comparison of Thromboelastography and Conventional Coagulation Tests in Patients With Severe Liver Disease

OBJECTIVE

Thromboelastography (TEG) may provide rapid and clinically important coagulation information in acutely ill patients with chronic liver disease (CLD). Our objective was to describe the relationship between TEG and conventional coagulation tests (CCTs), which has not been previously explored in this population.

METHODS

In acutely ill patients with severe CLD (Child-Pugh score > 9, category C), we conducted a prospective observational study investigating coagulation assessment as measured by both CCTs and TEG. We used quantile regression to explore 30 associations between TEG parameters and corresponding CCTs. We compared TEG and CCT measures of coagulation initiation, clot formation, clot strength, and fibrinolysis.

RESULTS

We studied 34 patients on a total of 109 occasions. We observed inconsistent associations between TEG and CCT measures of coagulation initiation: TEG (citrated kaolin [CK] assay) standard reaction time and international normalized ratio: R 2 = 0.117 (P = .044). Conversely, there were strong and consistent associations between tests of clot formation: TEG (CK) kinetics time and fibrinogen: R 2 = 0.202 (P < .0001) and TEG (CK) α angle and fibrinogen 0.263 (P < .0001). We also observed strong associations between tests of clot strength, specifically TEG MA and conventional fibrinogen levels, across all TEG assays: MA (CK) and fibrinogen: R 2 = 0.485 (P < .0001). There were no associations between TEG and D-dimer levels.

CONCLUSIONS

In acutely ill patients with CLD, there are strong and consistent associations between TEG measures of clot formation and clot strength and conventional fibrinogen levels. There are weak and/or inconsistent associations between TEG and all other conventional measures of coagulation.

Acute kidney injury is associated with low factor XIII in decompensated cirrhosis

BACKGROUND/AIMS

The coagulation system is known to be rebalanced but fragile in stable cirrhosis. Acute kidney injury (AKI) is common in these patients and associated with an increased bleeding risk. We aimed to assess coagulation parameters in this population.

METHODS

We prospectively enrolled 43 hospitalized patients with decompensated cirrhosis with (n = 22) or without (n = 21) AKI. Coagulation factor levels, viscoelastic coagulation assay, and thrombin generation assay were performed and compared between these groups and a healthy reference group.

RESULTS

Conventional markers of coagulation were not statistically different between patients with and without AKI. Factor XIII was significantly reduced in all patients with cirrhosis compared to healthy controls (p = <0.0001). In patients with AKI, factor XIII was significantly lower compared to patients without AKI (AKI 38% vs. non-AKI 60% p = 0.002). In patients with cirrhosis, factor XIII had a significantly positive correlation with EXTEM maximal clot firmness (r = 0.5440, p = 0.0002) and FIBTEM maximal clot firmness (r = 0.7397, p = <0.0001) and a negative correlation with EXTEM clot formation time (-0.413, p = 0.0065).

CONCLUSIONS

Factor XIII was significantly reduced in decompensated cirrhosis patients with AKI compared to decompensated patients without AKI. These findings suggest that exacerbation of factor XIII deficiency in AKI in decompensated cirrhosis may affect bleeding risk and warrants further study.

The Effect of Immunosuppression on Coagulation After Liver Transplantation

Everolimus (EVR) is a mammalian target of rapamycin (mTOR) inhibitor commonly used for immunosuppression (IS) after liver transplantation (LT). However, there are concerns about whether mTOR inhibitors may move the hemostatic balance toward a higher likelihood of thrombosis. The present study aimed to investigate potential coagulation disorders after the administration of EVR. We evaluated 54 patients after conversion to an EVR-based IS regimen (n = 26) and compared those patients with patients who were switched to extended-release tacrolimus (TAC) but had never received EVR (n = 28). At baseline and again at 1 month and 6 months after conversion, we measured international normalized ratio, activated partial thromboplastin time, and anticoagulation and fibrinolysis factors, and we performed rotational thromboelastometry (ROTEM). Data were analyzed with a Mann-Whitney U test, a repeated-measure analysis of variance, and a Fisher's exact test. Statistical significance was set at the level of P ≤ 0.05. Plasma levels of von Willebrand factor, fibrinogen, and factor VIII were significantly higher than baseline levels at 1 month and 6 months after conversion of IS to EVR (P < 0.001); plasma levels of protein C, protein S, and plasminogen also increased significantly (P < 0.001). ROTEM confirmed a significant increase in maximum clot firmness in EXTEM, INTEM, and FIBTEM assays (P < 0.001). In all assays, maximum lysis was significantly lower than baseline levels at 1 month and 6 months after conversion to EVR. Patients converted to IS with extended-release TAC exhibited no significant changes in coagulation variables. Retrospective analysis showed a significantly higher incidence of thromboembolic complications among patients treated with EVR-based IS than among those treated with extended-release TAC (P < 0.01). In conclusion, the administration of EVR after LT seems to modify hemostasis to a procoagulant state. Thrombophilia screening before conversion may determine which patients will benefit from conversion to EVR-based IS.

The role of evidence-based algorithms for rotational thromboelastometry-guided bleeding management

Rotational thromboelastometry (ROTEM) is a point-of-care viscoelastic method and enables to assess viscoelastic profiles of whole blood in various clinical settings. ROTEM-guided bleeding management has become an essential part of patient blood management (PBM) which is an important concept in improving patient safety. Here, ROTEM testing and hemostatic interventions should be linked by evidence-based, setting-specific algorithms adapted to the specific patient population of the hospitals and the local availability of hemostatic interventions. Accordingly, ROTEM-guided algorithms implement the concept of personalized or precision medicine in perioperative bleeding management (‘theranostic’ approach). ROTEM-guided PBM has been shown to be effective in reducing bleeding, transfusion requirements, complication rates, and health care costs. Accordingly, several randomized-controlled trials, meta-analyses, and health technology assessments provided evidence that using ROTEM-guided algorithms in bleeding patients resulted in improved patient’s safety and outcomes including perioperative morbidity and mortality. However, the implementation of ROTEM in the PBM concept requires adequate technical and interpretation training, education and logistics, as well as interdisciplinary communication and collaboration.

Evaluation of hemostasis in patients with end-stage renal disease

An increased bleeding risk is reported for patients with end-stage renal disease. This study aims to analyze, whether bleeding risk can be assessed by global tests of hemostasis. Standard laboratory tests and an extended evaluation of hemostasis by rotational thromboelastometry, platelet function analyzer (PFA) and multiple electrode aggregometry as well as thrombin generation assays and measurement of fibrinolytic potential were performed in 20 patients on hemodialysis, 10 patients on peritoneal dialysis, 10 patients with chronic kidney disease stage G5 (CKD5) and in 10 healthy controls (HC). Hemoglobin was significantly lower in patients with end-stage renal disease versus HC (each p<0.01). Patients on peritoneal dialysis showed increased fibrinogen levels compared to HC (p<0.01), which were also reflected by FIBTEM results (each p<0.05). 41% of hemodialysis patients and 44% of CKD5 patients presented with prolonged PFA-ADP-test (p<0.05), while no patient on peritoneal dialysis and no HC offered this modification. Thrombin generating potential was significantly lower in patients on hemodialysis, while clot lysis time revealed a hypofibrinolytic state in patients on hemo- and peritoneal dialysis compared to HC (p<0.001). In conclusion, patients with end-stage renal disease have complex hemostatic changes with both hyper- and hypocoagulable features, which are dependent on use and type of dialysis. Hypercoagulable features include elevated fibrinogen levels and a hypofibrinolytic state, whereas hypocoagulable features include decreased thrombin generating capacity and platelet dysfunction. Our results may contribute to a more rational approach to hemostatic management in these patients.

Suboptimal use of pharmacological venous thromboembolism prophylaxis in cirrhotic patients

BACKGROUND

Cirrhosis was previously perceived as a haemorrhagic disease state due to frequent associations with coagulopathy and bleeding. However, the coagulopathy of cirrhosis is complex with defects in both procoagulant and anticoagulant factors. Derangements in common laboratory indices of coagulation do not accurately reflect bleeding risk or protection from thrombotic events.

AIMS

To assess the rate of pharmacological prophylaxis for venous thromboembolism (VTE) among hospital inpatients with cirrhosis and analyse factors associated with prophylaxis being inappropriately withheld.

METHODS

A retrospective cohort study was performed in a tertiary teaching hospital. Patients included were admitted for greater than 48 h with discharge diagnosis codes corresponding to chronic liver disease and/or cirrhosis. The use of VTE chemoprophylaxis with enoxaparin was assessed in cirrhotic patients and non-cirrhotic controls. Patient data collected included contraindications to prophylaxis, known high-risk varices, international normalised ratio (INR), creatinine, bilirubin, haemoglobin and platelet count.

RESULTS

Of 108 patients with cirrhosis eligible for VTE prophylaxis, 61 (56.5%) received prophylaxis compared to 104 (96.3%) non-cirrhotic patients. Platelets and INR were significantly different between those who did and did not receive VTE prophylaxis. On multivariate analysis, platelet count and INR were independent predictors for VTE not being administered.

CONCLUSION

The administration of chemoprophylaxis in accordance with the hospital guidelines was suboptimal in patients with cirrhosis. Platelet count and INR were independent predictors of prophylaxis use. Our results suggest persistent misperceptions that prolonged INR and thrombocytopenia predict bleeding risk in cirrhosis.

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.

Viscoelastic Monitoring to Guide Hemostatic Resuscitation in Liver Transplantation Surgery

Coagulopathic bleeding must be anticipated during liver transplantation (LT) surgery. Patients with end-stage liver disease (ESLD) often present with disease-related hematologic disturbances, including the loss of hepatic procoagulant and anticoagulant clotting factors and thrombocytopenia. Transplantation surgery itself presents additional hemostatic changes, including hyperfibrinolysis. Viscoelastic monitoring (VEM) is often used to provide targeted, personalized hemostatic therapies for complex bleeding states including cardiac surgery and major trauma. The use in these coagulopathic conditions led to its application to LT, although the mechanisms of coagulopathy in these patients are quite different. While VEM is often used during transplant surgeries in Europe and North America, evidence supporting its use is limited to a few small clinical studies. The theoretical and clinical applications of the standard and specialized VEM assays are discussed in the setting of LT and ESLD.

Thromboelastography does not predict outcome in different etiologies of cirrhosis

BACKGROUND

New laboratory tests that measure global hemostasis indicate generally preserved hemostatic function in patients with cirrhosis. It is not known whether normal hemostatic function is maintained across various subsets of patients.

OBJECTIVES

In the present study, we investigated clot generation and clot lysis kinetics in a large group of patients with different etiologies of disease.

PATIENTS/METHODS

Blood samples of 270 patients with cirrhosis were studied using thromboelastography (TEG), which measures the dynamic and physical properties of clot formation and lysis in whole blood. TEG parameters of different subsets of the patient population were compared. Correlations with routine laboratory tests as well as clinical outcomes were explored.

RESULTS

Overall, TEG parameters were normal and similar between underlying disease etiologies. A proportion of subjects showed hypocoagulable features, with the exception of patients with cholestatic cirrhosis in whom TEG readings showed hypercoagulable features. In all groups, K-time, α-Angle, and MA correlated well with platelet counts and fibrinogen plasma levels. After a mean follow-up of 2 years and 11 months, 31 patients had experienced a bleeding event, 8 had developed thrombosis, and 173 patients (64%) had undergone liver transplantation and/or had died. TEG baseline parameters were similar between patients subdivided according to outcome.

CONCLUSIONS

TEG parameters reflected generally preserved function of the hemostatic system in patients with cirrhosis, with hypo- and hypercoagulable features in subsets of patients with specific underlying disease etiologies. Abnormalities in TEG parameters did however not predict bleeding, thrombosis, or risk of liver transplantation and/or death.

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.