Thromboelastographic Evaluation of Coagulation in Patients With Liver Disease

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.

Prediction of Mid-term Platelet Transfusion in Stable Trauma Patients Using Rotational Thromboelastometry

Background

Rotational thromboelastometry (ROTEM; TEM International GmbH, Munich, Germany) is a global coagulation test that guides evidence-based platelet transfusion in trauma patients. We evaluated ROTEM parameters for predicting mid-term (five days) platelet transfusion in trauma patients.

Methods

Maximum clot firmness and clot amplitudes after 5, 10, and 15 mins (A5, A10, and A15, respectively) of fibrin-specific ROTEM (FIBTEM) and extrinsically activated ROTEM (EXTEM) were retrospectively collected from 82 hospitalized, stable, non-bleeding trauma patients after successful initial resuscitation. Platelet-specific ROTEM (PLTEM) was calculated by subtracting FIBTEM from EXTEM. Platelet transfusions were reviewed for five days after ROTEM.

Results

The areas under the curve for FIBTEM, EXTEM, and PLTEM predicting platelet concentrate transfusion of >12 U at mid-term were 0.915-0.923, 0.878-0.896, and 0.551-0.735, respectively. FIBTEM and EXTEM parameters were comparable to those of fibrinogen, fibrin/fibrinogen degradation products, D-dimer, and antithrombin III. Strong correlations (r>0.7) were noted between platelet count and EXTEM (A5, A10, and A15) or PLTEM (A5), platelet function (per platelet count) and EXTEM (A10 and A15), and fibrinogen levels and all FIBTEM parameters.

Conclusions

FIBTEM and EXTEM can reliably predict mid-term platelet transfusion in trauma patients. FIBTEM, EXTEM, and PLTEM parameters correlate with conventional coagulation tests (platelets and fibrinogen).

Risk of Bleeding in Liver Cirrhosis Receiving Direct Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND

 Direct oral anticoagulants (DOACs) are effective for the management of thromboembolic disorders. However, bleeding remains a major concern in cirrhotic patients receiving DOACs.

METHODS

 PubMed, EMBASE, and Cochrane Library databases were searched. The incidence of bleeding episodes in cirrhotic patients receiving DOACs was pooled. Odds ratios (ORs) were calculated to compare the incidence of bleeding episodes in cirrhotic patients who received DOACs versus those who received conventional anticoagulants and did not receive anticoagulants.

RESULTS

 Twenty-nine studies were included. All bleeding, major bleeding, fatal bleeding, gastrointestinal bleeding, and intracranial hemorrhage episodes were observed in 310/2,469, 100/1,388, 2/611, 166/1,886, and 5/1,147 cirrhotic patients receiving DOACs, respectively. Their pooled incidences were 13, 6, 0, 8, and 0%, respectively. They became higher in subgroup analyses of studies with advanced age, a longer treatment duration, and Child-Turcotte-Pugh class C. Compared with conventional anticoagulants, DOACs were associated with lower incidences of all bleeding (OR = 0.71, 95% confidence interval [CI] = 0.52-0.98) and major bleeding (OR = 0.55, 95% CI = 0.37-0.83) in cirrhotic patients, but not those of fatal bleeding (OR = 0.21, 95% CI = 0.04-1.28), gastrointestinal bleeding (OR = 0.78, 95% CI = 0.52-1.17), or intracranial hemorrhage (OR = 0.36, 95% CI = 0.12-1.12). The incidences of all bleeding (OR = 1.04, 95% CI = 0.22-4.79) and major bleeding (OR = 0.96, 95% CI = 0.26-3.61) did not significantly differ between cirrhotic patients with portal vein thrombosis (PVT) who received DOACs and those who did not receive anticoagulants.

CONCLUSION

 DOACs carry a low risk of bleeding in liver cirrhosis. Age, treatment duration, and Child-Turcotte-Pugh class may be associated with bleeding in cirrhotic patients receiving DOACs. The risk of bleeding is not increased by DOACs in cirrhotic patients with PVT.

Review of Thromboelastography (TEG): Medical and Surgical Applications

Thromboelastography (TEG) is a laboratory assay utilized to evaluate hemostatic properties of blood, identify coagulopathy, and guide blood product administration. While the clinical use of TEG started in the care of surgical patients, the assay has now been incorporated more routinely in the care of the medical patient as well. In this review, we explore the evolution of TEG from the historical perspective of its inception to the current state of the art of the assay. The TEG procedure and its measurements are illustrated along with a table that summarizes recommendations from across the medical and surgical literature. After each section, we review salient learning points to provide the busy clinician with information that can be immediately integrated at the bedside. We conclude with a series of summary questions to check for comprehension and direct the reader to additional resources to improve their knowledge of TEG.

Diagnosis of portal vein thrombosis in cirrhotic patients with and without hepatocellular carcinoma

Background

The levels of Annexin A5 (Annexin V) were measured in patients with and without HCC who had liver cirrhosis. These patients were followed for 12 months to determine the incidence of PVT and to determine the role of Annexin V in the diagnosis of PVT. Our goal was to look at the value of Annexin A5, platelet count, spleen size, portal flow velocity, portal vein width, Fibrosis 4, and APRI score in these individuals to see if they might be used as PVT markers.

Methods

Between March 2017 and August 2018, ninety-one HCV patients with cirrhosis with and without HCC, as well as a control group of twenty healthy people, were included in this longitudinal study at the NHTMRI. The blood anxA5 level was determined using a commercial Hyphen BioMed immunoassay using Stat Fax 4700’s Microstrip Reader l.

Results

Cirrhotic patients with and without HCC who developed PVT had higher Annexin A5 scales (5.75 + 0.18), compared to cirrhotic patients who did not develop PVT (3.63 + 1.08 (P 0.001). PVT was 20% in all cirrhotic patients after a year, 15% in cirrhotic patients without HCC, and 25% in cirrhotic patients with HCC. Cirrhotic patients who had PVT throughout the follow-up period had greater AnxA5 serum levels than cirrhotic patients who did not develop PVT.

Conclusions

In all cirrhotic patients, AnxA5 level, platelet count, spleen size, portal flow velocity, portal vein diameter, and Fibrosis 4 score might be employed as markers for PVT development.

Review article: thromboelastography in liver diseases

BACKGROUND

Patients with liver diseases have complicated haemostatic alternations, resulting in both bleeding and thromboembolic complications, which cannot be sufficiently evaluated by conventional coagulation tests (CCTs), such as platelet count or prothrombin time. Thromboelastography (TEG) is a whole blood viscoelastic test which globally reflects changes in the haemostatic system, and its utility in evaluating patients with liver disease is increasingly recognised.

AIMS

To review the current evidence and clinical significance of TEG in liver diseases.

METHODS

Literature regarding TEG and liver diseases was comprehensively searched.

RESULTS

TEG is associated closely with the severity and aetiology of liver disease, the course of infection and the risk of bleeding and death, but not the risk of portal venous system thrombosis. Additionally, TEG-guided transfusion protocols can significantly decrease the requirement for blood products compared to those guided by CCTs.

CONCLUSION

TEG can reflect the haemostatic status of liver diseases more comprehensively than CCTs. It has the potential to assess the severity of liver diseases, predict the risk of bleeding and death in patients with liver disease and guide blood product transfusion. Future studies should standardise the use of TEG for assessing disease severity and development of clinical events and guiding blood product transfusion in patients with liver diseases.

Non-invasive Liver Fibrosis Scores Are Associated With Recurrence of Postoperative Chronic Subdural Hematoma

Objective

Although liver diseases have already been identified as a risk factor for increased recurrence and mortality in patients with chronic subdural hematoma (CSDH), the association between subclinical liver disease, specifically liver fibrosis (LF), and CSDH remains unknown. In the present study, we aimed to investigate the association between the LF scores and CSDH recurrence.

Methods

We retrospectively analyzed consecutive patients with CSDH who underwent burr-hole irrigation in the First Affiliated Hospital of Wenzhou Medical University between January 2015 and December 2018. The clinical data were collected, and the LF scores were calculated including aspartate aminotransferase–platelet ratio index (APRI), fibrosis-4 (FIB-4), and Forns index. Multivariable logistic regression analysis was applied to identify the association between the LF scores and CSDH recurrence, and Cox regression model and Fine–Gray competing risks model were performed to calculate hazard ratios (HRs) for CSDH recurrence based on time-to-event outcomes. The C-statistic, the integrated discrimination improvement (IDI), and the net reclassification improvement (NRI) evaluated the additive value of the LF scores to predict the recurrence of CSDH.

Results

A total of 419 patients with CSDH were included, hematoma recurrence was observed in 62 patients (14.80%) within 1 year after surgery. The LF scores were significantly higher in those who recurred, whereas the standard hepatic assays were mostly normal. The patients were assigned to groups of high and low LF scores based on the validated cut-offs; compared with the subjects with low scores, those with high score levels had significantly higher recurrence rates. After adjusting for potential confounders, the LF scores were independently associated with CSDH recurrence, multivariable-adjusted HRs (95% CI) for those with higher levels of APRI, FIB-4, and Forns score were 4.32 (1.37–13.60), 2.56 (1.20–5.43), and 2.02 (1.07–3.79) for the recurrence of CSDH, respectively. Moreover, adding the APRI to the conventional model improved the C-statistic from 0.731 to 0.763, with an NRI and IDI of 7.50 and 1.35%, respectively. Two further commonly-used LF score indices (FIB-4 score and Forns index) yielded comparable results.

Conclusions

The data from this study first indicated that the high LF scores were significantly associated with the recurrence of CSDH and that careful follow-up in these patients may be needed.

A Liver Stiffness Measurement-Based Nomogram Predicts Variceal Rebleeding in Hepatitis B-Related Cirrhosis

Background

Cirrhosis esophageal variceal rebleeding is a major complication of chronic cirrhosis. The hepatic venous pressure gradient (HVPG) can predict the risk of rebleeding in patients with cirrhosis and has a good correlation with liver stiffness measurement (LSM). However, there are currently few studies based on liver stiffness to predict the risk of rebleeding in patients with liver cirrhosis. This study is aimed at exploring whether liver stiffness can predict rebleeding in patients with hepatitis B virus-related cirrhosis and developing an easy-to-use nomogram for predicting the risk of rebleeding in patients with liver cirrhosis undergoing secondary prevention.

Methods

A prospective analysis of 289 cirrhosis patients was performed. Univariate and multivariate analyses were used to identify independent prognostic factors to create a nomogram. The performance of the nomogram was evaluated by using a bootstrapped-concordance index and calibration plots.

Results

Use of a nonselective beta-blocker (NSBB) drug, LSM, hemoglobin, and platelet count were identified as factors that could predict rebleeding. We created a nomogram for rebleeding in cirrhosis by using these risk factors. The predictive ability of the nomogram was assessed by the C-index (0.772, 95% CI 0.732–0.822). The results of the calibration plots showed that the actual observation and prediction values obtained by the nomogram had good consistency.

Conclusions

LSM can predict the risk of rebleeding in patients with cirrhosis, while the nomogram is a conventional tool for doctors to facilitate a personalized prognostic evaluation.

Hemostasis testing in patients with liver dysfunction: Advantages and caveats

Due to concomitant changes in pro- and anti-coagulant mechanisms, patients with liver dysfunction have a “rebalanced hemostasis”, which can easily be tipped toward either a hypo- or a hypercoagulable phenotype. Clinicians are often faced with the question whether patients with chronic liver disease undergoing invasive procedures or surgery and those having active bleeding require correction of the hemostasis abnormalities. Conventional coagulation screening tests, such as the prothrombin time/international normalized ratio and the activated partial thromboplastin time have been demonstrated to have numerous limitations in these patients and do not predict the risk of bleeding prior to high-risk procedures. The introduction of global coagulation assays, such as viscoelastic testing (VET), has been an important step forward in the assessment of the overall hemostasis profile. A growing body of evidence now suggests that the use of VET might be of significant clinical utility to prevent unnecessary infusion of blood products and to improve outcomes in numerous settings. The present review discusses the advantages and caveats of both conventional and global coagulation assays to assess the risk of bleeding in patients with chronic liver disease as well as the current role of transfusion and hemostatic agents to prevent or manage bleeding.

Value and risk of percutaneous liver biopsy in patients with cirrhosis and clinical suspicion of autoimmune hepatitis

OBJECTIVE

The decision regarding whether to perform a liver biopsy in patients with cirrhosis and clinically suspected autoimmune hepatitis (AIH) remains a challenge. This study aimed to assess the utility and complications of percutaneous liver biopsy in cirrhosis for differentiating AIH from other liver conditions.

METHODS

A clinicopathological database of patients undergoing percutaneous liver biopsies for suspected AIH (unexplained hepatitis with elevated γ-globulin and autoantibody seropositivity) was reviewed to identify patients presenting with cirrhosis. Biopsy slides were reviewed by an experienced hepatopathologist who was blinded to clinical data.

RESULTS

In 207 patients who underwent liver biopsy for suspected AIH, 59 patients (mean age: 59.0±12.0 years, 83.1% female) had clinically diagnosis of cirrhosis. Mean Child-Turcotte-Pugh score was 6.6±1.6, and 44% of patients had a Child-Turcotte-Pugh score≥7. According to the revised International AIH Group (IAIHG) criteria, histology assessment combined with clinical information facilitated a diagnosis of AIH or overlap syndrome of AIH and primary biliary cholangitis (PBC) in 81.4% of cases. Liver biopsy identified other aetiologies, including PBC (n=2), non-alcoholic steatohepatitis (n=6) and cryptogenic cirrhosis (n=3). A reliable diagnosis of AIH could be made using histological category of the simplified criteria in 69.2% and 81.8% of cases using IAIHG scores before biopsy of <10 and 10-15, respectively. Three patients with cirrhosis (5.1%) experienced bleeding following biopsy, but none of 148 patients with non-cirrhosis had bleeding complication (p=0.022).

CONCLUSION

Liver biopsy provides important diagnostic information for the management of patients with cirrhosis and suspected AIH, but the procedure is associated with significant risk.

Mechanism, diagnosis, and treatment of portal vein thrombosis in cirrhosis

Portal vein thrombosis (PVT) is one of the common complications of cirrhosis. Its formation is influenced by many factors, such as liver function grade, blood coagulation state, portal vein pressure, and blood flow velocity. The treatment of patients with PVT is more difficult than that of patients without PVT, and the prognosis is poor. However, the presence of PVT is usually asymptomatic, thus early detection and intervention are important. Currently, there are different views on the mechanism of PVT. This review will discuss the mechanism of PVT and summarize its pathogenesis, diagnosis, and treatment, with an aim to provide evidence for clinical practice.

Pulmonary arterial hypertension patients display normal kinetics of clot formation using thrombelastography

Pulmonary arterial hypertension is characterized by endothelial dysfunction and microthrombi formation. The role of anticoagulation remains controversial, with studies demonstrating inconsistent effects on pulmonary arterial hypertension mortality. Clinical anticoagulation practices are currently heterogeneous, reflecting physician preference. This study uses thrombelastography and hematology markers to evaluate whether clot formation and fibrinolysis are abnormal in pulmonary arterial hypertension patients. Venous blood was collected from healthy volunteers (n = 20) and patients with pulmonary arterial hypertension (n = 20) on stable medical therapy for thrombelastography analysis. Individual thrombelastography parameters and a calculated coagulation index were used for comparison. In addition, hematologic markers, including fibrinogen, factor VIII activity, von Willebrand factor activity, von Willebrand factor antigen, and alpha2-antiplasmin, were measured in pulmonary arterial hypertension patients and compared to healthy volunteers. Between group differences were analyzed using t tests and linear mixed models, accounting for repeated measures when applicable. Although the degree of fibrinolysis (LY30) was significantly lower in pulmonary arterial hypertension patients compared to healthy volunteers (0.3% ± 0.6 versus 1.3% ± 1.1, p = 0.04), all values were within the normal reference range (0–8%). All other thrombelastography parameters were not significantly different between pulmonary arterial hypertension patients and healthy volunteers (p ≥ 0.15 for all). Similarly, alpha2-antiplasmin activity levels were higher in pulmonary arterial hypertension patients compared to healthy volunteers (103.7% ± 13.6 versus 82.6% ± 9.5, p < 0.0001), but all individual values were within the normal range (75–132%). There were no other significant differences in hematologic markers between pulmonary arterial hypertension patients and healthy volunteers (p ≥ 0.07 for all). Sub-group analysis comparing thrombelastography results in patients treated with or without prostacyclin pathway targeted therapies were also non-significant. In conclusion, treated pulmonary arterial hypertension patients do not demonstrate abnormal clotting kinetics or fibrinolysis by thrombelastography.

Association of thromboelastography profile with severity of liver cirrhosis and portal venous system thrombosis

BACKGROUND AND AIM

Hemostasis profile is often complicated in liver cirrhosis. Thromboelastography is a global viscoelastic test recommended by the current practice guideline and consensus. This cross-sectional study aimed to evaluate the association of thromboelastography profile with severity of liver cirrhosis and presence of portal venous system thrombosis (PVST).

METHODS

Overall, 116 and 50 cirrhotic patients were included in the Shenyang and Xi'an cohorts, respectively. Thromboelastography parameters were compared between cirrhotic patients with Child-Pugh class A and B/C, those with and without decompensated events, and those with and without PVST. Hypercoagulability would be considered if at least two of the following thromboelastography parameters were met: shortened reactive time (R), shortened coagulation time (K), increased angle, and increased maximum amplitude (MA).

RESULTS

In the Shenyang cohort, 16 patients had shortened R, of whom seven (43.75%) had prolonged K and 11 (68.75%) decreased MA. In the Xi'an cohort, 24 patients had shortened R, of whom seven (29.17%) had prolonged K and 15 (62.50%) decreased MA. In the Shenyang cohort, the prevalence of hypercoagulability was not significantly different between cirrhotic patients with Child-Pugh class A and B/C (3.85% vs. 6.25%, P = 0.873), those with and without decompensated events (5.49% vs. 4.00%, P = 1.000), and those with and without PVST (4.17% vs. 5.88%, P = 1.000), which were similar to the results obtained in the Xi'an cohort.

CONCLUSION

There is a high rate of discordance between R and other thromboelastography parameters. In addition, hypercoagulability may not be related to more advanced stage of liver cirrhosis or presence of PVST.

Association of thromboelastography profile with severity of liver cirrhosis and portal venous system thrombosis

BACKGROUND AND AIM

Hemostasis profile is often complicated in liver cirrhosis. Thromboelastography is a global viscoelastic test recommended by the current practice guideline and consensus. This cross-sectional study aimed to evaluate the association of thromboelastography profile with severity of liver cirrhosis and presence of portal venous system thrombosis (PVST).

METHODS

Overall, 116 and 50 cirrhotic patients were included in the Shenyang and Xi'an cohorts, respectively. Thromboelastography parameters were compared between cirrhotic patients with Child-Pugh class A and B/C, those with and without decompensated events, and those with and without PVST. Hypercoagulability would be considered if at least two of the following thromboelastography parameters were met: shortened reactive time (R), shortened coagulation time (K), increased angle, and increased maximum amplitude (MA).

RESULTS

In the Shenyang cohort, 16 patients had shortened R, of whom seven (43.75%) had prolonged K and 11 (68.75%) decreased MA. In the Xi'an cohort, 24 patients had shortened R, of whom seven (29.17%) had prolonged K and 15 (62.50%) decreased MA. In the Shenyang cohort, the prevalence of hypercoagulability was not significantly different between cirrhotic patients with Child-Pugh class A and B/C (3.85% vs. 6.25%, P = 0.873), those with and without decompensated events (5.49% vs. 4.00%, P = 1.000), and those with and without PVST (4.17% vs. 5.88%, P = 1.000), which were similar to the results obtained in the Xi'an cohort.

CONCLUSION

There is a high rate of discordance between R and other thromboelastography parameters. In addition, hypercoagulability may not be related to more advanced stage of liver cirrhosis or presence of PVST.

Thrombocytopenia and Hemostatic Changes in Acute and Chronic Liver Disease: Pathophysiology, Clinical and Laboratory Features, and Management

Thrombocytopenia, defined as a platelet count <150,000/μL, is the most common complication of advanced liver disease or cirrhosis with an incidence of up to 75%. A decrease in platelet count can be the first presenting sign and tends to be proportionally related to the severity of hepatic failure. The pathophysiology of thrombocytopenia in liver disease is multifactorial, including (i) splenomegaly and subsequently increased splenic sequestration of circulating platelets, (ii) reduced hepatic synthesis of thrombopoietin with missing stimulation both of megakaryocytopoiesis and thrombocytopoiesis, resulting in diminished platelet production and release from the bone marrow, and (iii) increased platelet destruction or consumption. Among these pathologies, the decrease in thrombopoietin synthesis has been identified as a central mechanism. Two newly licensed oral thrombopoietin mimetics/receptor agonists, avatrombopag and lusutrombopag, are now available for targeted treatment of thrombocytopenia in patients with advanced liver disease, who are undergoing invasive procedures. This review summarizes recent advances in the understanding of defective but at low level rebalanced hemostasis in stable cirrhosis, discusses clinical consequences and persistent controversial issues related to the inherent bleeding risk, and is focused on a risk-adapted management of thrombocytopenia in patients with chronic liver disease, including a restrictive transfusion regimen.

Topical Issues in Diagnosis of Coagulopathies and Prevention of Thromboembolic Complications of Atrial Fibrillation in Patients with Liver Cirrhosis

Nowadays the comorbid pathology of liver cirrhosis and atrial fibrillation has been widely discussed and reported in the literature in the light of recent findings from the study of the effectiveness and safety of anticoagulants in this category of patients. The review is devoted to summarizing the existing data on the comorbid course of these diseases from the point of view of the impact of bleeding and thrombosis on the quality of life and mortality of patients and the possibility of using new methods of diagnosis and prevention of these complications. The purpose of the review is to focus the attention of physicians and researches on the relevance and prevalence of comorbid course of liver cirrhosis and atrial fibrillation, their complications, and discuss the benefits and possibilities of applying global methods of hemostasis assessment and anticoagulants in clinical practice. This article examines the main pathophysiological aspects of «rebalanced hemostasis» theory in liver coagulopathies, its effect on the onset of bleeding and thrombotic events, and considering the clinical benefit of the use of anticoagulants. The disadvantages of traditional coagulation assessment tests compared to the benefits of thromboelastometry (ROTEM) and thromboelastography (TEG), general fulfilling principles and evaluation of their indicators are discussed. Existing research findings on the safety and efficacy of warfarin and direct oral anticoagulants in patients with liver cirrhosis and atrial fibrillation compared with no treatment are highlighted.

Utility of viscoelastic coagulation testing in liver surgery: a systematic review

BACKGROUND

The objective of the current study was to summarize and evaluate all published evidence regarding viscoelastic testing in the field of liver surgery.

METHODS

A systematic search of the literature was performed using Medline/PubMed, Scopus, Cochrane Library Central, Google Scholar, and clinicaltrials.gov databases. The following keywords were used:"Thromboelastography", "Thromboelastometry", "Viscoelastic tests OR testing", "Sonoclot Devices", "Point-of-care tests OR testing", "Coagulation OR Haemostasis OR Hemostasis", "Liver OR Hepatic Surgery", "Cirrhosis."

RESULTS

A total of 12 studies analyzing 348 patients who underwent viscoelastic testing of coagulation during liver surgery for benign or malignant diseases were included; 7 (58.3%) studies reported on the use of thromboelastography (TEG), and 5 (41.7%) reported on rotational thromboelastometry (ROTEM). Viscoelastic testing (TEG and ROTEM) identified normo-, hyper- and hypo-coagulable status in 77% (n = 268/348), 18.4% (n = 64/348), and 4.6% (n = 16/348) of patients, respectively. In contrast, conventional coagulation tests indicated normo-coagulability in 111 patients (34.2% out of 325) and hypo-coagulability in 214 (65.8% out of 325) patients following liver resection. No patient (0% out of 291) experienced postoperative hemorrhage, whereas 5.8% (n = 17/291) experienced postoperative thromboembolic events.

CONCLUSIONS

Global viscoelastic testing may be a reasonable adjunct to conventional coagulation testing to provide a more robust assessment of the coagulation status of patients undergoing liver surgery.

Coagulation States in Patients With Sudden Sensorineural Hearing Loss Evaluated by Thromboelastography

OBJECTIVE

The state of coagulation is controversial in patients with sudden sensorineural hearing loss (SSNHL). We used thromboelastography (TEG) to explore the relationships between blood coagulation parameters and SSNHL pathogenesis and recovery.

STUDY DESIGN

Prospective study.

SETTING

Affiliated Sixth People's Hospital, Shanghai Jiao Tong University.

METHODS

A total of 104 newly diagnosed patients with SSNHL and 29 matched healthy controls were recruited. Hearing assessments, TEG, and conventional coagulation tests (CCTs) were performed, followed by standard treatments and follow-up.

RESULTS

The TEG parameters of patients with SSNHL were in the normal range, but the group exhibited a significantly prolonged kinetic time (K; P = .004) and a smaller angle (P = .003) as compared with the controls. After grouping the patients with SSNHL according to audiograms and comparing them in pairs, we found that the differences were significant only when controls were compared with patients with low-frequency SSNHL (K, P = .023; angle, P = .04) and flat-type SSNHL (K, P = .017; angle, P = .014). Logistic regression analysis showed that neither TEG nor CCT parameters significantly affected hearing improvement after SSNHL treatment.

CONCLUSIONS

Although the K value and angle were significantly increased and significantly reduced, respectively, in the test group as compared with the control group, the state of coagulation in patients with SSNHL was still within the normal range. No CCT or TEG coagulation parameters (except the angle) differed significantly among patients in each group according to hearing recovery status, which suggested that the coagulation status does not determine the prognosis of patients with SSNHL.

New Uses for Thromboelastography and Other Forms of Viscoelastic Monitoring in the Emergency Department: A Narrative Review

Patients frequently visit the emergency department with conditions that place them at risk of worse outcomes when accompanied by coagulopathy. Routine tests of coagulation-prothrombin time, partial thromboplastin time, platelets, and fibrinogen-have shortcomings that limit their use in providing emergency care. One alternative is to investigate coagulation disturbance with viscoelastic monitoring (VEM), a coagulation test that measures the timing and strength of blood clot development in real time. VEM is widely used and studied in cardiac surgery, liver transplant surgery, anesthesia, and trauma. In this article, we review the technique of VEM and the biologic rationale of using it in addition to routine tests of coagulation in emergency clinical situations. Then, we review the evidence (or lack thereof) for using VEM in the diagnosis and treatment of specific conditions. Finally, we describe the limitations of the test and future directions for clinical use and research in emergency medicine.

Viscoelastic Tests as Point-of-Care Tests in the Assessment and Management of Bleeding and Thrombosis in Liver Disease

Viscoelastic point-of-care (VET POC) tests provide a global assessment of hemostasis and have an increasing role in the management of bleeding and blood component delivery across several clinical settings. VET POC tests have a rapid turnaround time, provide a better overall picture of hemostasis, predict bleeding more accurately than conventional coagulation tests, and reduce blood component usage and health care costs. Despite commonly having abnormal conventional coagulation tests, most patients with chronic liver disease have a "rebalanced" hemostasis. However, this hemostatic balance is delicate and these patients are predisposed to both bleeding and thromboembolic events. Over recent years, VET POC tests have been increasingly studied for their potential as better functional tests of hemostasis in liver disease patients. This review provides a background on the most common VET POC tests (thromboelastography and rotational thromboelastometry) and discusses the current evidence for these tests in the prediction and management of bleeding and thrombosis in patients with chronic liver disease, and in liver resection and transplant. With the recent publication of several randomized controlled trials, there is growing evidence that VET POC tests may be used to improve bleeding risk assessment and reduce blood product use in liver disease patients outside of the transplant setting. However, consensus is still lacking regarding the VET POC tests' thresholds that should be used to trigger blood product transfusion. VET POC tests also show promise in predicting thrombosis in patients with liver disease, but further research is needed before they can be used to guide anticoagulant therapy.

Thromboelastography Better Reflects Hemostatic Abnormalities in Cirrhotics Compared With the International Normalized Ratio

GOAL

The goal of this study was to describe potential key differences in thromboelastography (TEG) variables in hospitalized cirrhotics compared with a healthy population, identify patterns of hematologic disturbance with disease progression, and assess the value of traditional tests such as international normalized ratio (INR) and platelet count to determine coagulopathy in cirrhotics.

BACKGROUND

TEG, a functional assay of coagulation, has emerged as a useful tool for predicting bleeding risk in cirrhosis.

STUDY

Hospitalized cirrhotics who received a TEG before any blood products between January 2017 and February 2018 at a liver transplant center were included. Reaction time (r-time), coagulation time (k-time), angle-rate of clot polymerization (α) and maximum clot strength (maximum amplitude) were measured with kaolin-activated citrated blood TEG assays.

RESULTS

A total of 106 cirrhotic patients (Child-Turcotte-Pugh A, B, C; n=25, 25, 56) were identified for comparison against data from 53 healthy controls. TEG parameters in cirrhotics were statistically different from controls. Mean INR and platelet count for all cirrhotics were largely outside the normal reference range, contrary to TEG parameters which demonstrated parameters mostly within the normal reference ranges. The r-time, k-time, and α values in the cirrhotics progressively increased and maximum amplitude values progressively decreased as the liver disease progressed. Regression analysis showed no significant correlations between INR and r-time across any Child-Turcotte-Pugh class (r=0.01, 0.18, 0.23; P=0.95, 0.39, 0.08, respectively).

CONCLUSIONS

Although cirrhotics had TEG parameters within normal ranges, there was a propensity for decreased clot formation as liver function worsened. Importantly, the INR did not correlate with TEG parameters in cirrhotic patients, and given the precarious hemostatic balance in these patients, a TEG may be a better predictor of bleeding risk.

Rotational thrombelastometry (ROTEM) improves hemostasis assessment compared to conventional coagulation test in ACLF and Non-ACLF patients

Background

Patients with liver cirrhosis typically exhibit abnormal coagulation parameters in conventional coagulation tests (CCTs). Rotational thromboelastometry (ROTEM) is a holistic blood coagulation assay. This method provides an insight into the global hemostatic capabilities and has been suggested to provide a better overview of the coagulation system in liver cirrhosis.

Methods

The goal of this study was to examine hemostasis in patients with stable liver cirrhosis (Non-ACLF) and in acute-on-chronic liver failure (ACLF) by CCT and ROTEM including agreement of both tests and the prospective assessment of test performance based on clinical outcomes in ACLF patients. Therefore, ACLF patients were additionally subgrouped by bleeding events. Fifty-five Non-ACLF patients and twenty-two patients with ACLF were analysed in this prospective cohort study.

Results

Coagulation parameters analysed by CCT were outside the normal range in Non-ACLF and ACLF patients, but were significantly more aberrant in ACLF patients. Non-ACLF patients analysed by ROTEM revealed parameters largely within the normal limits, while significantly more ROTEM parameters in ACLF patients were affected. Maximum clot firmness (MCF) was significantly divergent between both patient groups and correlated well with levels of fibrinogen and platelet count. Using Cohen’s Kappa coefficient κ, the strength of agreement between CCT and ROTEM analyses was determined to be fair for Non-ACLF patients and moderate for ACLF patients. Bleeding events occurred significantly more often in ACLF group with significantly reduced A10 and MCF.

Conclusions

For assessing hemostasis in Non-ACLF and ACLF patients the underlying dataset shows advantages of ROTEM over CCT. A10 and MCF represent suitable prognostic parameters in predicting bleeding events in ACLF group.

Thromboelastography in cats with cholestatic liver disease

OBJECTIVES

While thromboelastography (TEG) has helped define a complex state of hemostasis in dogs and humans with hepatobiliary disease, it has not been explored in cats with cholestatic liver disease (CLD). The objective of this study was to describe TEG parameters in cats with CLD and to compare these parameters with conventional plasma-based coagulation tests, white blood cell (WBC) count and biochemical indicators of liver disease grade and severity.

METHODS

Eighteen cats with CLD, defined by a serum bilirubin ⩾3 mg/dl and a greater than two-fold increase in serum alanine aminotransferase (ALT) and/or alkaline phosphatase (ALP) activity, were prospectively enrolled. All cats received vitamin K1 subcutaneously for 24-36 h prior to acquisition of blood for kaolin-activated TEG analysis, prothrombin time (PT) and activated partial thromboplastin time (aPTT). Patient total solids, packed cell volume, platelet count, WBC count, and serum liver enzymes and bilirubin were extracted from the medical record and correlated with coagulation test results.

RESULTS

TEG global clot strength (TEG G) values defined 9/18 (50%), 5/18 (28%) and 4/18 (22%) cats as hypercoagulable, normocoagulable or hypocoagulable, respectively. TEG G was significantly negatively correlated with PT, aPTT and serum ALP activity and positively correlated with total solids. Five cats (5/18, 28%) were hyperfibrinolytic with clot lysis at 60 mins (LY 60) >15.3%. LY 60 was significantly positively correlated with PT.

CONCLUSIONS AND RELEVANCE

By TEG analysis, cholestatic cats replete with vitamin K1 display a variety of coagulation profiles. Indications of synthetic failure (prolonged PT and aPTT) were associated with hypocoagulable and hyperfibrinolytic TEG parameters. High disease activity (serum ALP) was associated with a hypocoagulable state.

Thromboelastography maximum amplitude predicts short-term mortality in patients with hepatitis B virus-related acute-on-chronic liver failure

Patients with hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) exhibit complex hemostatic defects. Thromboelastography (TEG) can be used to reveal global hemostasis in patients with liver disease; however, little is known about the association between TEG and the outcome of patients with HBV-related ACLF. The present study aimed to investigate the value of TEG for predicting 90 day mortality in patients with HBV-related ACLF. A total of 51 patients with HBV-related ACLF, 26 patients with chronic hepatitis B (CHB) and 26 healthy controls (HC) were enrolled in the present study. TEG, standard coagulation tests, routine blood tests, biochemical markers and demographic variables were recorded and assessed for prognostic value. The results indicated that a prolonged reaction and kinetics (K) time, a shortened α angle and a decreased maximum amplitude (MA) and coagulation index (CI) were observed in patients with HBV-related ACLF, compared with CHB and HC subjects. Patients with HBV-related ACLF in the mortality group exhibited a decrease in α angle, MA, lysis at 30 min, CI, fibrinogen and platelet count, and an increase in K time, international normalized ratio (INR) and the model for end-stage liver disease (MELD) score in comparison with the survival group. MA and INR were two independent predictors of 90 day mortality in patients with HBV-related ACLF, with hazard ratios of 0.918 (95% CI, 0.867-0.971; P=0.003) and 3.141 (95% CI, 1.843-5.354; P<0.001) respectively. When predicting 90 day mortality, MA + INR exhibited the highest area under the receiver operating characteristic curve, followed by INR, MELD score and MA. Patients with ACLF and MA ≤51.5 mm exhibited a poorer outcome than those with MA >51.5 mm, as revealed via the Kaplan-Meier analysis. In summary, the findings of the present study suggested that TEG MA was associated with 90 day mortality in patients with HBV-related ACLF, and a combination of MA and INR was superior to MA, INR and MELD score in terms of prognostic value.

A Randomized Control Trial of Thromboelastography-Guided Transfusion in Cirrhosis for High-Risk Invasive Liver-Related Procedures

BACKGROUND AND AIM

Hemostasis in cirrhosis is dynamic and balanced. Thromboelastography (TEG) assesses global coagulation status. We aimed to assess whether TEG-guided blood product transfusions result in lower blood product requirements in patients with cirrhosis undergoing invasive liver-related procedures as compared to the conventional standard of care (SOC).

METHODS

In this open-label, randomized controlled trial, cirrhosis patients with coagulopathy, undergoing invasive liver-related procedures, were randomized to either TEG-guided blood product transfusion or SOC. The primary outcome was difference in the amount of fresh frozen plasma (FFP) and platelet units transfused between the two groups. The secondary outcome was procedure-related bleeding complications within 5 days and any complications until 28 days.

RESULTS

From November 2017 till June 2019, 58 patients were recruited (29: TEG and 29: SOC). Most common procedures performed were percutaneous liver biopsy (n = 48), followed by transjugular intrahepatic portosystemic shunt (n = 2), percutaneous acetic acid injection (n = 2), and transarterial chemoembolization (n = 2). There were no differences in baseline demographics, hemostatic profile, and types of procedures between the two groups. Only nine patients in TEG group received transfusions compared to all patients in SOC (31% vs 100%; P < 0.001). In TEG group, six (20.7%) received FFP (P = 0.753 vs. SOC), two (6.9%) received platelets (P < 0.001 vs. SOC), and 1(3.4%) patient received both FFP and platelet (P ≥ 0.999 vs. SOC) transfusion. None of the patients in either group developed procedure-related bleeding complications until 5 days post-procedure. The complication rates at 28-day follow-up were similar between the groups.

CONCLUSION

TEG-guided blood product transfusion strategy reduces blood product transfusion without increased risk of bleeding in cirrhotic patients undergoing invasive liver-related procedures (CTRI/2017/12/010822).

Tracing the Lines: A Review of Viscoelastography for Emergency Medicine Clinicians

BACKGROUND

Viscoelastography (VE) is an established method to identify coagulopathies in various disease processes. Clinical decisions can be made with real-time tracings and quantitative values at the bedside. Thromboelastography (TEG®) and rotational thromboelastometry (ROTEM®) have been utilized in several disease states with clinical varying success.

OBJECTIVES

This review will summarize the literature and provide recommendations pertaining to major disease processes where VE may be beneficial, including trauma, anticoagulation reversal, liver disease, acute ischemic stroke, and acquired brain injuries.

DISCUSSION

VE has a role in many emergency medicine patients encountered by clinicians. Reduced mortality, decreased blood product utilization, and prognostication ability makes VE an intriguing tool that can be utilized by providers to improve patient care.

CONCLUSION

This review serves as a way for emergency medicine clinicians to utilize VE in their practice and provides an insightful literature overview.

Primary Hemostasis in Chronic Liver Disease and Cirrhosis: What Did We Learn over the Past Decade?

Changes in primary hemostasis have been described in patients with chronic liver disease (CLD) and cirrhosis and are still subject to ongoing debate. Thrombocytopenia is common and multifactorial. Numerous studies also reported platelet dysfunction. In spite of these changes, primary hemostasis seems to be balanced. Patients with CLD and cirrhosis can suffer from both hemorrhagic and thrombotic complications. Variceal bleeding is the major hemorrhagic complication and is mainly determined by high portal pressure. Non portal hypertension-related bleeding due to hemostatic failure is uncommon. Thrombocytopenia can complicate management of invasive procedures in CLD patients. Recently, oral thrombopoietin agonists have been approved to raise platelets before invasive procedures. In this review we aim to bundle literature, published over the past decade, discussing primary hemostasis in CLD and cirrhosis including (1) platelet count and the role of thrombopoietin (TPO) agonists, (2) platelet function tests and markers of platelet activation, (3) von Willebrand factor and (4) global hemostasis tests.

Liver Fibrosis Indices and Outcomes After Primary Intracerebral Hemorrhage

Background and Purpose- Cirrhosis-clinically overt, advanced liver disease-is associated with an increased risk of hemorrhagic stroke and poor stroke outcomes. We sought to investigate whether subclinical liver disease, specifically liver fibrosis, is associated with clinical and radiological outcomes in patients with primary intracerebral hemorrhage. Methods- We performed a retrospective cohort study using data from the Virtual International Stroke Trials Archive-Intracerebral Hemorrhage. We included adult patients with primary intracerebral hemorrhage presenting within 6 hours of symptom onset. We calculated 3 validated fibrosis indices-Aspartate Aminotransferase-Platelet Ratio Index, Fibrosis-4 score, and Nonalcoholic Fatty Liver Disease Fibrosis Score-and modeled them as continuous exposure variables. Primary outcomes were admission hematoma volume and hematoma expansion. Secondary outcomes were mortality, and the composite of major disability or death, at 90 days. We used linear and logistic regression models adjusted for previously established risk factors. Results- Among 432 patients with intracerebral hemorrhage, the mean Aspartate Aminotransferase-Platelet Ratio Index, Fibrosis-4, and Nonalcoholic Fatty Liver Disease Fibrosis Score values on admission reflected intermediate probabilities of fibrosis, whereas standard hepatic assays and coagulation parameters were largely normal. After adjusting for potential confounders, Aspartate Aminotransferase-Platelet Ratio Index was associated with hematoma volume (β, 0.20 [95% CI, 0.04-0.36]), hematoma expansion (odds ratio, 1.6 [95% CI, 1.1-2.3]), and mortality (odds ratio, 1.8 [95% CI, 1.1-2.7]). Fibrosis-4 was also associated with hematoma volume (β, 0.27 [95% CI, 0.07-0.47]), hematoma expansion (odds ratio, 1.9 [95% CI, 1.2-3.0]), and mortality (odds ratio, 2.0 [95% CI, 1.1-3.6]). Nonalcoholic Fatty Liver Disease Fibrosis Score was not associated with any outcome. Indices were not associated with the composite of major disability or death. Conclusions- In patients with largely normal liver chemistries, 2 liver fibrosis indices were associated with admission hematoma volume, hematoma expansion, and mortality after intracerebral hemorrhage.

Viscoelastic Testing in Liver Disease

Long thought to be hypocoagulable, new evidence suggests cirrhosis patients have "rebalanced" coagulation in the setting of decreased synthesis of both pro- and anti-coagulant factors. Traditional testing like PT/INR reflects only the decreased synthesis of pro-coagulant factors and thus does not correspond to bleeding or clotting risk in this population. In this review, we discuss the use of viscoelastic testing (VET), an assay of global hemostasis in cirrhosis patients. We describe the technique and interpretation of commercially available VET and assess the application of VET in both transplant and non-transplant cirrhosis populations. VET largely correlates well with traditional testing including platelet count and fibrinogen level, however, is potentially less accurate in patients with low fibrinogen levels. VET may be useful in identifying patients at higher risk of hypercoagulable complications post-transplant and reflects changes in hemostasis in decompensated patients. While VET has been associated with decreased transfusión support in multiple studies, the lack of bleeding in patients who avoided prophylactic transfusion suggests a "rescue" rather than prophylactic approach to transfusion may be ideal and further studies with a "rescue" arm are needed. Additional prospective studies of VET should include clinically relevant endpoints of bleeding and thrombosis.

Bleeding Risk with Invasive Procedures in Patients with Cirrhosis and Coagulopathy

PURPOSE OF REVIEW

Previous perceptions of cirrhosis as a hypocoagulable state have resulted in empirical blood product transfusions prior to invasive procedures. We evaluate procedure-related bleeding risks in patients with cirrhosis, assess the utility of conventional and newer global coagulation tests, and explore evidence surrounding prophylactic transfusion strategies.

RECENT FINDINGS

Recent literature supports the concept of a rebalanced, albeit fragile, haemostasis equilibrium in cirrhosis, with a potential hypercoagulable tendency in stable patients. Standard coagulation tests provide a poor reflection of bleeding risks and yet are relied upon for transfusion thresholds. Consequently, a sizeable proportion of patients receive unnecessary blood products. The role of viscoelastic tests to guide transfusions requires further evaluation. In stable cirrhotic patients, procedure-related bleeding rates appear low. Prophylactic transfusion strategies based on arbitrary thresholds lack evidence of clinical benefit. There is a pressing need for point-of-care coagulation tests that represent the complex coagulopathy of cirrhosis and well-powered randomised controlled trials to develop evidence-based pre-procedure transfusion guidelines.