Thromboelastography identifies hypercoagulablilty and predicts thromboembolic complications in patients with prostate cancer

Intraprostatic Injection of Tranexamic Acid Decrease Blood Loss During Monopolar Transurethral Resection of the Prostate: A Randomized Controlled Clinical Trial

OBJECTIVE

To assess the role of intraprostatic injection of tranexamic acid (TXA) in reducing blood loss during transurethral resection of the prostate (TURP).

METHODS

We conducted a randomized, controlled, double-blind trial involving 60 patients with benign prostatic hyperplasia aged 50-85years, undergoing monopolar TURP. Patients' prostatic weights ranged from 50 to 80 g. They were divided equally into two groups: group I received an intraprostatic injection of 1 g of TXA (Cyklokapron) dissolved in 50 mL of 0.9 % saline at multiple sites, while group II (control) received a 60 mL saline injection. Comprehensive clinical assessments and standard laboratory tests, including screenings for TXA hypersensitivity, were performed for all patients.

RESULTS

Group I exhibited significantly lower intraoperative blood loss and hemoglobin concentration in irrigation fluid immediately postsurgery and at the 6-hour postoperative mark compared to group II (P < .05). Coagulation parameters-activated partial thromboplastin time, prothrombin time, fibrinogen level, and thrombin clotting time-showed no significant differences between the groups preoperatively or at 6 and 24 hours postoperatively. No thromboembolic events or other complications were reported in either group.

CONCLUSION

The intraprostatic injection of TXA during monopolar TURP is safe, with minimal adverse effects, and effectively reduces blood loss.

REGISTRATION

The study was registered on ClinicalTrials.gov No (ID: NCT05913466).

Hypercoagulable state and effect of low-molecular-weight heparin prophylaxis on coagulation after lung cancer resection: results from thrombo-elastography

BACKGROUND

Lung cancer patients undergoing surgery are at increased risk for Venous thromboembolism (VTE). We monitored changes in perioperative coagulation status through Thrombo-elastography (TEG), and monitored the anticoagulant effect of low molecular weight heparin through TEG for the first time.

METHODS

From July 2019 to January 2020, 207 patients receiving curative surgery were retrospectively screened. and 23 patients were excluded because they did not meet the inclusion criteria. Blood samples were required at three time points (prior to, the first and third day after surgery). Some patients were administrated nadroparin calcium daily from the first day after surgery. Repeated measures ANOVA and Chi-square test were used to analyze the coagulation states variation. To balance the confounders, propensity score matching (PSM) was used to determine the differences of coagulation states between patients with or without Low-molecular-weight heparin (LMWH) prophylaxis.

RESULTS

In 184 patients, TEG parameters displayed significant procoagulant changes after lung surgery but conventional coagulation tests exhibited paradoxical trends. There were 6.5% (12/184) of patients identified as hypercoagulability before surgery. According to TEG results, the proportion of patients with hypercoagulability rose from 21.7% to 25% postoperatively, but more were classified into platelet or mixed hypercoagulability at third day compared with that at first day (3.8% vs 14.1%, P < 0.001). By PSM analysis, there were no significant differences in the proportion of hypercoagulable patients postoperatively between chemoprophylactic and nonprophylactic group.

CONCLUSIONS

TEG was eligible to distinguish changing states of hypercoagulability postoperatively and indicate the role of platelet in blood hypercoagulability. Administration of postoperative LMWH prophylaxis showed little mitigation on hypercoagulable states.

Analyzing venous thromboembolism risk in malignant tumors: thromboelastogram and coagulation factors study

Aim: This retrospective clinical study was designed to examine the predictive value of thromboelastography (TEG) combined with coagulation function for venous thromboembolism (VTE) in hospitalized patients with cancer. Materials & methods: Among 215 patients admitted between May 2020 and January 2022, 39 (18.14%) were diagnosed with VTE during hospitalization. Results: Significant differences were found in D-dimer, ATIII and TEG parameters (maximum amplitude and coagulation index) between VTE-positive and VTE-negative patients (p < 0.05). Multivariate analysis revealed tumor node metastasis stage, concomitant infection, smoking history and D-dimer as independently associated with VTE. The constructed model and D-dimer areas under the curve were 0.809 and 0.764, respectively. Conclusion: TEG parameters were not significantly predictive indicators for VTE, with D-dimer remaining a key predictor.

Incidence and risk factors of venous and arterial thromboembolic events among patients with ovarian cancer- data from a large Canadian database

OBJECTIVES

To determine the incidence of thromboembolic events (TEEs) in ovarian cancer patients and to identify risk factors that are significantly associated with the development of venous thromboembolism (VTE), arterial thromboembolism (ATE), or overall TEEs in this population.

METHODS

This is a retrospective cohort study of 4491 patients with epithelial ovarian cancer identified in the British Columbia cancer registry between 1996 and 2017. The presence of TEEs and risk factors were identified in administrative health records from fee-for-service provider visits and hospital data using ICD-9-CM and ICD-10-CM billing codes. Statistical analysis was performed using Chi-squared test and Fischer's exact test.

RESULTS

Of 4491 patients with epithelial ovarian cancer included in this study, 1.74% experienced ATE and (9.44%) experienced VTE. There was a significant association found between the occurrence of TEEs and all-cause mortality. Sepsis was significantly associated with both venous and arterial thromboembolism. The top three risk factors for arterial thromboembolism included peripheral vascular disease (PVD), open wound, and aneurysm.

CONCLUSIONS

Risk factors predictive of thrombosis in ovarian cancer patients are not consistent between ATE and VTE, thus thrombotic events should not be combined for analysis. Differential thrombosis risk assessment is needed to improve prevention strategies and guide thromboprophylaxis for these patients.

Investigation of Pulmonary Saddle Embolism Caused by Metastasis-Induced Hypercoagulability Originating From Pancreatic Cancer

An adult male cadaver, approximately 60 years of age, was dissected as part of an eight-week didactic course. It was found that the subject had evidence of pancreatic cancer with signs of metastasis as well as significant bilateral pulmonary artery clotting. In particular, a saddle embolism was observed, and the cause of death was listed as sudden pulmonary failure. Malignant tumors are often accompanied by hypercoagulable states and increased risk of thromboembolism. Because the clots showed lines of Zahn on histology, we can infer that this hypercoagulable state preceded death and may have been related to the presence of pancreatic carcinoma. There are few recorded cases of pulmonary saddle embolism being the fatal event in cases of underlying pancreatic cancer. The extensive clotting observed in the inferior vena cava and pulmonary arteries demonstrates to clinicians that patients, especially those with pancreatic cancer, are at higher risk for thromboembolic events. This case report also serves as a reminder that instances of pulmonary failure or sudden death because of pulmonary saddle embolism may be caused by underlying visceral neoplasms, such as pancreatic cancer.

Assessing hypercoagulability and VTE risk using thromboelastography and Khorana score in women with cancers receiving chemotherapy

Venous thromboembolism (VTE) is a common occurrence in cancer and chemotherapy increases thrombosis risk. Current risk assessment models such as the Khorana score (KS) and its modifications have limitations in female cancers. We assessed the coagulation profile of a group of women cancer patients under chemotherapy using thromboelastography (TEG) to determine if this can inform VTE risk assessment. Cancer patients who planned to receive chemotherapy were recruited. Baseline demographics, cancer data, BMI, Khorana Score (KS), and VTE risk factors were recorded and patients were followed for 6 months, for any thrombotic events. A total of 36 patients aged 35-85 (18 breast, 11 endometrial, 7 ovarian cancer) were evaluated. Hypercoagulability was detected in 63% of patients post-chemo cycle 1 and 75% post-cycle 2, with a significant increase in MA (maximum amplitude) and CI (clotting index), reduction in R (reaction time), K (clot kinetics), and LY30 (lysis time after 30 min of MA). KS showed only 7% of patients were high risk, 23% were low, and 70% were intermediate risk. MA and CI significantly increased in patients with intermediate and high-risk KS when compared with the low-risk patients and MA was positively correlated with KS. Five patients developed actual VTE; 100% of the tested ones were hypercoagulable either post-cycle 1 or 2 and 80% were KS intermediate risk. TEG is a hypercoagulability marker and TEG-MA and CI can potentially assess VTE risk. Larger studies are needed to assess the utility of TEG as an adjuvant to KS to better predict VTE in specific female cancers.

Applications of Viscoelastic Testing in Breast Cancer Patients: A Systematic Review Focusing on Hypercoagulability and Free Flap Thrombosis

Viscoelastic testing is a clinically available method to assess hypercoagulability. This systematic review aims to provide a comprehensive overview of the existing literature and the potential use of such testing in patients with breast cancer. A systematic literature search for studies investigating the application of viscoelastic testing for patients with breast cancer was conducted. Studies were included as long as they were original, peer-reviewed, and in the English language. Studies were excluded if they were review articles, did not include breast cancer patients, or if the full text was unavailable. This review identified 10 articles that met the inclusion criteria. Two of the studies utilized rotational thromboelastometry, and an additional four studies used thromboelastography, to assess hypercoagulability in patients with breast cancer. Three of the identified articles discussed the use of thromboelastometry in free flap breast reconstruction for patients with breast cancer. One study was a retrospective chart review looking at thromboelastography and microsurgical breast reconstruction. Current literature regarding the application of viscoelastic testing in breast cancer and free flap breast reconstruction is limited, with no randomized trials thus far. However, some studies suggest that there may be potential utility in viscoelastic testing to assess risk for thromboembolism in breast cancer patients, and future research in this area is warranted.

Nomogram model combined thrombelastography for venous thromboembolism risk in patients undergoing lung cancer surgery

Background: The aim of this study was to develop a nomogram model in combination with thromboelastography (TEG) to predict the development of venous thromboembolism (VTE) after lung cancer surgery. Methods: The data of 502 patients who underwent surgical treatment for lung cancer from December 2020 to December 2022 were retrospectively analyzed. Patients were then randomized into training and validation groups. Univariate and multivariate logistic regression analyses were carried out in the training group and independent risk factors were included in the nomogram to construct risk prediction models. The predictive capability of the model was assessed by the consistency index (C-index), receiver operating characteristic curves (ROC), the calibration plot and decision curve analysis (DCA). Results: The nomogram risk prediction model comprised of the following five independent risk factors: age, operation time, forced expiratory volume in one second and postoperative TEG parameters k value(K) and reaction time(R). The nomogram model demonstrated better predictive power than the modified Caprini model, with the C-index being greater. The calibration curve verified the consistency of nomogram between the two groups. Furthermore, DCA demonstrated the clinical value and potential for practical application of the nomogram. Conclusion: This study is the first to combine TEG and clinical risk factors to construct a nomogram to predict the occurrence of VTE in patients after lung cancer surgery. This model provides a simple and user-friendly method to assess the probability of VTE in postoperative lung cancer patients, enabling clinicians to develop individualized preventive anticoagulation strategies to reduce the incidence of such complications.

Viscoelastic Testing Methods

Viscoelastic testing methods examine the real-time formation of a clot in a whole blood sample, and include thromboelastography (TEG), rotational thromboelastometry (ROTEM), and several other testing platforms. They allow for concurrent assessment of multiple aspects of clotting, including plasmatic coagulation factors, platelets, fibrinogen, and the fibrinolytic pathway. This testing is rapid and may be performed at the point-of-care, allowing for prompt identification of coagulopathies to guide focused and rational administration of blood products as well as the identification of anticoagulant effect. With recent industry progression towards user-friendly, cartridge-based, portable instruments, viscoelastic testing has emerged in the 21st century as a powerful tool to guide blood transfusions in the bleeding patient, and to identify and treat both bleeding and thrombotic conditions in many operative settings, including trauma surgery, liver transplant surgery, cardiac surgery, and obstetrics. In these settings, the use of transfusion algorithms guided by viscoelastic testing data has resulted in widespread improvements in patient blood management as well as modest improvements in select patient outcomes. To address the increasingly wide adoption of viscoelastic methods and the growing number of medical and laboratory personnel tasked with implementing, performing, and interpreting these methods, this chapter provides an overview of the history, physiology, and technology behind viscoelastic testing, as well as a practical review of its clinical utility and current evidence supporting its use. Also included is a review of testing limitations and the contextual role played by viscoelastic methods among all coagulation laboratory testing.

Tissue factor positive microparticles as a biomarker for increased risk of breast cancer-associated thrombosis: a mini review

PURPOSE OF REVIEW

Cancer-associated thrombosis (CAT), such as venous thromboembolism (VTE), is a frequent complication in cancer patients, resulting in poor prognosis. Breast cancer is not highly thrombogenic but is highly prevalent, resulting in increased VTE cases. Many cancers express tissue factor (TF), a glycoprotein that triggers coagulation. The cancer cells were shown to express and release substantial amounts of TF-positive microparticles (MPTF), associated with a prothrombotic state. This narrative review evaluated the current use of the procoagulant MPTF as a biomarker for thrombosis risk in breast cancer.

RECENT FINDINGS

Tumors of epithelial origin with elevated TF expression have been associated with increased VTE incidence. Thus, studies have affirmed the use of MPTF biomarkers for VTE risk in many cancers. Patients with metastatic breast cancer and CAT were found to exhibit elevated procoagulant microparticles in vitro, due to TF expression. The silencing of TF was associated with decreased microparticle release in breast carcinoma cell lines, associated with decreased coagulation.

SUMMARY

CAT is a multifactorial condition, with several various underlying diseases. It is proposed that MPTF may be an effective biomarker for thrombosis risk in breast cancer patients but requires a more systemic evaluation utilizing standardized quantification methods.

The investigation on the hypercoagulability of hepatocellular carcinoma-related cerebral infarction with thromboelastography

AIM

To investigate the hypercoagulability of hepatocellular carcinoma (HCC)-related cerebral infarction (HCRCI) with thromboelastography (TEG).

METHODS

A multicenter prospective study was conducted in HCRCI patients, HCC patients without cerebral infarction, and acute cerebral infarction (ACI) patients without HCC between January 2016 and December 2019. TEG parameters and laboratory and clinical data were collected and compared among the three groups. To confirm the independent risk factors of HCRCI, multivariate analyses were conducted. Receiver operating characteristic (ROC) curves were utilized to evaluate the area under the curve (AUC) plotted by each independent risk factor.

RESULTS

There were 38 patients recruited in the HCRCI group, and 152 patients were recruited to the HCC group and the ACI group. The levels of plasma neutrophil count, D-dimer, α-fetoprotein (AFP), carcinoembryonic antigen, and maximum amplitude (MA)-a parameter of TEG-were significantly higher in the HCRCI group than HCC and ACI groups. Multivariate logistic regression analysis showed that increased neutrophile count, D-dimer, AFP, and MA were independently associated with HCRCI. ROC curve analysis showed first that AUC of MA for HCRCI was .875, which was larger than the other risk factors, and second that the optimal cutoff value for MA was 61.35, with a sensitivity of 89.50% and specificity of 66.40%.

CONCLUSION

It was suggested that TEG disclosed that the pathogenesis of HCRIC is exactly related to the hypercoagulability. And with a cutoff value of MA equaling to 61.35, TEG facilitates clinicians to identify HCC patients at high risk of HCRIC.

Hypercoagulability and Thrombosis Risk in Prostate Cancer: The Role of Thromboelastography

Thrombosis is one of the leading causes of death in cancer. Cancer-induced hypercoagulable state contributes to thrombosis and is often overlooked. Prostate cancer may not be of high thrombogenic potential compared with other cancers, but its high prevalence brings it into focus. Pathological evidence for venous thromboembolisms (VTEs) in prostate cancer exists. Factors such as age, comorbidities, and therapies increase the VTE risk further. There is a need to systematically identify the risk of VTE in regard to patient-, cancer-, and treatment-related factors to risk stratify patients for better-targeted and individualized strategies to prevent VTE. Sensitive tests to enable such risk assessment are urgently required. There is sufficient evidence for the utility of thromboelastography (TEG) in cancer, but it is not yet part of the clinic and there is only limited data on the use of TEG in prostate cancer. One study revealed that compared with age-matched controls, 68.8% of prostate cancer patients demonstrated hypercoagulable TEG parameters. The absence of clinical guidelines is a limiting factor in TEG use in the cancer population. Cancer heterogeneity and the unique cancer-specific microenvironment in each patient, as well as determining the hypercoagulable state in each patient, are added limitations. The way forward is to combine efforts to design large multicenter studies to investigate the utility and clinical effectiveness of TEG in cancer and establish longitudinal studies to understand the link between hypercoagulable state and development of thrombosis. There is also a need to study low thrombogenic cancers as well as high thrombogenic ones. Awareness among clinicians and understanding of test applicability and interpretation are needed. Finally, expert discussion is critical to identify the investigation priorities.

What Proportion of Patients With Musculoskeletal Tumors Demonstrate Thromboelastographic Markers of Hypercoagulability? A Pilot Study

BACKGROUND

Thromboelastography (TEG) is a point-of-care venipuncture test that measures the elasticity and strength of a clot formed from a patient's blood, providing a more comprehensive analysis of a patient's coagulation status than conventional measures of coagulation. TEG includes four primary markers: R-time, which measures the time to clot initiation and is a proxy for platelet function; K-value, which measures the time for said clot to reach an amplitude of 20 mm and is a proxy for fibrin cross-linking; maximum amplitude (MA), which measures the clot's maximum amplitude and is a proxy for platelet aggregation; and LY30, which measures the percentage of clot lysis 30 minutes after reaching the MA and is a proxy for fibrinolysis. Analysis of TEG-derived coagulation profiles may help surgeons identify patient-related and disease-related factors associated with hypercoagulability. TEG-derived coagulation profiles of patients with musculoskeletal oncology conditions have yet to be characterized.

QUESTIONS/PURPOSES

(1) What TEG coagulation profile markers are most frequently aberrant in patients with musculoskeletal oncology conditions presenting for surgery? (2) Among patients with musculoskeletal oncology conditions presenting for surgery, what factors are more common in those with TEG-defined hypercoagulability? (3) Do patients with musculoskeletal oncology conditions with preoperative TEG-defined hypercoagulability have a higher postoperative incidence of clinically symptomatic venous thromboembolism (VTE) than those with a normal TEG profile?

METHODS

In this retrospective, pilot study, we analyzed preoperatively drawn TEG assays on 52 patients with either primary bone sarcoma, soft tissue sarcoma, or metastatic disease to bone who were scheduled to undergo either tumor resection or nail stabilization. Between January 2020 and December 2021, our orthopaedic oncology service treated 410 patients in total. Of these, 13% (53 of 410 patients) had preoperatively drawn TEG assays. TEG assays were collected preincision as part of a division initiative to integrate the assay into a clinical care protocol for patients with primary bone or soft tissue sarcoma or metastatic disease to bone. Unfortunately, failures to adequately communicate this to our anesthesia colleagues on a consistent basis resulted in a low overall rate of assay draws from eligible patients. One patient on therapeutic anticoagulation preoperatively for the treatment of active VTE was excluded, leaving 52 patients eligible for analysis. We did not exclude patients taking prophylactic antiplatelet therapy preoperatively. All patients were followed for a minimum of 6 weeks postoperatively. We analyzed factors (age, sex, tumor location, presence of metastases, and soft tissue versus bony disease) in reference to hypercoagulability, defined as a TEG result indicating supranormal clot formation (for example, reduced R-time, reduced K-value, or increased MA). Patients with clinical concern for deep vein thrombosis (DVT) (typically painful swelling of the affected extremity) or pulmonary embolism (typically by dyspnea, tachycardia, and/or chest pain) underwent duplex ultrasonography or chest CT angiography, respectively, to confirm the diagnosis. Categorical variables were analyzed via a Pearson chi-square test and continuous variables were analyzed via t-test, with significance defined at α = 0.05.

RESULTS

Overall, 60% (31 of 52) of patients had an abnormal preoperative TEG result. All abnormal TEG assay results demonstrated markers of hypercoagulability. The most frequent aberration was a reduced K-value (40% [21 of 52] of patients), followed by reduced R-time (35% [18 of 52] of patients) and increased MA (17% [9 of 52] of patients). The mean ± SD TEG markers were R-time: 4.3 ± 1.0, K-value: 1.2 ± 0.4, MA: 66.9 ± 7.7, and LY30: 1.0 ± 1.2. There was no association between hypercoagulability and tumor location or metastatic stage. The mean age of patients with TEG-defined hypercoagulability was higher than those with a normal TEG profile (44 ± 23 years versus 59 ± 17 years, mean difference 15 [95% confidence interval (CI) 4 to 26]; p = 0.01). In addition, female patients were more likely than male patients to demonstrate TEG-defined hypercoagulability (75% [18 of 24] of female patients versus 46% [13 of 28] of male patients, OR 3.5 [95% CI 1 to 11]; p = 0.04) as were those with soft tissue disease (as opposed to bony) (77% [20 of 26] of patients with soft tissue versus 42% [11 of 26] of patients with bony disease, OR 4.6 [95% CI 1 to 15]; p = 0.01). Postoperatively, symptomatic DVT developed in 10% (5 of 52; four proximal DVTs, one distal DVT) of patients, and no patients developed symptomatic pulmonary embolism. Patients with preoperative TEG-defined hypercoagulability were more likely to be diagnosed with symptomatic postoperative DVT than patients with normal TEG profiles (16% [5 of 31] of patients with TEG-defined hypercoagulability versus 0% [0 of 21] of patients with normal TEG profiles; p = 0.05). No patients with normal preoperative TEG profiles had clinically symptomatic VTE.

CONCLUSION

Patients with musculoskeletal tumors are at high risk of hypercoagulability as determined by TEG. Patients who were older, female, and had soft tissue disease (as opposed to bony) were more likely to demonstrate TEG-defined hypercoagulability in our cohort. The postoperative VTE incidence was higher among patients with preoperative TEG-defined hypercoagulability. The findings in this pilot study warrant further investigation, perhaps through multicenter collaboration that can provide a sufficient cohort to power a robust, multivariable analysis, better characterizing patient and disease risk factors for hypercoagulability. Patients with TEG-defined hypercoagulability may warrant a higher index of suspicion for VTE and careful thought regarding their chemoprophylaxis regimen. Future work may also evaluate the effectiveness of TEG-guided chemoprophylaxis, as results of the assay may inform selection of antiplatelet versus anticoagulant agent.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The Hypercoagulable Profile of Patients with Bone Tumors: A Pilot Observational Study Using Rotational Thromboelastometry

Introduction: A detailed evaluation of the malignancy-associated coagulopathy (MAC) in surgical patients with bone tumors may allow for more effective thromboprophylactic measures. The purpose of this study was to assess the perioperative hemostatic changes in patients with bone tumors, using rotational thromboelastometry (ROTEM). Methods: An observational study was performed, including 50 patients with bone tumors who underwent oncologic resection and 30 healthy controls, matched for age and gender. The preoperative and postoperative laboratory evaluation of coagulation in both groups included conventional coagulation tests and a ROTEM analysis. The results of the conventional coagulation tests and the ROTEM analysis were compared between the two groups. Results: The results of the conventional coagulation tests were comparable between the tumor patients and the healthy controls. However, compared to the healthy adults, the tumor patients had lower CT (p < 0.001) and CFT (p < 0.001) values suggesting a rapid induction of the coagulation cascade, elevated A10 (p < 0.001) and MCF (p < 0.001) values indicating a higher clot strength and platelet activation, and elevated LI60 (p < 0.001) values indicating hypofibrinolysis in patients with bone tumors. The multiple linear regression analysis (controlling for potential confounding factors) confirmed the independent association of bone tumors with these hemostatic changes. Conclusions: Our results support the advantageous use of a ROTEM in patients with bone tumors over conventional coagulation tests because the qualitative changes in the hemostatic profile of these patients that can be detected by a ROTEM analysis cannot be identified by conventional tests. The ROTEM results indicate that the hypercoagulable state in patients with bone tumors is caused by the malignancy-associated activation of the coagulation cascade, platelet activation, and hypofibrinolysis.

Ex vivo Vitamin D supplementation improves viscoelastic profiles in prostate cancer patients

BACKGROUND: Increased risk of thromboembolic events is associated with prostate cancer, specifically linked to activation of tissue factor. Vitamin D has potential anticoagulant effects by the downregulation of tissue factor expression. OBJECTIVES: To evaluate the effects on clot formation, the morphological and viscoelastic profiles of prostate cancer patients, before and after ex vivo supplementation of Vitamin D was studied. METHODS: Participants were recruited into a metastatic, non-metastatic and reference group. Whole blood samples were treated ex vivo with a dose of 0.5μg/kg Calcitriol. Clot kinetics were assessed using Thromboelastography ®. Morphology of the blood components were studied using scanning electron microscopy (SEM). RESULTS: Results from the Thromboelastography ® and SEM indicated no major differences between the non-metastatic group before and after treatment compared to the reference group. The Thromboelastography ® showed that the metastatic group had an increased viscoelastic profile relating to a hypercoagulable state. Visible changes with regards to platelet activation and fibrin morphology were demonstrated with SEM analysis of the metastatic group. The viscoelastic and morphological properties for the non-metastatic group after treatment improved to be comparable to the reference group. CONCLUSION: Vitamin D supplementation may lead to a more favorable viscoelastic profile, with less dangerous clots forming.

Questions about COVID-19 associated coagulopathy: possible answers from the viscoelastic tests

Abnormal coagulation parameters are often observed in patients with coronavirus disease 2019 (COVID-19) and the severity of derangement has been associated with a poor prognosis. The COVID-19 associated coagulopathy (CAC) displays unique features that include a high risk of developing thromboembolic complications. Viscoelastic tests (VETs), such as thromboelastometry (ROTEM), thromboelastography (TEG) and Quantra Hemostasis Analyzer (Quantra), provide "dynamic" data on clot formation and dissolution; they are used in different critical care settings, both in hemorrhagic and in thrombotic conditions. In patients with severe COVID-19 infection VETs can supply to clinicians more information about the CAC, identifying the presence of hypercoagulable and hypofibrinolysis states. In the last year, many studies have proposed to explain the underlying characteristics of CAC; however, there remain many unanswered questions. We tried to address some of the important queries about CAC through VETs analysis.

Perioperative Viscoelastic Assay Use for Monitoring Coagulation Among US Liver Transplantation Centers

BACKGROUND

Viscoelastic assay has been used in liver transplantation since 1985 and shown to be beneficial in detecting coagulopathy and to guide transfusion. The objective of this study was to review and evaluate the current uses of viscoelastic assay among US liver transplantation programs.

METHODS

Anesthesia program directors at all 137 liver transplantation centers in the United States were contacted via email and asked to complete a 21-item survey. The primary outcome measure was the percentage of viscoelastic assay used in the perioperative management of liver transplantation. Secondary outcome measures were institutional demographics, physician training level, and device demographics.

RESULTS

Sixty-one of 137 (46%) centers responded. Liver transplantations were performed in the university setting at 48 of the 61 centers (77%), with a modal value of 11 to 50 liver transplantations a year and 74% in adult patients only. Most of the institutions (n = 57, 92%) had access to either rotational thromboelastometry or thrombelastography during liver transplantation. Most centers (n = 54; 87%) also used viscoelastic monitoring routinely (>60% of the time), including 42 (67.7%) that always used viscoelastic assay intraoperatively during liver transplantation. Thirty-five centers (59%) used it preoperatively, and 51 (84%) used it postoperatively. Most viscoelastic assay users (68%) learned how to use it through self-education and 10.5% learned during their fellowship or from a superuser or colleagues.

CONCLUSION

Currently, viscoelastic monitoring is widely available and routinely used in most US liver transplantation centers regardless of university or private practice setting, but training in it is limited. Only 21.1% of respondents reported that they received any type of official training in viscoelastic assay interpretation.

Viscoelastic testing in oncology patients (including for the diagnosis of fibrinolysis): Review of existing evidence, technology comparison, and clinical utility

The quantification of the coagulopathic state associated with oncologic and hematologic diseases is imperfectly assessed by common coagulation tests such as prothrombin time, activated partial thromboplastin time, fibrinogen levels, and platelet count. These tests provide a static representation of a component of hemostatic integrity, presenting an incomplete picture of coagulation in these patients. Viscoelastic tests (VETs), such as rotational thromboelastometry (ROTEM) and thromboelastography (TEG), as whole blood analyses, provide data related to the cumulative effects of blood components and all stages of the coagulation and fibrinolytic processes. The utility of VETs has been demonstrated since the late 1960s in guiding blood component therapy for patients undergoing liver transplantation. Since then, the scope of viscoelastic testing has expanded to become routinely used for cardiac surgery, obstetrics, and trauma. In the past decade, VETs' expanded usage has been most significant in trauma resuscitation. However, use of VETs for patients with malignancy-associated coagulopathy (MAC) and hematologic malignancies is increasing. For the purposes of this narrative review, we discuss the similarities between trauma-induced coagulopathy (TIC) and MAC. These similarities center on the thrombomodulin-thrombin complex as it switches between the thrombin-activatable fibrinolysis inhibitor coagulation pathway and activating the protein C anticoagulation pathway. This produces a spectrum of coagulopathy and fibrinolytic alterations ranging from shutdown to hyperfibrinolysis that are common to TIC, MAC, and hematologic malignancies. There is expanding literature regarding the utility of TEG and ROTEM to describe the hemostatic integrity of patients with oncologic and hematologic conditions, which we review here.

Hypercoagulability in Septic Shock Patients With Thrombocytopenia

BACKGROUND

Despite thrombocytopenia, patients with sepsis often experience hypercoagulability. However, limited information is available on the prevalence and effect of hypercoagulability in patients with sepsis-induced thrombocytopenia. Hence, we evaluated the prevalence of hypercoagulability and the association between hypercoagulability and clinical outcomes in septic shock patients with thrombocytopenia.

METHODS

Thromboelastography (TEG) was performed prospectively in 1294 patients with septic shock at the emergency department (ED) between January 2016 and December 2019. After excluding 405 patients who did not require resuscitation, refused enrollment, or developed septic shock after ED presentation, 889 patients were included. We defined thrombocytopenia as an admission platelet count lower than 150,000/µl according to SOFA score. We defined hypocoagulability and hypercoagulability as coagulation index (CI)< -3 and >3 on TEG, respectively.

RESULTS

Of the 889 septic shock patients (mean age 65.6 ± 12.7 years, 58.6% male), 473 (53.2%) had thrombocytopenia. Eighty-five (18.0%) patients showed hypercoagulable TEG and73 (15.4%) patients showed hypocoagulable TEG. The hypercoagulable TEG group had a significantly higher fibrinogen level and a lower 28-day mortality rate than the normal and hypocoagulable TEG groups (518 vs. 347 and 315 mg/dL; 7.1% vs. 21.1% and 36.8%, P < 0.01, respectively). In multivariate analysis, hypercoagulable TEG was associated with a decreased mortality rate (odds ratio: 0.395; 95% confidence interval, 0.162-0.965).

CONCLUSIONS

In septic shock patients with thrombocytopenia, hypercoagulability was not uncommon. TEG can quickly distinguish the hypercoagulability and hypocoagulability states and serve as a valuable tool for evaluating the degree and risk in septic shock patients with thrombocytopenia.

The Role of TEG Analysis in Patients with COVID-19-Associated Coagulopathy: A Systematic Review

Coronavirus disease 2019 (COVID-19)-associated coagulopathy (CAC), characterized by hypercoagulability and an increased risk of thrombotic complications, is an important consideration in the management of patients with COVID-19. As COVID-19 is a new disease, no standard of care for the diagnosis or management of its associated coagulopathy is yet established. Whole blood viscoelastic tests, such as thromboelastography (TEG^® hemostasis analyzer), analyze whole blood to provide a complete overview of the coagulation status. We conducted a systematic review of thromboelastography for management of patients with COVID-19, using MEDLINE (PubMed) and Cochrane databases. TEG^® parameter measurements and clinical outcomes data were extracted for analysis. Our review found 15 publications, with overall results showing thromboelastography can identify and assess a hypercoagulable state in patients with COVID-19. Furthermore, utilization of thromboelastography in this patient population was shown to predict thrombotic complications. The benefits of thromboelastography presented here, in addition to advantages compared with laboratory coagulation tests, position thromboelastography as an important opportunity for optimizing diagnosis of CAC and improving patient management in COVID-19. Given that the benefits of thromboelastography have already been demonstrated in several other clinical applications, we anticipate that clinical data from future studies in patients with COVID-19 will further elucidate the optimal use of thromboelastography in this patient population.

Utility of Thromboelastography to Identify Hypercoagulability in Lung Cancer Related Ischemic Stroke Patients

Lung cancer related hypercoagulability could increase the risk of ischemic stroke. Routine coagulation tests may have limited capacity in evaluating hypercoagulability. The aim of this study was to investigate the ability of thromboelastography (TEG) in the identification of hypercoagulability in patients with lung cancer and cryptogenic ischemic stroke (LCIS). Between January 2016 and December 2018, whole citrated blood from LCIS patients (n = 35) and age- and gender-matched lung cancer patients and healthy volunteers were used for TEG and routine coagulation tests. The coagulation indicator and clinical data were compared among the 3 groups. There were 27/35 (77.14%) on TEG and 18/35 (51.43%) on routine coagulation tests of LCIS patients who had evidence of hypercoagulability. The detection rate of hypercoagulability by TEG in LCIS patients was higher than routine coagulation tests (P = 0.018). Comparing with lung cancer patients and healthy controls, LCIS patients have a significantly higher maximum amplitude (MA), fibrinogen, and D-dimer. Multivariate analysis showed that D-dimer and MA were significantly associated with ischemic stroke in lung cancer patients. ROC curve showed that the area under the curve of TEG (0.790 ± 0.048, 95% CI: 0.697-0.864) was significantly higher than routine coagulation tests (0.673 ± 0.059, 95% CI: 0.572-0.763) (P = 0.04) in identifying hypercoagulability in LCIS patients. Therefore, TEG could identify hypercoagulability in LCIS patients and healthy controls. Identification of hypercoagulability in lung cancer patients by TEG may be helpful to prevent the occurrence of LCIS.

Application of Thromboelastography to Predict Lung Cancer Stage

Objective:

Lung cancer is often associated with hypercoagulability. Thromboelastography provides integrated information on clot formation in whole blood. This study explored the possible relationship between thromboelastography and lung cancer.

Methods:

Lung cancer was staged according to the Tumor, Node, and Metastasis (TNM) classification system. Thromboelastography parameters in different stages of disease were compared. The value of thromboelastography for stage prediction was determined by area under the receiver operating characteristic curve analysis.

Results:

A total of 182 patients diagnosed with lung cancer were included. Thromboelastography parameters, including kinetics time, α-angle, and maximum amplitude, differed significantly between patients with metastatic and limited lung cancers (P < 0.05). Kinetics time was significantly reduced and maximum amplitude was significantly increased in patients with stage I and II compared with stage III and IV tumors (P < 0.05). TNM stage was significantly negatively correlated with kinetics time (r = −0.186), and significantly positively correlated with α-angle (r = 0.151) and maximum amplitude (r = 0.251) (both P < 0.05). The area under the curve for kinetics time in patients with stage I cancer was 0.637 (P < 0.05) and that for α-angle in stage ≥ II was 0.623 (P < 0.05). The areas under the curves for maximum amplitude in stage ≥ III and stage IV cancer were 0.650 and 0.605, respectively (both P < 0.05). Thromboelastography parameters were more closely associated with TNM stage in patients with lung adenocarcinoma than in the whole lung cancer population.

Conclusion:

This study identified the diagnostic value of thromboelastography parameters for determining tumor stage in patients with lung cancer. Thromboelastography can be used as an independent predictive parameter for lung cancer severity.

Routine Venous Thromboembolism Prophylaxis May Be Inadequate in the Hypercoagulable State of Severe Coronavirus Disease 2019

OBJECTIVES

The aim of this study was to determine the frequency of venous thromboembolism in critically ill coronavirus disease 2019 patients and associate a degree of inflammatory marker elevation to venous thromboembolism development.

DESIGN

An observational study that identified patients with severe coronavirus disease 2019 between March 12, 2020, and March 31, 2020. Data reported are those available through May 6, 2020.

SETTING

A multicenter study including three Indianapolis area academic hospitals.

PATIENTS

Two-hundred forty consecutive patients with confirmed severe acute respiratory syndrome coronavirus 2 infection were admitted to one of three hospitals. One-hundred nine critically ill coronavirus disease 2019 patients admitted to the ICU were included in the analysis.

INTERVENTIONS

All patients received routine subcutaneous chemical venous thromboembolism prophylaxis.

MEASUREMENTS AND MAIN RESULTS

The primary outcome of this study was to determine the frequency of venous thromboembolism and the degree of inflammatory and coagulation marker elevation associated with venous thromboembolism development. Descriptive statistics outlined the frequency of venous thromboembolism at any time during severe coronavirus disease 2019. Clinical course and laboratory metrics were compared between patients that developed venous thromboembolism and patients that did not develop venous thromboembolism. Hypercoagulable thromboelastography was defined as two or more hypercoagulable parameters.

MAIN RESULTS

One-hundred nine patients developed severe coronavirus disease 2019 requiring ICU care. The mean (± SD) age was 61 ± 16 years and 57% were male. Seventy-five patients (69%) were discharged home, 7 patients (6%) remain in the hospital, and 27 patients (25%) died. Venous thromboembolism was diagnosed in 31 patients (28%) 8 ± 7 days after hospital admission, including two patients diagnosed with venous thromboembolism at presentation to the hospital. Elevated admission D-dimer and peak D-dimer were associated with venous thromboembolism development (p < 0.05). D-dimer greater than 2,600 ng/mL predicted venous thromboembolism with an area under the receiver operating characteristic curve of 0.760 (95% CI, 0.661-0.858; p < 0.0001), sensitivity of 89.7%, and specificity of 59.5%. Twelve patients (11%) had thromboelastography performed and 58% of these patients had a hypercoagulable study. The calculated coagulation index was hypercoagulable in 50% of patients with thromboelastography.

CONCLUSIONS

These data show that coronavirus disease 2019 results in a hypercoagulable state. Routine chemical venous thromboembolism prophylaxis may be inadequate in preventing venous thromboembolism in severe coronavirus disease 2019.

Hyperthermic intraperitoneal chemotherapy enhances blood coagulation perioperatively evaluated by thromboelastography: a pilot study

Background and Objectives: Postoperative thromboembolism is a significant cause of prolonged recovery in patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Thromboelastography (TEG) can detect hypercoagulable states and predict thromboembolic complications after surgery. This study assessed the impact of CRS and HIPEC on TEG values.Methods: TEG parameters reaction time (R), kinetics time (K), angle (α), maximum amplitude (MA), and lysis percent at 60 min (LY60) were determined preoperatively, and at the end of CRS, during HIPEC, and at the end of the operation using blood samples from 15 HIPEC patients. Platelets, P-TT, and aPTT were also determined before and after CRS.Results: A total of 75 samples were analyzed. During CRS, there was a significant reduction in the mean MA (3.06 mm, p = 0.001). The mean P-TT declined by 32% (p < 0.001) and mean platelets by 55 × 10⁹/L (p < 0.001). During HIPEC, the mean R and K shortened by 1.04 min (p = 0.015) and 0.18 min (p = 0.018), respectively, whereas α increased by 2.48° (p = 0.005).Conclusions: During CRS, both TEG and conventional laboratory tests indicated hypocoagulation. During HIPEC, however, the initiation of coagulation and the kinetics of thrombin formation were accelerated.

Assessment of preoperative hypercoagulability in patients with pancreatic ductal adenocarcinoma (PDAC) using rapid thromboelastography (r-TEG)

Patients with malignant tumors are usually accompanied with hypercoagulability state and high incidence risk of venous thromboembolism (VTE), especially in patients with pancreatic ductal adenocarcinoma (PDAC). However, conventional coagulation test is failed to identify this abnormity. We retrospectively reviewed clinical data of 78 PDAC patients and 79 age-matched controls with rapid thromboelastography (r-TEG) and conventional coagulation test. The main index of r-TEG include TEG-ACT (second), R (second), K (second), angleα (°) and MA (mm), and a short TEG-ACT, short R, a short K, a broad angleα and a prolonged MA can identify hypercoagulability. Compared with age-matched controls, the PADC patients were analyzed to have a shorter K value (72. + 24 ± 22.90 vs. 85.63 ± 32.81, P = 0.0014), increased angleα value (76.20 ± 3.68 vs. 74.415 ± 4.73, P = 0.009) and MA value (63.33 ± 7.19 vs. 60.89 ± 5.52, P = 0.18). Both TEG-ACT (101.72 ± 7.57 vs. 103.78 ± 7.33, P = 0.086) and R (32.95 ± 4.72 vs. 34.34 ± 4.61, P = 0.085) value showed no significant difference in two groups. The laboratory values for conventional coagulation test were within normal ranges: PT (11.65 ± 0.95 vs. 11.38 ± 0.79, P = 0.049), INR (1.01 ± 0.09 vs. 0.98 ± 0.08, P = 0.101), aPTT (28.75 ± 3.45 vs. 28.00 ± 2.98, P = 0.149) and TT (19.44 ± 1.12 vs. 19.69 ± 1.35, P = 0.212). Incidence rates of VTE were 3.8% (3 of 78 patients) and 1.3% (1 of 79 patients) respectively (Fisher's exact test: P = 0.367). Several r-TEG indexes can indicate coagulation disorders within PDAC patients, but the incidence rates of VTE for both PDAC patients and normal controls had no significant difference. Compare to the control group, the potential hypercoagulability of PDAC patients did not correlate to thrombotic complications.

The current status of viscoelastic testing in septic coagulopathy

Sepsis can be associated with different degrees of coagulopathy, ranging from a mild activation of the coagulation system to disseminated intravascular coagulation (DIC). The evaluation of haemostasis in the context of sepsis is important since it has been shown that anticoagulant therapies were beneficial mainly in patients with sepsis-induced DIC, but not in the general population of septic patients. Sepsis-induced haemostatic disturbances are not adequately reflected by standard coagulation tests (SCTs) which only consider the plasmatic components of the haemostatic system and not the cellular components. In addition, SCTs only assess the initiation phase of coagulation and reflect the activity of pro-coagulant factors, but lack sensitivity for the anticoagulant drive and the fibrinolytic activity. Viscoelastic tests (VET) are whole-blood tests which can assess clot formation and dissociation, and the contribution of both plasmatic and cellular components with a shorter turnaround time compared to SCTs. The use of VET in septic patients has proved useful for the assessment of the fibrinolytic activity, detecting hypercoagulable status and for the diagnosis of DIC and mortality risk prediction. While having relevant advantages over SCTs, the VET also present some blind spots or limitations leaving space for future improvement by the development of new reagents or new viscoelastic parameters.

Associations between Peripheral Thromboembolic Vascular Disease and Androgen Deprivation Therapy in Asian Prostate Cancer Patients

This study aimed to investigate the risks of thromboembolic vascular disease following androgen deprivation therapy (ADT) administered to prostate cancer (PCa) patients. A total of 24,464 men with newly diagnosed PCa during 2000–2008 were recruited through a longitudinal health insurance database in Taiwan. All PCa patients were stratified into two: ADT and non-ADT groups. Patients with ADT treatment were grouped into three: surgical castration, chemical castration, and anti-androgen alone. The risks of pulmonary embolism (PE), peripheral arterial occlusion disease (PAOD), and deep vein thrombosis (DVT) were assessed in multiple Cox proportional-hazards regression with time-dependent covariates. During the 12-year follow-up period, incidence rates per 1000 person-years in ADT and non-ADT groups were 2.87 and 1.62 for DVT, 1.00 and 0.52 for PE, and 1.03 and 0.70 for PAOD, respectively. The DVT and PE risks were significantly increased in patients receiving combined androgen blockade (CAB) compared with the counterpart ADT non-recipients. After adjusting for potential risk factors, PCa patients receiving CAB had the highest PE risk (HR = 3.11), followed by DVT risk (HR = 2.53). The DVT risk remained elevated throughout the entire duration of chemical castration. However, high PE risk was observed in patients with ≤720-day treatment duration. No association was found between ADT and PAOD risks. Overall, the risks of PE and DVT were considerably heightened in Asian men subjected to CAB for PCa, whereas PAOD risk was unrelated to such treatments.

The Predictive Value of Thromboelastogram in the Evaluation of Patients with Suspected Acute Venous Thromboembolism

INTRODUCTION

The objective of this prospective study was to examine whether thromboelastogram (TEG) can predict the presence of venous thromboembolism (VTE) in patients who arrive at the emergency room with signs/symptoms that raise the suspicion of acute VTE.

METHODS

Every patient was tested for D-dimer and all TEG parameters, including: reaction time, clot time formation, alpha-angle, maximal amplitude, clot viscoelasticity, coagulation index, and clot lysis at 30 min. For categorical variables, χ2 or the Fisher exact test were used, and for continuous variables the t test or other non-parametric tests were used.

RESULTS

During 2016, a total of 109 patients were enrolled with a median age of 55.7 (21-89) years. Eighteen patients were diagnosed with VTE. Analyzing the different TEG parameters, both as continuous and categorical variables, did not reveal a statistically significant difference between VTE-positive and VTE-negative patients. Combining different TEG parameters or dividing the cohort according to gender, clinical suspicion of VTE (Well's criteria), or different levels of D-dimer did not change the results of the analysis.

CONCLUSION

The current study could not demonstrate a significant value of any TEG parameter as a predictor of VTE among patients who came to the emergency room with signs/symptoms that raise the suspicion of VTE.

Assessment of hypercoagulability using thromboelastography predicts advanced status in renal cell carcinoma

Background

Thromboelastography (TEG) has been established as a sensitive method to assess the whole coagulation process. The aim of the study was to evaluate the diagnosis significance of TEG on hypercoagulability in patients suffering renal mass.

Methods

A total of 478 patients were diagnosed with renal tumor by histolopathologic examination and were assigned to three groups. Group A: 79 patients with benign renal tumor; Group B: 317 patients with renal cell carcinoma (RCC, Fuhrman grades I and II); Group C: 82 patients with high‐risk RCC (Fuhrman grades III and IV). Subgroup analysis was performed in malignant renal tumor patients according to the TMN classification. The clinical data, whole blood TEG, and conventional coagulation tests were reviewed.

Results

There was no statistically significant difference between subgroups in respect to conventional coagulation tests. Hypercoagulablity was marked in Group C according to the TEG parameters. The elevated platelets and fibrinogen is linked with hypercoagulability in renal tumor. The positive correlation was between fibrinogen and MA value (r = .663, P < .05). The pathologic tumor stages were also associated with the TEG parameters.

Conclusion

Patients suffering advanced RCC are hypercoagulable which can be identified by TEG. MA value could be potential diagnosis indicators for detecting high‐grade RCC.

Use of Viscoelastography in Malignancy-Associated Coagulopathy and Thrombosis: A Review

The relationship between malignancy and coagulopathy is one that is well documented yet incompletely understood. Clinicians have attempted to quantify the hypercoagulable state produced in various malignancies using common coagulation tests such as prothrombin time, activated partial thromboplastin time, and platelet count; however, due to these tests' focus on individual aspects of coagulation during one specific time point, they have failed to provide clinicians the complete picture of malignancy-associated coagulopathy (MAC). Viscoelastic tests (VETs), such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM), are whole blood analyses that have the advantage of providing information related to the cumulative effects of plasma clotting factors, platelets, leukocytes, and red cells during all stages of the coagulation and fibrinolytic processes. VETs have gained popularity in the care of trauma patients to objectively measure trauma-induced coagulopathy (TIC), but the utility of VETs remains yet unrealized in many other medical specialties. The authors discuss the similarities and differences between TIC and MAC, and propose a mechanism for the hypercoagulable state of MAC that revolves around the thrombomodulin-thrombin complex as it switches between activating the protein C anticoagulation pathway or the thrombin activatable fibrinolysis inhibitor coagulation pathway. Additionally, they review the current literature on the use of TEG and ROTEM in patients with various malignancies. Although limited research is currently available, early results demonstrate the utility of both TEG and ROTEM in the prediction of hypercoagulable states and thromboembolic complications in oncologic patients.

Prospective assessment of fibrinolysis in morbid obesity: tissue plasminogen activator resistance improves after bariatric surgery

BACKGROUND

Morbid obesity is associated with an increased risk of thrombotic events, which has been attributed to increased thrombotic activity. Multiple mechanisms have been proposed to explain this increased risk, including an inflammatory state with upregulation of procoagulant and antifibrinolytic proteins. We therefore hypothesize that patients with morbid obesity are hypercoagulable and will revert to normal after bariatric surgery.

OBJECTIVES

To evaluate changes in the hypercoagulable state after bariatric surgery.

SETTING

University Hospital, Bariatric Center of Excellence, United States.

METHODS

Thromboelastography (TEG) data were collected on 72 subjects with morbid obesity, with 36 who had 6 months of follow-up after bariatric surgery. TEG data of 75 healthy subjects (HS) without obesity, recent trauma or surgery, acute infection, or chronic conditions (e.g., liver, cardiovascular, or kidney disease; cancer; diabetes; autoimmune or inflammatory disorders; and disorders of coagulation) were used for comparison. TEG was performed alone and with the addition of 75 and 150 ng/mL tissue plasminogen activator (tPA) to quantify fibrinolysis resistance (tPA-challenged TEG).

RESULTS

The bariatric surgery cohort had a median age of 40.5 years, a median body mass index of 44.6 kg/m², and 90% female patients. Median body mass index reduced significantly 6 months post surgery but remained elevated compared with the HS group (31.4 versus 25.4 kg/m², P < .0001). At 6 months post surgery, subjects had longer reaction time (mean difference, 1.3; P = .02), lower maximum amplitude (-2.4, P = .01), and increased fibrinolysis with low-dose (3.1, P < .0001) and high-dose tPA-challenged TEG (9, P < .0001). Compared with HS, the postsurgery TEG values were still more likely to be abnormal (all P < .05).

CONCLUSIONS

Patients with morbid obesity form stronger clots more rapidly and are more resistant to fibrinolysis than subjects without obesity. Bariatric surgery significantly improved the hypercoagulable profile and fibrinolysis resistance of morbid obesity.

Tranexamic acid is beneficial for reducing perioperative blood loss in transurethral resection of the prostate

The aim of this randomized controlled trial was to evaluate the effect of tranexamic acid (TXA) on postoperative blood loss during transurethral resection of the prostate (TURP) for benign prostatic hyperplasia (BPH). A total of 60 patients with BPH and undergoing TURP were randomized into TXA and control groups. Patients were intravenously administered 1 g TXA or placebo (0.9% sodium chloride solution), respectively, after the induction of anesthesia for TURP. Intraoperative and postoperative bladder irrigation volumes and blood loss volumes were compared between the two groups. Coagulation function (measured by prothrombin, activated partial thromboplastin and thrombin time and fibrinogen levels) was measured before the operation and at 4 h post-operation. Complications from thromboembolic events, such as lower-limb and pulmonary embolisms, were also noted. The TXA group had significantly decreased blood loss intraoperatively and at 4 h postoperatively compared with the control group (P<0.05). The 24 h postoperative blood loss and coagulation function of the two groups were not significantly different. No thromboembolic events or other complications occurred in either group. In conclusion, a preoperative single dose of TXA was indicated to reduce perioperative blood loss in TURP without a notable increase in thrombosis risk.

Microfluidics contrasted to thrombelastography: perplexities in defining hypercoagulability

BACKGROUND

Elevated clot strength (maximum amplitude [MA]) measured by thrombelastography (TEG) is associated with thrombotic complications. However, it remains unclear how MA translates to thrombotic risks, as this measurement is independent of time, blood flow, and clot degradation. We hypothesize that under flow conditions, increased clot strength correlates to time-dependent measurements of coagulation and resistance to fibrinolysis.

MATERIALS AND METHODS

Surgical patients at high risk of thrombotic complications were analyzed with TEG and total thrombus-formation analysis system (T-TAS). TEG hypercoagulability was defined as an r <10.2 min, angle >59, MA >66 or LY30 <0.2% (based off of healthy control data, n = 141). The T-TAS AR and PL chips were used to measure clotting at arterial shear rates. T-TAS measurements include occlusion start time, occlusion time (OT), occlusion speed (OSp), and total clot generation (area under the curve). These measurements were correlated to TEG indices (R time, angle, MA, and LY30). Both T-TAS and TEG assays were challenged with tissue plasminogen activator (t-PA) to assess clot resistance to fibrinolysis.

RESULTS

Thirty subjects were analyzed, including five controls. TEG-defined hypercoagulability by MA was detected in 52% of the inflammatory bowel disease/cancer patients; 0% was detected in the controls. There were no TEG measurements that significantly correlated with T-TAS AR and PL chip. However, in the presence of t-PA, T-TAS AR determined OSp to have an inverse relationship with TEG angle (-0.477, P = 0.012) and LY30 (-0.449, P = 0.019), and a positive correlation with R time (0.441 P = 0.021). In hypercoagulability determined by TEG MA, T-TAS PL had a significantly reduced OT (4:07 versus 6:27 min, P = 0.043). In hypercoagulability defined by TEG LY30, T-TAS PL had discordant findings, with a significantly prolonged OT (6:36 versus 4:30 min, P = 0.044) and a slower OSp (10.5 versus 19.0 kPa/min, P = 0.030).

CONCLUSIONS

Microfluidic coagulation assessment with T-TAS has an overall poor correlation with most TEG measurements in a predominantly hypercoagulable patient population, except in the presence of t-PA. The one anticipated finding was an elevated MA having a shorter time to platelet-mediated microfluidic occlusion, supporting the role of platelets and hypercoagulability. However, hypercoagulability defined by LY30 had opposing results in which a low LY30 was associated with a longer PL time to occlusion and slower OSp. These discordant findings warrant ongoing investigation into the relationship between clot strength and fibrinolysis under different flow conditions.

Thromboelastography-derived parameters for the prediction of acute thromboembolism following non-steroidal anti-inflammatory drug-induced gastrointestinal bleeding: A retrospective study

Efficacy of thromboelastography (TEG)-derived parameters for the prediction of acute thromboembolism (AT) in patients with non-steroidal anti-inflammatory drug (NSAID)-induced gastrointestinal bleeding (GIB) remains to be determined. A retrospective propensity score matching (PSM) study was performed to evaluate this efficacy. Patients with NSAID-induced GIB (98 with AT; 830 without AT) were matched for age, sex and history of cardiovascular and cerebrovascular diseases using PSM. Multivariate logistic regression was used to determine the efficacy of TEG-derived predictors of AT. Mean Decrease Gini (MDG) coefficients were used to rank the importance of the variables from random forest algorithm results. Univariate analysis indicated that the following indexes were significantly different between the two groups: Reaction time (R value), coagulation forming time, solidification angle, maximum amplitude (MA), coagulation index (CI), hemoglobin levels, D-dimer levels, platelet aggregation test (pAgt) results, fibrinogen levels and Acute Physiology and Chronic Health Evaluation II score (all P<0.001). Multifactor logistic regression analysis indicated that the R value (P=0.010), solidification angle (P=0.004), MA (P=0.038), D-dimer levels (P=0.012) and pAgt results (P=0.015) were independent predictors of AT in patients with NSAID-induced GIB, achieving an area under the curve of 0.999 in receiver operating characteristic curve analyses. The five most important parameters according to the MDG scores (MDGS) were: Solidification angle (MDGS=58.14), R value (MDGS=20.42), pAgt results (MDGS=15.61), D-dimer levels (MDGS=12.78) and CI (MDGS=12.61). The results of the present study indicated that TEG-derived parameters including the R value, solidification angle, MA and CI, as well as D-dimer levels and pAgt score were significant predictors of AT in patients with NSAID-induced GIB.

The role of extended venous thromboembolism prophylaxis following urologic pelvic surgery

With the emergence of evidence that venous thromboembolisms (VTE) typically occurs following discharge after urologic pelvic surgery, the focus on extended VTE prophylaxis has intensified. Urologists should have a comprehensive understanding of various VTE risk factors in order to weigh the risk of postoperative hemorrhage with the possibility of fatal pulmonary embolus. Risk factors such as advanced age, obesity, and active malignancy are especially common in patient's undergoing urologic pelvic surgery, and thus this issue becomes particularly relevant to the practicing urologist. In previous years, guidelines on extended VTE prophylaxis have either been vague or not urology specific; however, the European Association of Urology has recently issued recommendations on VTE prophylaxis stratified by VTE risk and surgery type. Although these guidelines are a major advance, definitive answers on this question may prove elusive in the form of prospective randomized data given the low incidence of clinically significant postoperative VTE.

Comparison Between Thromboelastography and Conventional Coagulation Tests in Surgical Patients With Localized Prostate Cancer

We aimed to examine hypercoagulable and hypocoagulable conditions in patients with prostate cancer using thromboelastography (TEG) and correlate TEG parameters with conventional coagulation test. The t test was used for comparing TEG parameters and routine coagulation results. Spearman rank-order correlation was used to describe the relationship of TEG and conventional tests. Sensitivity, specificity, positive predictive values, and negative predictive values were determined for bleeding and thrombosis. Totally, 20 patients had active bleeding postoperatively, 16 of whom showed hypocoagulation on TEG test and 9 of whom showed hypocoagulation by routine coagulation test ( P = .024). Overall, 60 patients did not have active bleeding postoperatively, 51 of whom showed hypercoagulation detected by TEG test and 42 of whom showed hypercoagulation found by routine coagulation test ( P = .040). Remarkably, patients had a little higher fibrinogen (FIB) compared to controls. There was no statistical difference in any of the conventional coagulation indexes between the groups. Correlation analysis showed that reaction time (R) and coagulation time (K) were positively correlated with the prothrombin time-international normalized ratio (PT-INR) and negatively correlated with FIB ( P < .001). Contrarily, α-angle and maximum amplitude (MA) were negatively correlated with PT-INR but positively correlated with FIB. Significantly, MA showed the strongest correlation with FIB and R exhibited the strongest correlation with PT-INR. Sensitivity and specificity for bleeding and thrombosis in TEG were higher than those in conventional coagulation test. Accordingly, TEG might be superior in evaluating hypercoagulation and detecting the risk of bleeding in patients with prostate cancer.

Thromboelastometry: Relation to the severity of liver cirrhosis in patients considered for liver transplantation

The severity of liver disease is assessed by scoring systems, which include the conventional coagulation test prothrombin time-the international normalized ratio (PT-INR). However, PT-INR is not predictive of bleeding in liver disease and thromboelastometry (ROTEM) has been suggested to give a better overview of the coagulation system in these patients. It has now been suggested that coagulation as reflected by tromboelastomety may also be used for prognostic purposes. The objective of our study was to investigate whether thrombelastometry may discriminate the degree of liver insufficiency according to the scoring systems Child Pugh and Model for End-stage Liver Disease (MELD).Forty patients with chronic liver disease of different etiologies and stages were included in this observational cross-sectional study. The severity of liver disease was evaluated using the Child-Pugh score and the MELD score, and blood samples for biochemistry, conventional coagulation tests, and ROTEM were collected at the time of the final assessment for liver transplantation. Statistical comparisons for the studied parameters with scores of severity were made using Spearman correlation test and receiver-operating characteristic (ROC) curves.Spearman correlation coefficients indicated that the thromboelastometric parameters did not correlate with Child-Pugh or MELD scores. The ROC curves of the thromboelastometric parameters could not differentiate advanced stages from early stages of liver cirrhosis.Standard ROTEM cannot discriminate the stage of chronic liver disease in patients with severe chronic liver disease.

Effects of androgen-deprivation therapy on hypercoagulability in prostate cancer patients: A prospective, longitudinal study

INTRODUCTION

Androgen-deprivation therapy (ADT) is the mainstay of systemic therapy for advanced prostate cancer (PCa), but has significant adverse effects, including increasing concern for cardiovascular (CV) and thromboembolic (TE) complications. This study carefully investigates any relationship between ADT use and hypercoagulability as a possible mechanism of these adverse effects.

METHODS

We performed a prospective, longitudinal study in a cohort of patients with advanced PCa initiating ADT (n=18). Controls included men with biochemical failure after local therapy on watchful waiting (n=10), as well as healthy controls (n=8). Global hemostasis was evaluated using the sensitive global hemostasis assay, thromboelastography (TEG). Patients were evaluated at baseline and every three months for a minimum of 12 months.

RESULTS

The results of the TEG studies demonstrated 14/18 (78%) of advanced PCa patients had evidence of a hypercoagulable state before initiating therapy. Significant baseline hypercoagulability was documented in this cohort compared to the two control groups. ADT did not appear to exacerbate hypercoagulability over time as a whole: only 10/18 (56%) patients had TEG findings consistent with hypercoagulability at the end of study. However, 3/18 (17%) PCa patients initiating ADT had significantly new hypercoagulable TEG changes on treatment compared to baseline.

CONCLUSIONS

This prospective pilot study demonstrates a complex interaction between ADT and hypercoagulable state in men with advanced PCa. TEG abnormalities were mostly associated with volume of cancer as compared to ADT use; however, it is possible that ADT may lead to hypercoagulability in a subset of men, suggesting that sensitive monitoring of coagulation of men on ADT could help identify those at risk of developing CV/TE complications. Study limitations include the relatively small cohort of men followed after initiating ADT and these results require confirmation in a larger trial to rule out subtle effects on hypercoagulability.

Thromboelastography (TEG)

Thromboelastography (TEG) has been used for decades to guide transfusion therapy during cardiac and hepatic surgeries. Renewed interest and improved technology have led to wider applications of TEG in other areas of hemostasis. To correctly interpret the data generated and to validate outcomes, it is important to improve the understanding of the differences in the currently available assay procedures, the issues related to sample activation, and the importance of the use of appropriate controls. Current TEG assays use a variety of samples and can vary slightly in the procedures. In this chapter, we very briefly review TEG applications and discuss interpretations, normal ranges, and reference controls, and we explain the method of TEG run using standard citrated native blood samples. We provide detailed technical steps and tips. We discuss precautions and issues related to the assay, which we hope can guide toward better application and data interpretation.

Fractal dimension (df) as a new structural biomarker of clot microstructure in different stages of lung cancer

Venous thromboembolism (VTE) is common in cancer patients, and is the second commonest cause of death associated with the disease. Patients with chronic inflammation, such as cancer, have been shown to have pathological clot structures with modulated mechanical properties. Fractal dimension (df) is a new technique which has been shown to act as a marker of the microstructure and mechanical properties of blood clots, and can be performed more readily than current methods such as scanning electron microscopy (SEM). We measured df in 87 consecutive patients with newly diagnosed lung cancer prior to treatment and 47 matched-controls. Mean group values were compared for all patients with lung cancer vs controls and for limited disease vs extensive disease. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images. Significantly higher values of df were observed in lung cancer patients compared with controls and patients with extensive disease had higher values than those with limited disease (p< 0.05), whilst conventional markers failed to distinguish between these groups. The relationship between df of the incipient clot and mature clot microstructure was confirmed by SEM and computational modelling: higher df was associated with highly dense clots formed of smaller fibrin fibres in lung cancer patients compared to controls. This study demonstrates that df is a sensitive technique which quantifies the structure and mechanical properties of blood clots in patients with lung cancer. Our data suggests that df has the potential to identify patients with an abnormal clot microstructure and greatest VTE risk.