Thromboelastography (TEG)

The impact of different treatments on thromboelastography and other conventional parameters in patients with colorectal cancer

OBJECTIVE

To comprehend the effects of diverse therapeutic interventions on thromboelastography (TEG) and conventional coagulation parameters among individuals diagnosed with colorectal cancer, this study aims to explore the clinical relevance of both thromboelastography and conventional coagulation metrics in evaluating coagulation function and predicting the incidence of thrombotic and hemorrhagic events in patients with colorectal cancer.

METHODS

A cohort of 122 patients with colorectal cancer retrospectively recruited and divided into 2 groups: those undergoing surgical intervention (operation group) and those not subjected to surgery (non-operation group). According to the different types of treatment they received, the operation group was divided into chemotherapy-only group and a group receiving a combination of targeted therapy and chemotherapy. Blood samples were collected on admission and subjected to coagulation parameter assessment, including conventional coagulation tests and thromboelastography (TEG) assessment. Receiver operating characteristic (ROC) analysis was performed to predict the occurrence of complications in patients with colorectal cancer.

RESULTS

Compared with the operation group, the non-operation group showed significant reductions in reaction time(R-time) and kinetics time (K-time), and significant elevation in angle, maximum amplitude (MA), fibrinogen and platelets. Patients receiving targeted therapy and chemotherapy had lower angle and maximum amplitude and higher R-time and K-time, activated partial thromboplastin time and fibrinogen. The area under the curve for TEG in patients without treatment was 0.802. The area under the curve for TEG and conventional coagulation parameters were 0.654 and 0.660 respectively.

CONCLUSION

Diverse treatments distinctly impact on the coagulation indicators of individuals diagnosed with colorectal cancer. The coagulation parameters observed in patients prior to operation suggest a hypercoagulable state. Nevertheless, following postoperative chemotherapy and targeted therapy, this hypercoagulable state demonstrates a notable improvement, occasionally leading to a propensity for hypocoagulation. The findings of this investigation underscore the unique clinical importance of thromboelastography (TEG) alongside traditional coagulation parameters, demonstrating that these diagnostic tools possess complementary value and cannot be substituted interchangeably.

Thromboelastography in Long-Term Antiplatelet Therapy for Patients Diagnosed with Benign Prostate Hyperplasia Undergoing Holmium Laser Enucleation of the Prostate: A Retrospective Study

Objective

To compare low- vs high-power HoLEP effects on coagulation in patients on antiplatelet (AP) therapy via thromboelastography (TEG).

Methods

210 patients was retrospectively analyzed and stratificated into three discrete groups, specifically: Group A (AP therapy, high-power HoLEP, n = 72); Group B (AP therapy, low-power HoLEP, n=73); Group C (no AP therapy, low-power HoLEP, n = 65). Baseline characteristics and coagulation profiles via TEG were compared. Univariate and multivariate analyses were conducted to identify independent risk factors associated with hematuria. Furthermore, parameters such as IPSS, Qmax, post-void residual volume V2 and PSA levels were recorded during 1year follow-up.

Results

No differences in terms of baseline characteristics across all groups. Significant differences were observed in the duration of enucleation, morcellation, bladder irrigation, post-operative catheterization, length of hospital stay and the extent of hemoglobin reduction (F = 54.06, 8.54, 6.68, 9.24, 17.06, 5.97, p < 0.05). No differences were noted in postoperative hematuria, urine retention, transfusion rates, and SUI (x1 2 = 1.082 ; x2 2 = 0.197,; x3 2 = 3.981;x4 2 = 0.816, p > 0.05). Univariate and multivariate analyses revealed that prostate volume emerged as an independent risk factor for hematuria (OR 1.080, 95% CI: 1.007-1.158, p = 0.031). Clinical outcomes including Qmax, IPSS, V2, and PSA demonstrated significant enhancement during 1 year follow-up.

Conclusion

Compared to HP-HoLEP, LP-HoLEP effectively reduces surgical and subsequent processing times, decreases hospital stay duration, and diminishes hemoglobin decline, offering a viable option without discontinuing AP therapy.

Clinical value of thromboelastography in predicting the risk of recurrence of acute ischemic stroke

Background

Thromboelastography (TEG) can objectively reflect the formation, development and rupture process of thrombosis in patients, but there are limited data on whether TEG can be used as a predictive tool for recurrence in patients with acute ischemic stroke.

Objective

To explore the TEG risk of recurrence in patients with acute ischemic stroke predictive value.

Methods

A total of 441 patients with acute ischemic stroke who met the research criteria in the First Affiliated Hospital of Henan University of Traditional Chinese Medicine from January 2020 to December 2021 were selected as the research objects. TEG was measured in all patients, and the main parameters of TEG (R value, indicating coagulation reaction time; K value and Angle, the rate of blood clot formation; MA value, indicating the maximum amplitude). The primary outcome of this study was ischemic stroke recurrence. Recurrent events included cerebral infarction, cerebral hemorrhage, TIA, and were determined by combining imaging events and clinical events. Logistic regression analysis was used to explore the influencing factors of recurrence in patients with acute ischemic stroke.

Results

Fifty-six patients (12.7%) had recurrence. Multivariate Logistic regression analysis showed that: Age [OR = 1.078, 95%CI(1.024, 1.135)], triglyceride [OR = 1.541, 95%CI(1.033, 2.298)], glycosylated hemoglobin [OR = 1.401, 95%CI(1.097, 1.790)], history of hypertension [OR = 16.046, p < 0.05], 95%CI(4.726, 54.489), R value [OR = 0.533, 95%CI(0.351, 0.809)], MA value [OR = 1.399, 95%CI(1.004, 1.949)] were independent influencing factors for hemorrhagic transformation in patients with acute ischemic stroke.

Conclusion

TEG has some value in predicting recurrence in patients with acute ischemic stroke, and the MA value in TEG [AUC = 0.806 (95%CI:0.747-0.867), with a sensitivity of 78.6% and a specificity of 70.4%], predicted the most significant efficiency of AIS recurrence.

Classic Light Transmission Platelet Aggregometry: Do We Still Need it?

For more than 50 years, light transmission aggregometry has been accepted as the gold standard test for diagnosing inherited platelet disorders in platelet-rich plasma, although there are other functional approaches performed in whole blood. In this article, several advantages and disadvantages of this technique over other laboratory approaches are discussed in the view of recent guidelines, and the necessity of functional assays, such as light transmission aggregometry in the era of molecular genetic testing, is highlighted.

Comparative studies between humans and golden Syrian hamsters via thromboelastography

BACKGROUND

Thromboelastography (TEG) is a widely utilized clinical testing method for real-time monitoring of platelet function and the thrombosis process. Lipid metabolism disorders are crucial risk factors for thrombosis. The lipid metabolism characteristics of hamsters resemble those of humans more closely than mice and rats, and their relatively large blood volume makes them suitable for studying the mechanisms of thrombosis related to plasma lipid mechanisms. Whole blood samples from golden Syrian hamsters and healthy humans were obtained following standard clinical procedures. TEG was employed to evaluate coagulation factor function, fibrinogen (Fib) function, platelet function, and the fibrinolytic system.

METHODS

The whole blood from hamster or healthy human was isolated following the clinical procedure, and TEG was employed to evaluate the coagulation factor function, Fib function, platelet function, and fibrinolytic system. Coagulation analysis used ACLTOP750 automatic coagulation analysis pipeline. Blood routine testing used XN-2000 automatic blood analyzer.

RESULTS

TEG parameters revealed that hamsters exhibited stronger coagulation factor function than humans (reaction time [R], p = 0.0117), with stronger Fib function (alpha angle, p < 0.0001; K-time [K], p < 0.0001). Platelet function did not differ significantly (maximum amplitude [MA], p = 0.077). Hamsters displayed higher coagulation status than humans (coagulation index [CI], p = 0.0023), and the rate of blood clot dissolution in hamsters differed from that in humans (percentage lysis 30 min after MA, p = 0.02). Coagulation analysis parameters indicated that prothrombin time (PT) and activated partial thromboplastin time (APTT) were faster in hamsters than in humans (PT, p = 0.0014; APTT, p = 0.03), whereas the Fib content was significantly lower in hamsters than in humans (p < 0.0001). No significant difference was observed in thrombin time (p = 0.1949).

CONCLUSIONS

In summary, TEG could be used to evaluate thrombosis and bleeding parameters in whole blood samples from hamsters. The platelet function of hamsters closely resembled that of humans, whereas their coagulation function was significantly stronger.

Temperature effect on coagulation function in mild hypothermic patients undergoing thoracic surgeries: thromboelastography (TEG) versus standard tests

PURPOSE

Our previous research has revealed that mild hypothermia leads to excessive bleeding in thoracic surgeries, while the underlying mechanism stayed unrevealed by the standard coagulation tests. The research question in this study was as follows: "How does mild hypothermia impair the hemostatic function in patients receiving thoracic surgeries?". The purpose was to detect the disturbed coagulation processes by comparing the TEG parameters in patients receiving active vs. passive warming during thoracic surgeries.

METHODS

Standard coagulation tests and thromboelastography (TEG) were adopted to compare the hemostatic functions in patients receiving active vs. passive warming during thoracic surgeries. Furthermore, blood samples from passive warming group were retested for TEG at actual core body temperatures.

RESULTS

Sixty-four eligible patients were included in this study. TEG revealed that mild hypothermia significantly disturbed coagulation by decreasing MA (59.4 ± 4.5 mm vs. 64.2 ± 5.7 mm, p = 0.04) and α angle (70.4 ± 5.2° vs. 74.9 ± 4.4°, p = 0.05) and prolonging ACT (122.2 ± 19.3 s vs. 117.3 ± 15.2 s, p = 0.01) and K time (1.9 ± 1.0 s vs. 1.3 ± 0.4 min, p = 0.02). TEGs conducted under core body temperatures revealed more impaired coagulation than those incubated at 37 °C. Furthermore, postoperative shivering and waking time were significantly increased in mild hypothermic patients.

CONCLUSION

Mild hypothermia significantly impaired coagulation function in patients receiving thoracic surgeries, which could be detected by TEGs other than the standard coagulation tests. Temperature-adjusted TEGs may provide a preferable method of hemostatic monitoring and transfusion guidance in thoracic surgeries, which warrants further clinical investigations.

Clinical guidance for unfractionated heparin dosing and monitoring in critically ill patients

INTRODUCTION

Unfractionated heparin is a widely used anticoagulant in critically ill patients. It has a well-established safety profile and remains an attractive option for clinicians due to its short half-life and reversibility. Heparin has a unique pharmacokinetic profile, which contributes to significant inter-patient and intra-patient variability in effect. The variability in anticoagulant effect combined with heparin's short half-life mean close monitoring is required for clinical efficacy and preventing adverse effects. To optimize heparin use in critically ill patients, effective monitoring assays and dose adjustment strategies are needed.

AREAS COVERED

This paper explores the use of heparin as an anticoagulant and optimal approaches to monitoring in critically ill patients.

EXPERT OPINION

Conventional monitoring assays for heparin dosing have significant limitations. Emerging data appear to favor using anti-Xa assay monitoring for heparin anticoagulation, which many centers have successfully adopted as the standard. The anti-Xa assay appears have important benefits relative to the aPTT for heparin monitoring in critically ill patients, and should be considered for broader use.

Time to maximum amplitude of thromboelastography can predict mortality in patients with severe COVID-19: a retrospective observational study

Objective

To predict mortality in severe patients with COVID-19 at admission to the intensive care unit (ICU) using thromboelastography (TEG).

Methods

This retrospective, two-center, observational study involved 87 patients with PCR-and chest CT-confirmed severe COVID-19 who were admitted to at Wuhan Huoshenshan Hospital and the 908th Hospital of Chinese PLA Logistic Support Force between February 2020 and February 2023. Clinic demographics, laboratory results, and outcomes were compared between those who survived and those who died during hospitalization.

Results

Thromboelastography showed that of the 87 patients, 14 were in a hypercoagulable state, 25 were in a hypocoagulable state, and 48 were normal, based on the time to maximum amplitude (TMA). Patients who died showed significantly lower α angle, but significantly longer R-time, K-time and TMA than patients who survived. Random forest selection showed that K-time, TMA, prothrombin time (PT), international normalized ratio (INR), D-dimer, C-reactive protein (CRP), aspartate aminotransferase (AST), and total bilirubin (Tbil) were significant predictors. Multivariate logistic regression identified that TMA and CRP were independently associated with mortality. TMA had a greater predictive power than CRP levels based on time-dependent AUCs. Patients with TMA ≥ 26.4 min were at significantly higher risk of mortality (hazard ratio 3.99, 95% Confidence Interval, 1.92-8.27, p < 0.01).

Conclusion

TMA ≥26.4 min at admission to ICU may be an independent predictor of in-hospital mortality for patients with severe COVID-19.

Investigation of thrombin concentration at the time of clot formation in simultaneous thrombin and fibrin generation assays

Thrombin generation (TG) and fibrin clot formation represent the central process of blood coagulation. Up to 95% of thrombin is considered to be generated after the clot is formed. However, this was not investigated in depth. In this study, we conducted a quantitative analysis of the Thrombin at Clot Time (TCT) parameter in 5758 simultaneously recorded TG and clot formation assays using frozen plasma samples from commercial sources under various conditions of activation. These samples were supplemented with clotting factor concentrates, procoagulant lipid vesicles and a fluorogenic substrate and triggered with tissue factor (TF). We found that TCT is often close to a 10% of thrombin peak height (TPH) yet it can be larger or smaller depending on whether the sample has low or high TPH value. In general, the samples with high TPH are associated with elevated TCT. TCT appeared more sensitive to some procoagulant phenotypes than other commonly used parameters such as clotting time, TPH or Thrombin Production Rate (TPR). In a minority of cases, TCT were not predicted from TG parameters. For example, elevated TCT (above 15% of TPH) was associated with either very low or very high TPR values. We conclude that clotting and TG assays may provide complementary information about the plasma sample, and that the TCT parameter may serve as an additional marker for the procoagulant potential in plasma sample.

Features of thromboelastogram in populations exposed to or transferring from high altitude

Background

Thromboelastogram (TEG) is an effective indicator that monitors the dynamic changes of blood coagulation in real-time. It still remains controversial about the performance and influence of coagulation at high altitude. The present study intends to describe comprehensively the clinical features of TEG in populations exposed to or transferring from high altitude.

Methods

Two groups were recruited in the present study. Group A included young males who worked at high-altitude (4888 m or 5418 m) areas for some time, while Group B included young males who had recently returned from high-altitude (4888 m or 5418 m) areas. Medical examinations were performed using portable devices. Spearman's test was used to evaluate the correlations between thromboelastogram (TEG) variables and other variables. Logistic regression analysis was used to analyze the factors affecting various abnormal TEG variables.

Results

A total of 51 adult males were included in the two groups. Significantly increased reaction time (R) and decreased maximum amplitude (MA) were found in group B (P < 0.05). No significant differences were observed in the comparisons of K and angle between the two groups. Various TEG variables were identified to be correlated with different coagulation and biochemical variables. Logistic regression analysis demonstrated that abnormal R was independently associated with direct bilirubin, and abnormal K was independently associated with the platelet count in Group A (P < 0.05). However, none of the factors were independently associated with abnormal TEG variables in Group B.

Conclusion

Populations exposed to or transferring from high altitudes are characterized by different TEG characteristics. Our findings give a comprehensive description of the complex interaction between TEG indexes, coagulation dynamics, and hematological parameters, which can help guide the development of appropriate medical approaches tailored to the unique needs of these populations.

Comparison of the Correlation Between Coagulation Indices and Rivaroxaban Concentrations

BACKGROUND

Rivaroxaban has predictable pharmacokinetics and pharmacodynamics. However, monitoring rivaroxaban concentrations should be provided for special patients with hepatic insufficiency, high bleeding risk, and high thrombotic risk.

OBJECTIVE

This study aimed to correlate chromogenic anti-Xa assay, prothrombin time (PT), activated partial thromboplastin time (APTT), thromboelastogram reaction time (TEG R-time), and rivaroxaban concentration measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) (MS-Riva).

METHODS

Peripheral venous blood was collected from recruited patients 30 minutes before and 2 to 4 hours after drug administration. High-performance liquid chromatography-tandem mass spectrometry and chromogenic anti-Xa assay measured rivaroxaban concentration. Different assays were compared by Pearson correlation coefficient and Bland-Altman analysis.

RESULTS

A total of 104 patients with 191 plasma were included in the study. Overall analysis shows that chromogenic anti-Xa assay, PT, APTT, and TEG R-time strongly correlated with MS-Riva (r = 0.986; r = 0.884; r = 0.741; r = 0.739; P < 0.001). Rivaroxaban peak concentration detected by HPLC-MS/MS (MS-peak) showed a very strong correlation with the chromogenic anti-Xa assay (r = 0.977, P < 0.001) and moderate correlation with PT, APTT, and TEG R-time (r = 0.670; r = 0.571; r = 0.481, P < 0.001). Rivaroxaban trough concentration detected by HPLC-MS/MS (MS-trough) correlated strongly with the chromogenic anti-Xa assay (r = 0.884, P < 0.001), weakly with APTT (r = 0.313; P = 0.043), and not significantly with PT and TEG R-time (P = 0.140; P = 0.341).

CONCLUSION AND RELEVANCE

High-performance liquid chromatography-tandem mass spectrometry/MS is the preferred choice for monitoring peak and tough concentrations, followed by anti-Xa, while PT is only suitable for peak concentrations. This study can help the clinicians to better adjust the medication regimen and reduce the risk of recurrence of thrombosis as well as the risk of bleeding.

Hypocoagulability in Children With Decompensated Chronic Liver Disease and Sepsis: Assessment by Thromboelastography

Objective

To evaluate the coagulation status of children with decompensated chronic liver disease (DCLD) and infection and factors affecting it using thromboelastography (TEG).

Methods

Coagulation status of children admitted with DCLD and infection was assessed by international normalized ratio (INR), platelet count, and TEG [reaction time (R), kinetic time (K), α-angle (AA), maximum amplitude (MA), coagulation index (CI), and lysis index (LY30)] at admission and at 7-14 days after treatment. CI < -3 represents hypocoagulable state. Clinical profile including systemic inflammatory response syndrome (SIRS), infection severity, bleeding, treatment response, and outcome were noted.

Results

Thirty children (21 boys, median (IQR) age 78 [15.7-180] months) were studied prospectively. At admission, 29 (96.7%) had prolonged INR, 24 (80%) had thrombocytopenia, and 17 (56.6%) were hypocoagulable by TEG. Nine of 30 (30%) had normal TEG but deranged INR and platelets. Nineteen (63.3%) cases had SIRS, 11 (36.6%) had severe sepsis, and 8 (26.6%) had bleeding. Hypocoagulable state was common in severe sepsis than sepsis/infection (81.1% versus 42.1%; P = 0.05) and persistent (n = 4) versus recovered SIRS (n = 15, 100% versus 33%; P = 0.03). Bleeders had prolonged R-time (7.8 versus 5.4 min; P = 0.03), smaller MA (30.2 versus 47 mm; P = 0.05), and α-angle (40.4 versus 62.9; P = 0.03) but similar INR and platelets than nonbleeders. Six patients (20%) had poor in-hospital outcomes; R-time ≥8.5 min predicted mortality with high sensitivity (83%) and specificity (100%).

Conclusions

Fifth-seven percent of children with DCLD and infection were hypocoagulable by TEG. Severe sepsis and persistent SIRS worsened the coagulation status. TEG identifies bleeders better than INR and platelet count. R-time ≥8.5 min predicts a poor hospital outcome.

Establishment and validation of a nomogram based on coagulation parameters to predict the prognosis of pancreatic cancer

BACKGROUND

In recent years, multiple coagulation and fibrinolysis (CF) indexes have been reported to be significantly related to the progression and prognosis of some cancers.

OBJECTIVE

The purpose of this study was to comprehensively analyze the value of CF parameters in prognosis prediction of pancreatic cancer (PC).

METHODS

The preoperative coagulation related data, clinicopathological information, and survival data of patients with pancreatic tumor were collected retrospectively. Mann Whitney U test, Kaplan-Meier analysis, and Cox proportional hazards regression model were applied to analyze the differences of coagulation indexes between benign and malignant tumors, as well as the roles of these indexes in PC prognosis prediction.

RESULTS

Compared with benign tumors, the preoperative levels of some traditional coagulation and fibrinolysis (TCF) indexes (such as TT, Fibrinogen, APTT, and D-dimer) were abnormally increased or decreased in patients with pancreatic cancer, as well as Thromboelastography (TEG) parameters (such as R, K, α Angle, MA, and CI). Kaplan Meier survival analysis based on resectable PC patients showed that the overall survival (OS) of patients with elevated α angle, MA, CI, PT, D-dimer, or decreased PDW was markedly shorter than other patients; moreover, patients with lower CI or PT have longer disease-free survival. Further univariate and multivariate analysis revealed that PT, D-dimer, PDW, vascular invasion (VI), and tumor size (TS) were independent risk factors for poor prognosis of PC. According to the results of modeling group and validation group, the nomogram model based on independent risk factors could effectively predict the postoperative survival of PC patients.

CONCLUSION

Many abnormal CF parameters were remarkably correlated with PC prognosis, including α Angle, MA, CI, PT, D-dimer, and PDW. Furthermore, only PT, D-dimer, and PDW were independent prognostic indicators for poor prognosis of PC, and the prognosis prediction model based on these indicators was an effective tool to predict the postoperative survival of PC.

Nomogram for predicting disseminated intravascular coagulation in heatstroke patients: A 10 years retrospective study

Background

Disseminated intravascular coagulation (DIC) can lead to multiple organ failure and death in patients with heatstroke. This study aimed to identify independent risk factors of DIC and construct a predictive model for clinical application.

Methods

This retrospective study included 87 patients with heatstroke who were treated in the intensive care unit of our hospital from May 2012 to October 2022. Patients were divided into those with DIC (n = 23) or without DIC (n = 64). Clinical and hematological factors associated with DIC were identified using a random forest model, least absolute shrinkage and selection operator (LASSO) regression and support vector machine-recursive feature elimination (SVM-RFE). Overlapping factors were used to develop a nomogram model, which was diagnostically validated. Survival at 30 days after admission was compared between patients with or without DIC using Kaplan-Meier analysis.

Results

Random forest, LASSO, and SVM-RFE identified a low maximum amplitude, decreased albumin level, high creatinine level, increased total bilirubin, and aspartate transaminase (AST) level as risk factors for DIC. Principal component analysis confirmed that these independent variables differentiated between patients who experienced DIC or not, so they were used to construct a nomogram. The nomogram showed good predictive power, with an area under the receiver operating characteristic curve of 0.976 (95% CI 0.948–1.000) and 0.971 (95% CI, 0.914–0.989) in the internal validation. Decision curve analysis indicated clinical utility for the nomogram. DIC was associated with significantly lower 30 days survival for heatstroke patients.

Conclusion

A nomogram incorporating coagulation-related risk factors can predict DIC in patients with heatstroke and may be useful in clinical decision-making.

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.

Laboratory Testing of Hemostasis in Pregnancy: A Brief Overview

Normal pregnancy is associated with significant physiological changes in the coagulation and fibrinolytic systems with an inclination toward a hypercoagulable state. This includes an increase in plasma levels of most clotting factors, a decrease in endogenous anticoagulants, and inhibition of fibrinolysis. Although these changes are critical in maintaining placental function and reducing postpartum hemorrhage, they may contribute to an increased risk of thromboembolism, particularly toward the end of pregnancy and during puerperium. Hemostasis parameters and the non-pregnant population reference ranges cannot be used in the assessment of bleeding or thrombotic complication risk during pregnancy, and pregnancy-specific information and reference ranges are not always available to support the interpretation of laboratory tests. This review aims to summarize the use of relevant hemostasis tests to promote evidence-based interpretation of laboratory test results as well as discuss challenges associated with testing during pregnancy.

Bloodless surgery in urologic oncology: A review of hematologic, anesthetic, and surgical considerations

The urologic oncology patient who refuses blood transfusion can present unique challenges in perioperative blood management. Since blood loss and associated transfusion can be expected in many complex urologic oncology surgeries, a multidisciplinary approach may be required for optimal outcomes. Through collaboration with the hematologist, anesthesiologist, and urologist, various techniques can be employed in the perioperative phases to minimize blood loss and the need for transfusion. We review the risks and benefits of these techniques and offer recommendations specific to the urologic oncology patient.

Changes in Thrombelastography in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease and the Relationship with Lung Function

Purpose

To analyze the changes in thrombelastography (TEG) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and the relationship with indicators related to lung function.

Methods

100 patients with AECOPD admitted to our hospital from May 2021 to May 2022 were selected as the AE group, and another 80 patients with a stable phase of COPD in the same period were selected as the SP group. Fresh blood specimens were collected from both groups, and TEG-related indicators (R value, K value, α-angle, MA value) were measured using the TEG technique, and lung function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) were measured using a lung function meter, and the correlation between TEG-related indicators and lung function-related indicators was analyzed.

Results

Patients in the AE group had lower R and K values and higher α-angle and MA values than those in the SP group, all with statistically significant differences (P < 0.05). Patients in the AE group had lower FEV1, FVC, FEV1/FVC, and FEV1% levels than those in the SP group, all with statistically significant differences (P < 0.05). Correlation analysis showed that the R value in TEG of AECOPD patients was positively correlated with pulmonary function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) (r = 0.565, 0.529, 0.447, 0.527, all P < 0.001); K value was positively correlated with pulmonary function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) (r = 0.512, 0.567, 0.459, 0.439, all P < 0.001); α-angle was inversely correlated with pulmonary function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) (r = -0.498, -0.372, -0.408, -0.424, all P < 0.001); MA value was inversely correlated with lung function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) (r = -0.459, -0.429, -0.394, -0.403, all P < 0.001).

Conclusion

There is a correlation between TEG-related indicators and lung function-related indicators in AECOPD patients, both of which can guide the diagnosis and treatment process of the disease and are worthy of clinical promotion. The clinical registration number is EA2021086.

Clinical Application of Thromboelastography in Acute Ischemic Stroke

Acute ischemic stroke (AIS), characterized by high morbidity and mortality, has imposed a considerable burden on society. Despite rapid development in the treatment of AIS, there is still a high risk of recurrence. Furthermore, there is a time delay in waiting for the results of conventional coagulation tests in candidate patients for intravenous thrombolysis therapy. Heterogeneous responses to antiplatelet, intravascular thrombolysis, and endovascular therapies also worsen the situation. Thromboelastography (TEG), as a global and portable detection method for hemostasis, facilitates clinicians in disease monitoring, treatment evaluation, and prognosis prediction in AIS. In this narrative review, we provided a comprehensive summary of the clinical application of TEG in ischemic stroke and gave insights to further studies.

Assessment of immediate clotting after flapless extraction using piezosurgery or turbine handpiece in patients receiving dual antiplatelet therapy

PURPOSE

This study aimed to investigate the efficacy of piezosurgery (PI) in promoting immediate clotting after flapless extraction in patients undergoing dual antiplatelet therapy (DAPT).

METHODS

In this randomized controlled trial, 80 DAPT patients were equally divided into the PI and turbine handpiece (TH) groups. Accordingly, flapless extraction of a single tooth using PI or TH was performed on each patient, and the immediate clotting status was evaluated. The results of the preoperative hematological examinations, surgery-related variables and postoperative complications were recorded for analysis.

RESULTS

Both groups presented with low platelet aggregation and similar coagulation functions. The PI group exhibited a higher proportion of patients with normal intra-alveolar clotting (≤30 min) (70% vs. 40%, P = 0.007) and fewer intraoperative complications (25% vs. 47.5%, P = 0.036) than that in the TH group. Logistic regression analysis indicated that the applied instrument was an independent risk factor for prolonged immediate bleeding (odds ratio = 3.10, 95% confidence interval: 1.20-8.00, P = 0.019). Intergroup differences were insignificant in terms of the other surgery-related variables and postoperative complications, except for the longer surgical duration in the PI group.

CONCLUSION

The application of PI may contribute to better immediate clotting in DAPT patients after flapless extraction compared with the use of TH.

Salvianolic acid A alleviates lipopolysaccharide-induced disseminated intravascular coagulation by inhibiting complement activation

Introduction

Disseminated intravascular coagulation (DIC) is a syndrome characterized by coagulopathy, microthrombus, and multiple organ failure. The complement system in DIC is overactivated, and the functions of complement and coagulation pathways are closely related. Our previous screening revealed that salvianolic acid A (SAA) has anti-complement activity. The hyper-activated complement system was involved in the lipopolysaccharide (LPS) induced DIC in rats. The effects of SAA anti-complement action on LPS-induced DIC in rats were investigated.

Methods

The complement activity of the classical pathway and alternative pathway was detected through an in vitro hemolysis assay. The binding sites of SAA and complement C3b were predicted by molecular docking. LPS-induced disseminated coagulation experiments were performed on male Wistar rats to assess coagulation function, complement activity, inflammation, biochemistry, blood routine, fibrinolysis, and survival.

Results

SAA had an anti-complement activity in vivo and in vitro and inhibited the complement activation in the classical and alternative pathway of complement. The infusion of LPS into the rats impaired the coagulation function, increased the plasma inflammatory cytokine level, complemented activation, reduced the clotting factor levels, fibrinogen, and platelets, damaged renal, liver, and lung functions, and led to a high mortality rate (85%). SAA treatment of rats inhibited complement activation and attenuated the significant increase in D-dimer, interleukin-6, alanine aminotransferase, and creatinine. It ameliorated the decrease in plasma levels of fibrinogen and platelets and reversed the decline in activity of protein C and antithrombin III. The treatment reduced kidney, liver, and lung damage, and significantly improved the survival rate of rats (46.2 and 78.6% for the low- and high-dose groups, respectively).

Conclusion

SAA reduced LPS-induced DIC by inhibiting complement activation. It has considerable potential in DIC treatment.

Risk stratification for pregnancy-associated venous thromboembolism: Potential role for global coagulation assays

Risk assessment for venous thromboembolism in pregnancy and the puerperium is currently limited to stratifying clinical surrogate risk factors without high-quality evidence. While the absolute risk of pregnancy-associated venous thromboembolism is low for the vast majority of women, associated morbidity and mortality remains significant. As guidelines for thromboprophylaxis vary widely, some women may be under- or over-anticoagulated, contributing to poor outcomes. New global coagulation assays provide a holistic view of coagulation and may have the potential to detect hypercoagulability in pregnancy, unlike clinically available coagulation assays. However, there are major technical challenges to overcome before global coagulation assays can be realistically proposed as an adjunct to risk assessment for pregnancy-associated venous thromboembolism. This review summarises the literature and controversies in the prediction and prevention of pregnancy-associated venous thromboembolism and outlines the new tools in haematology that may assist in our future understanding of hypercoagulability in pregnancy.

To Investigate Whether Hematocrit Affects Thromboelastography Parameters

Background

Thromboelastogram (TEG) is an experiment to detect coagulation function with whole blood. Red blood cell (RBC) is the most abundant component of blood. Whether RBC has an impact on the results of thromboelastogram? Study Design and Methods. The correlation between hematocrit (HCT) and TEG was analyzed. 17 samples were reconstituted with different HCT. They were tested separately. Correction tests were performed on 17 samples from patients with anemia. HCT was corrected to 0.40 in female and 0.45 in males. The correction formula was determined according to the experimental correction.

Results

HCT was negatively correlated with TEG parameters. As HCT increased, CI and angle decreased (P < 0.05, P < 0.001) and K increased (P < 0.001) in reconstituted samples. In the correction test, the angle measured value was 69.48 ± 4.98 and corrected value was 62.48 ± 6.25, MA measured value was 61.44 ± 7.10 and corrected value was 55.94 ± 7.12, K measured value was 1.45 ± 0.48 and corrected value was 2.11 ± 0.79, and CI measured value was 1.07 ± 1.67 and corrected value was -0.45 ± 1.64. There was a significant difference. The correction formulas of anemia were derived from the experimental correction results. K Correction value = (0.7903∗ A 2 - 2.1803A + 2.8268)∗ K Measured value; Tan angleCorrection value = Tan angleMeasured value/(0.6596∗ A 2 - 1.7478A + 2.4608); MACorrection value = MAMeasured value/(0.1853ln (A) + 1.0197); CICorrection value = -0.6516RMeasured value - 0.3772K Correction value + 0.1224MACorrection value + 0.0759angleCorrection value - 7.7922.

Conclusion

HCT has a negative impact on TEG parameters. Coagulation state of anemia patients is overestimated by TEG. The test results of anemia patients need to be corrected whether through the experimental correction or the formula correction.

Interaction of helminth parasites with the haemostatic system of their vertebrate hosts: a scoping review

Helminth parasitoses are among the most prevalent health issues worldwide. Their control depends largely on unravelling host-parasite interactions, including parasitic exploitation of the host haemostatic system. The present study undertakes a scoping review of the research carried out in this field with the aim of unifying and updating concepts. Multiple keywords combined with Boolean operators were employed to design the literature search strategy. Two online databases were used to identify original peer-reviewed articles written in English and published before 1st January 2020 describing molecular interactions between helminth parasites and the host haemostatic system. Relevant data from the selected sources of evidence were extracted and analysed. Ninety-six publications reporting 259 interactions were selected. Fifty-three proteins belonging to 32 species of helminth parasites were involved in interactions with components of the host haemostatic system. Many of these proteins from both parasite and host were conserved among the different interactions identified. Most of these interactions were related to the inhibition of the coagulation system and the activation of fibrinolysis. This was associated mainly with a potential of parasites to reduce the formation of blood clots in the host and attributed to biological processes, such as parasite nutrition, survival, invasion, evasion and migration or the appearance of pathological mechanisms in the host. A wide range of helminth parasites have developed similar strategies to exploit the haemostatic system of their hosts, which could be regarded as an evolutionary conserved mechanism that could confer benefits to parasites in terms of survival and establishment in their vertebrate hosts.

Acute coronary syndrome in patients with cancer

INTRODUCTION

Improvement in cancer survival has led to an increased focus on cardiovascular disease as the other major determinant of survivorship. As a result, there has been an increasing interest in managing cardiovascular disease during and post cancer treatment.

AREAS COVERED

This article reviews the current literature on the pathogenesis, risk factors, presentation, treatment and clinical outcomes of acute coronary syndrome (ACS) in patients with cancer.

EXPERT OPINION

There is growing evidence that both medical therapy and invasive management of ACS improve outcomes in patients with cancer. Appropriate patient selection, risk stratification and tailored therapy represents the cornerstone of management in these patients.

Study on the Interaction between Deuterium Clopidogrel and Omeprazole

<b><i>Introduction:</i></b> Dual antiplatelet therapy with aspirin in combination with a P2Y₁₂ receptor antagonist is a cornerstone for treating patients with acute coronary syndrome and in percutaneous coronary intervention. However, as this combination of antiplatelet therapy increases the risk of bleeding, proton pump inhibitors (PPIs) are currently recommended to prevent gastrointestinal ulcers and bleeding. The cytochrome P450 (CYP450) isoenzyme system metabolizes both clopidogrel (CLP) and PPIs. Unfortunately, omeprazole (OM) reduce the antiplatelet activity of CLP and increases the probability of recurrence of cardiovascular events by competitively inhibiting the CYP450 isoenzyme CYP2C19. <b><i>Methods:</i></b> To address these abovementioned problems, we designed and synthesized deuterium CLP (D-CL) using selective deuterium technology. Our previous research results showed that D-CL had better pharmacokinetic and pharmacodynamic properties. Thus, the HPLC-MS/MS method, cocktail method, Born method, electro-stimulated thrombus generation, and thrombus elastography were used to detect the production of thiol active metabolites (AM), CYP450 enzyme activities, platelet aggregation, time and length of thrombus formation, and the maximum clot strength after combination therapy. We investigated the pharmacokinetics and pharmacodynamics properties of D-CL combined with OM. <b><i>Results:</i></b> As compared to CLP, D-CL was less affected when combined with OM, which was reflected in lower inhibitory effects of CYP450 enzyme activities, a greater area under the curve of AM, and better antiplatelet and antithrombotic effects. <b><i>Conclusion:</i></b> D-CL may reduce drug-drug interactions and address the clinical disadvantages of CLP.

Ex vivo evaluation of blood coagulation on endothelial glycocalyx-inspired surfaces using thromboelastography

Purpose

Present blood-contacting materials have not yet demonstrated to be effective in reducing blood coagulation without causing additional side effects clinically. We have developed an endothelial glycocalyx-inspired biomimetic surface that combines nanotopography, heparin presentation, and nitric oxide (NO)-releasing features. The resulting modified surfaces have already shown promise in reducing unfavorable blood-material interactions using platelet-rich plasma. In this study, the efficacy of modified surfaces for reducing coagulation of human whole blood was measured. In addition, the effects of leached polysaccharides and chemical modification of the modified surfaces were evaluated.

Methods

Leached polysaccharides in the incubation solution were detected by a refractive index method to determine the potential influences of these modified surfaces on the blood coagulation observation. Chemical modifications by the nitrosation process on the polysaccharides in the modified surfaces were detected using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Clot formation parameters were measured using thromboelastography (TEG), a clinically relevant technique to evaluate whole blood coagulation.

Results

No polysaccharides were detected in the heparinized polyelectrolyte multilayer-coated titania nanotube array surface (TiO2NT + PEM) incubation solution; however, polysaccharides were detected from NO-releasing TiO2NT + PEM surface (TiO2NT + PEM + NO) incubation solution both after the nitrosation process and after all NO was released. The structures of thiolated chitosan and heparin were altered by t-butyl nitrite. All heparin-containing surfaces were shown to slow or inhibit clot formation.

Conclusion

This study is the first to evaluate these endothelial glycocalyx-inspired surfaces using clinically relevant parameters, as well as proposing potential influences of these modified surfaces on the inhibition of clot formation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44164-021-00001-w.

Assessment of Risk Factors and Cognitive Level Associated with Venous Thrombosis Patients in a Coexistence of Multiple Diseases Study in Shanghai

Background

Venous thrombosis (VTE) is a high-incidence disease that affects different systems of the body, but no comparative studies have been conducted to explore its incidence in different systems in patients with the coexistence of multiple diseases. Primary care is a medical institution that has the first contact with patients’ conditions. The majority of outpatients suffer from multiple diseases, and they are more prone to VTE, which is of significance and requires investigation. At the same time, we observed that the primary care patients’ cognition level of VTE is insufficiency at present, and the prevention and management of VTE in China is still in its infancy. Most studies focus on whether doctors and nurses are clear about the diagnosis and manifestations of VTE, however, few studies on patients’ cognitive level and influencing factors of symptoms and prevention of VTE. Therefore, it is necessary to study the causes of cognitive deficiency of VTE from the perspective of patients, conduct targeted cognitive and behavioral interventions, and finally achieve the purpose of improving the effect of VTE prevention and management.

Aim

This study aimed to explore the risk factors, cognitive level and cognitive potential influence factors of VTE in outpatients of primary care in Shanghai, as well as which diseases, are more likely to promote occurrence of VTE among patients with multiple diseases.

Methods

A total of 710 patients were included in the analysis. Shanghai in China is divided into urban and suburban areas by their geographical location, and a random sample of 10 primary care areas was investigated, including 5 urban areas and 5 suburban areas. The Padua scale and the VTE cognitive level-related knowledge test scale were used for the investigation. Statistical software was used to conduct univariate Pearson correlation analysis and multivariate logistic regression analysis for VTE high-risk factors among outpatients of primary care. Furthermore, the high-risk factors for VTE and the types of chronic disease in patients with multiple diseases were subjected to subgroup analyses. t-test was used to statistically analyze cognitive level of VTE and the potential influence factors related to the patients’ VTE cognitive level.

Results

Univariate analysis of risk factors for VTE in 710 outpatients showed that age (χ²=83.895, P<0.001), education (χ²=8.324, P=0.004), region (χ²=63.936, P<0.001), chronic disease (χ²=18.198, P<0.001) and the coexistence of multiple diseases (χ²=61.347, P<0.001) were the main risk factors for VTE risk in patients. Logistic multivariate regression analysis showed that age, region, chronic diseases and the coexistence of multiple diseases were independent risk factors for VTE risk in patients. The correlation between high risk of VTE in patients with multiple diseases and various types of chronic diseases was further analyzed by logistic multivariate regression. The results showed that diabetes mellitus (OR=1.636 [95% CI, 1.030–2.599], P=0.037), cerebral infarction (OR=8.484 [95% CI, 4.615–15.597], P<0.001), coronary heart disease (OR=2.987 [95% CI, 1.699–5.252], P<0.001), intracerebral hemorrhage (OR=15.130 [95% CI, 4.707–48.630], P<0.001), respiratory diseases (OR=3.470, [95% CI, 1.428–8.43], P=0.006) and malignant tumors (OR=4.576, [95% CI, 1.85–11.315], P=0.001) were independent risk factors for VTE among patients with co-existing diseases, and the risks from high to low were cerebral hemorrhage>cerebral infarction>malignant tumor>respiratory system disease>coronary heart disease> diabetes. In addition, patients’ age (t=6.869, P<0.001), region (t=3.420, P<0.001), education level (t=−7.341, P<0.001), chronic disease (t=5.875, P<0.001), BMI (t=6.404, P=0.012), smoking (t=4.152, P=0.042) were related to the VTE cognitive level.

Conclusion

General practitioners should pay close attention to independent risk factors for VTE among patients in routine outpatient care, especially patients with co-existing diseases with independent risk for VTE, placing them high risk of VTE. At the same time, health education and other measures should be strengthened to improve the patients’ awareness and cognitive level of VTE to prevent the occurrence of VTE and its related complications.

Establishment of Normal Range for Thromboelastography in Healthy Middle-Aged and Elderly People of Weihai in China

TEG can monitor the dynamic changes of blood clot formation and lysis by activating the coagulation system of a small sample of whole blood in vitro. The parameters can reflect the level of coagulation factors, the function of fibrinogen and platelet, and the presence or absence of hyperfibrinolysis. At present, the normal reference range of the parameters of TEG is mainly based on the reference values established by the Western population. Due to the differences in the distribution of ethnic groups, many countries have established their reference ranges for healthy populations. In China, some scholars have tried to establish the corresponding TEG reference range according to the characteristics of the population in different regions. This study tried to establish the reference range for thromboelastography in healthy middle-aged and elderly people of Weihai in China and compare it with the reference range provided by the manufacturer. The fasting venous blood of 454 healthy middle-aged and elderly people was collected, including 239 males and 215 females. The thromboelastography TEG-5000 was used to measure the reaction time (R), coagulation formation time (K), coagulation angle (Angle), and maximum amplitude (MA). The reference range of TEG parameters of middle-aged and elderly healthy males was R: 4.38–8.27 min, K: 1.44–2.82 min, Angle: 48.53–72.17 deg, and MA: 51.95–72.02 mm; respectively, in the females, the normal value was R: 3.43–7.40 min, K: 1.07–2.53 min, Angle: 48.22–77.22 deg, and MA: 53.10–74.58 mm; The difference of R, K, Angle, and MA between the male group and the female group was statistically significant (P < 0.05); In this study, if we use the reference range established by the manufacturer, the R specificity for males was 91.6%, K specificity was 98.7%, Angle specificity was 85.8%, and MA specificity was 93.7%; the range for females was 68.4%, 99.5%, 75.8%, and 87.4%, respectively. There are statistically significant differences between R, K, Angle, and MA in middle-aged and elderly healthy women and men. It is necessary to establish a TEG reference range for healthy females and males.

In-vitro thromboelastographic characterization of reconstituted whole blood utilizing cryopreserved platelets

Conducting in-vitro thrombosis research presents numerous challenges, the primary of which is working with blood products, whether whole blood or fractionated whole blood, that have limited functional shelf-lives. As a result, being able to significantly prolong the clotting functionality of whole blood via fractionation and recombination promises greater accessibility via resource minimization in the realm of thrombosis research. Whole blood with CPDA1 from healthy volunteers was fractionated and stored as frozen platelet-free plasma (PFP, -20°C), refrigerated packed red blood cells (pRBCs, 4°C) and cryopreserved platelets (-80°C). Subsequent recombination of the above components into their native ratios were tested via thromboelastography (TEG) to capture clotting dynamics over a storage period of 13 weeks in comparison to refrigerated unfractionated WB+CPDA1. Reconstituted whole blood utilizing PFP, pRCBs and cryopreserved platelets were able to maintain clot strength (maximum amplitude) akin to day-0 whole blood even after 13 weeks of storage. Clots formed by reconstituted whole blood exhibited quicker clotting dynamics with nearly two-fold shorter R-times and nearly 1.3-fold increase in fibrin deposition rate as measured by TEG. Storage of fractionated whole blood components, in their respective ideal conditions, provides a means of prolonging the usable life of whole blood for in-vitro thrombosis research. Cryopreserved platelets, when recombined with frozen PFP and refrigerated pRBCs, are able to form clots that nearly mirror the overall clotting profile expected of freshly drawn WB.

Clinical correlation between coagulation disorders and sepsis in patients with liver failure

OBJECTIVE

This study aimed to explore the clinical detection and prognosis of coagulation function in patients with liver failure and sepsis.

METHODS

The plasma fibrinogen (FIB), factor II, factor VII, factor V, factor IV, antithrombin III (ATIII), platelet (PLT), mean PLT volume (MPV), D-dimer, prothrombin activity (PTA), and fibrin degradation product (FDP) levels and thromboelastogram values were detected in patients with liver failure complicated with sepsis and compared with those in the liver failure and liver cirrhosis groups. The patients with liver failure complicated with sepsis were analyzed by univariate and multivariate logistic regression, and the regression equation was established.

RESULTS

The levels of FIB, factor II, factor VII, factor V, ATIII, PLT, MPV, D-dimer, and FDP in the patients with liver failure complicated with sepsis were compared with those in the control group patients, and the differences were statistically significant (p <  0.05). Among the thromboelastography parameters in the patients with liver failure and sepsis, the differences in the K-value, R-value, angle, maximum amplitude, and coagulation index values compared with those of the control group were statistically significant (p <  0.05). The logistic regression model obtained was as follows: p = 1/(1 + e [-0.128×X1-0.058×X2 + 0.211×X3 + 0.2×X4 + 0.25]). The specificity, sensitivity, and accuracy values of the regression equation in determining the prognosis were 92%, 93.9%, and 92.8%, respectively. Among the 11 factors, factor VII, PLT, FDP, and D-dimer were included in the regression equation.

CONCLUSION

Coagulation disorder is exacerbated in patients with liver failure and sepsis. Among the 11 coagulation-related factors, factor VII, PLT, FDP, and D-dimer may be the independent factors influencing the prognosis of patients with acute liver failure and sepsis.

Thromboelastometry assessment of hemostatic properties in various murine models with coagulopathy and the effect of factor VIII therapeutics

BACKGROUND

Rotational thromboelastometry (ROTEM) has been commonly used to assess the viscoelastic properties of the blood clotting process in the clinic for patients with a hemostatic or prothrombotic disorder.

OBJECTIVE

To evaluate the capability of ROTEM in assessing hemostatic properties in whole blood from various mouse models with genetic bleeding or clotting disease and the effect of factor VIII (FVIII) therapeutics in FVIIInull mice.

METHODS

Mice with a genetic deficiency in either a coagulation factor or a platelet glycoprotein were used in this study. The properties of platelet- or plasma-FVIII were also assessed. Citrated blood from mice was recalcified and used for ROTEM analysis.

RESULTS

We found that blood collected from the vena cava could generate reliable results from ROTEM analysis, but not blood collected from the tail vein, retro-orbital plexus, or submandibular vein. Age and sex did not significantly affect the hemostatic properties determined by ROTEM analysis. Clotting time (CT) and clot formation time (CFT) were significantly prolonged in FVIIInull (5- and 9-fold, respectively) and FIXnull (4- and 5.7-fold, respectively) mice compared to wild-type (WT)-C57BL/6J mice. Platelet glycoprotein (GP)IIIanull mice had significantly prolonged CFT (8.4-fold) compared to WT-C57BL/6J mice. CT and CFT in factor V (FV) Leiden mice were significantly shortened with an increased α-angle compared to WT-C57BL/6J mice. Using ROTEM analysis, we showed that FVIII expressed in platelets or infused into whole blood restored hemostasis of FVIIInull mice in a dose-dependent manner.

CONCLUSION

ROTEM is a reliable and sensitive assay for assessing therapeutics on hemostatic properties in mouse models with a bleeding or clotting disorder.

Thrombotic activation before and after total hip arthroplasty. A prospective cohort study

BACKGROUND

Total hip arthroplasty (THA) causes acute blood loss. It may lead to a deficiency in coagulation factors, which, in turn, may lead to increased bleeding during the postoperative period.

METHODS

Thirty patients (18 women) with a mean age of 67 years (range: 63-72 years) participated in this prospective diagnostic study. THA was performed without tranexamic acid administration in the perioperative period. Activities of clotting factors II, VIII, X, and fibrinogen concentration were evaluated before surgery, 6 hours after the procedure, 2, 4, and 6 days after the operation. All laboratory tests were performed using ACL TOP 500 CTS analyzer.

RESULTS

No thromboembolic complications were noted during hospitalization. Mean fibrinogen concentration was 366 mg/dL before surgery, which decreased to 311 mg/dL 6 hours after the operation and peaked at 827 mg/dL on the 4th day after the procedure. Activities of factors II and X decreased on the second and fourth days after surgery. Although the activity of factor VIII decreased after the procedure, it remained within the normal range. Increased baseline fibrinogen concentrations were observed in 6 out of 30 (20%) patients. Mean blood loss was 1332 mL (range, 183-2479 mL) and did not correlate with changes in clotting factor activities.

CONCLUSIONS

In patients undergoing THA, fibrinogen acts as an acute-phase protein. Activities of clotting factors II and X normalize within 6 days, and although the activity of factor VIII decreases, it remains within the normal range.

TRIAL REGISTRATION

The study was pre-registered May 1st, 2020 on ClinicalTrials.gov.

Effect of unfractionated heparin and low molecular weight heparin on the clotting of platelet-reduced whole blood: an in-vitro study utilizing thromboelastography

Treatment of venous thromboembolism with concomitant thrombocytopenia is challenging. The platelet threshold for safe administration of anticoagulants is under debate, with minimum platelet count of 50 × 109/l being recommended as the safe cutoff. However, some evidence suggests administration of anticoagulants may still be safe at platelet levels of 30 × 109/l. Therefore, we developed an in-vitro thromboelastography (TEG) study to examine the effect of therapeutic or prophylactic levels of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) on the clotting profile of platelet-reduced whole blood. Using magnetic bead-based antibody chromatography, platelets were removed to achieve platelet-depleted blood (<10 × 109/l of platelets). Platelet-depleted blood was then mixed with whole blood to produce blood samples with platelet counts of 30 × 109, 50 × 109 and 150 × 109/l. These blood samples were incubated with therapeutic or prophylactic levels of UFH or LMWH in disposable TEG cups. Clotting was initiated with 10 mmol/l calcium and optimized tissue factor levels for each anticoagulant used (2.25 pmol/l for UFH and 2.05 pmol/l for LMWH). Clotting was monitored by TEG at 37 °C for 180 min. The following TEG parameters were evaluated: R (time to clot), maximum amplitude (strength of clot) and area under the curve in 15 min (overall speed and strength of the clot at 15 min of clotting). No statistically significant differences were observed between platelet counts of 30 × 109 and 50 × 109/l for R, maximum amplitude or area under the curve in 15 min for most of the therapeutic and prophylactic doses of UFH and LMWH tested in this study. Use of anticoagulants compromised all of the TEG parameters relative to a normal platelet count of 150 × 109/l, in a dose dependent manner. The current study demonstrates that in-vitro clotting is impaired with use and increasing doses of anticoagulants. Despite this observation, we did not observe a significant difference in clotting between platelet levels of 30 × 109 and 50 × 109/l. Overall, this work provides further insight in the debated use of anticoagulants in patients with venous thromboembolism and concomitant thrombocytopenia, and provides support for possible use of anticoagulants at lower platelet thresholds.

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.

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.

Role of thromboelastography in the evaluation of septic shock patients with normal prothrombin time and activated partial thromboplastin time

Coagulopathy is frequent in septic shock and plays a key role in multiple organ dysfunction. The aim of this study is to investigate application values of thromboelastography (TEG) for outcome in septic shock patients with a normal value of prothrombin time (PT) and active partial thromboplastin time (aPTT). Prospective observational study using 1298 consecutive septic shock patients with TEG at admission was conducted at the emergency department (ED) of a tertiary care hospital in South Korea between 2016 and 2019. After excluding overt-disseminated intravascular coagulation (DIC) defined by scoring system, we included patients with a normal value of international normalized ratio ≤ 1.3 and aPTT ≤ 34 s. The primary outcome was 28-day mortality. 893 patients were included and 129 patients with overt DIC were excluded. Of the 764 remaining patients, 414 (54.2%) patients showed normal PT and aPTT (28-day mortality rate, 11.4%). TEG values such as reaction time, kinetic time (K), alpha angle (α), maximum amplitude (MA) and lysis index (LY 30) showed no significant mean difference between the survivor and non-survivor groups. However, hypocoagulable TEG values such as α < 53° (12.0% vs. 23.4%; p = 0.039), and MA < 50 mm (6.3% vs. 21.3%; p = 0.002) were significantly higher in the non-survived group. In multivariate analysis, hypocoagulable state (defined as K > 3 and α < 53 and MA < 50) was independent factors associated with increased risk of death (OR 4.882 [95% CI, 1.698–14.035]; p = 0.003). In conclusion, septic shock patients with normal PT and aPTT can be associated with impaired TEG profile, such as hypocoagulability, associated with increased mortality.

Net platelet clot strength of thromboelastography platelet mapping assay for the identification of high on-treatment platelet reactivity in post-PCI patients

High-on treatment platelet reactivity (HTPR) leads to more prevalence of thrombotic event in patients undergoing percutaneous coronary interventions (PCI). Dual antiplatelet therapy with aspirin in addition to one P2Y₁₂ inhibitor is commonly administrated to reduce HTPR. However, ‘one size fits all’ antiplatelet strategy is widely implemented due to lacking benefits with tailored strategy. One reason for the failure of tailored treatment might be less specificity of the current indicators for HTPR. Therefore, searching for specific indicators for HTPR is critical. Thromboelastograph with platelet mapping (TEGpm) assay has been explored for identifying HTRP. Variables of TEGpm assay, including maximum amplitude (MA) induced by thrombin (MAthrombin), R time, platelet aggregation rate induced by ADP (TEGaradp) and MA induced by ADP (MAadp) have been demonstrated to be able to identify HTPR in post-PCI patients. However, these variables for HTPR might be less specific. Thus, in the present study, a novel variable nMAadp was derived by removing fibrin contribution from MAadp and analyzed for its usefulness in determining HTPR. In addition, MAthrombin, R time, MAadp and TEGaradp were also examined for determining HTPR. In conclusion, nMAadp and TEGaradp were demonstrated to be independent indicators for HTPR; nMAadp had the strongest power to identify HTPR with cutoff value of 26.3 mm; MAthrombin and R time were not significantly different between patients with and without HTPR; combination of TEGaradp and nMAadp further improved the ability to identify HTPR with an AUC of 0.893.

Comparison of VerifyNow, thromboelastography, and PL-12 in patients with minor ischemic stroke or transient ischemic attack

High on-treatment platelet reactivity (HOPR) is associated with stroke recurrence. It is important to find a reliable method to assess HOPR. We aimed to compare the correlations between VerifyNow™ system, thromboelastography (TEG), and Aggrestar platelet function analyzer (PL-12) on platelet activity in patients with minor ischemic stroke or transient ischemic attack (TIA) after dual antiplatelet therapy for 7 days. About 276 patients were included. Spearman’s correlation coefficient and the kappa coefficient were adopted to evaluate associations among the three test methods. An obvious correlation between VerifyNow and TEG on HOPR-ADP (r=0.64, p<0.001) was found. The correlations of HOPR-ADP between PL-12 and the other two platelet function analyzers were moderate (PL-12 versus VerifyNow, r=0.47, p<0.001; PL-12 versus TEG, r=0.25, p<0.001). The correlations of HOPR-AA were limited among these three platelet function analyzers (VerifyNow versus TEG, r=0.09, p=0.14; VerifyNow versus PL-12, r=0.15, p=0.01; PL-12 versus TEG, r=0.10, p=0.09). Correlations among different platelet function analyzers were varied. VerifyNow and TEG were more correlative than PL-12 on HOPR-ADP. The consistence of HOPR-AA was limited among VerifyNow, TEG and PL-12. The proportion of stroke recurrence and composite events in patients with HOPR-ADP assessing by PL-12 was higher than VerifyNow and TEG.

Analyzing coagulation dynamics during treatment of vascular malformations with thromboelastography

BACKGROUND/OBJECTIVES

Slow-flow vascular malformations are abnormal vessels that can lead to activation and consumption of coagulation factors and thrombosis, known as localized intravascular coagulopathy (LIC). Most clinical and research evidence of vascular malformation hemostasis relies on conventional coagulation studies, which may not provide a complete picture. Thromboelastograpy (TEG) is a tool that can provide real-time assessment of a patient's coagulation dynamics, and may allow for a more individualized treatment approach. We hypothesized that patients with slow-flow vascular malformations will have changes in TEG parameters peri-procedure that will help predict blood product or medication administration.

DESIGN/METHODS

Institutional Review Board approved prospective study of patients with slow-flow vascular malformations undergoing a sedated, minor procedure. TEG and conventional coagulation studies were obtained preprocedure, 15 min, and when possible, at 30 min after the start of the procedure.

RESULTS

Twenty-five patients were enrolled. Median age was 15 years (range 3-47 years). Procedures included laser and/or sclerotherapy. There were no changes in TEG parameters from baseline to 15 min or 30 min. The following decreased from baseline to 15 min: fibrinogen 313 to 287 mg/dL (P = .001), D-dimer 1.3 to 1.1 mg/L (P = .02), hemoglobin 12.8 to 11.8 g/dL (P = .001), and platelet count 272 000 to 256 000 (P = .006). No patient had a bleeding/thrombotic complication during or within 1 week postprocedure.

CONCLUSION

We saw no change in TEG parameters or bleeding or clotting complications despite significant numerical changes in conventional coagulation profiles, suggesting that conventional studies may not be as useful in determining risks of bleeding or thrombotic complications peri-procedure for minor procedures.

Role of Thromboelastography as an Early Predictor of Disseminated Intravascular Coagulation in Patients with Septic Shock

(1) Background: The currently proposed criteria for diagnosing overt disseminated intravascular coagulation (DIC) are not suitable for early detection of DIC. Thromboelastography (TEG) rapidly provides a comprehensive assessment of the entire coagulation process and is helpful as a guide for correcting consumptive coagulopathy in sepsis-induced DIC. This study aimed to investigate the role of TEG in the prediction of DIC in patients with septic shock. (2) Methods: TEG was conducted prospectively in 1294 patients with septic shock at the emergency department (ED) between January 2016 and December 2019. After exclusion of 405 patients with “do not attempt resuscitation” orders, those refusing enrollment, and those developing septic shock after ED presentation, 889 patients were included. DIC was defined as an International Society on Thrombosis and Hemostasis score ≥ 5 points within 24 h. (3) Results: Of the 889 patients with septic shock (mean age 65.6 ± 12.7 years, 58.6% male), 158 (17.8%) developed DIC. TEG values, except lysis after 30 min, were significantly different between the DIC and non-DIC groups. Among the TEG values, the maximal amplitude (MA) had the highest discriminating power for DIC, with an area under the curve of 0.814. An MA < 60 indicated DIC with 79% sensitivity, 73% specificity, and 94% negative predictive value. Based on multivariable analysis, MA < 60 was an independent predictor of DIC (odds ratio 5.616 (95% confidence interval: 3.213–9.818)). (4) Conclusions: In patients with septic shock, the MA value in TEG could be a valuable tool for early prediction of DIC.

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.

A comparison of three platelet function tests in ischemic stroke patients with antiplatelet therapy

Predicting the effectiveness of antiplatelet drugs is critical to precision antiplatelet therapy. However, there is a lack of an acceptable method, although there are a variety of methods for detecting platelet function. In this study, we compared three major platelet function tests to assess their performance and found better methods for platelet function evaluation after aspirin or clopidogrel treatment in ischemic stroke patients by comparative study. A total of 249 ischemic stroke patients were enrolled who were treated with aspirin or clopidogrel or both. Three platelet function tests including light transmittance aggregometry (LTA), thromboelastography (TEG), platelet function analyzer (PFA) were performed as well as CYP2C19 genotype determination. Correlation analyses and kappa statistics were used. All three methods were effective in evaluating aspirin function. However, only LTA and TEG had good correlation and consistency (r = -0.37, kappa = 0.634). TEG-ADP was the least sensitive for clopidogrel, as the platelet inhibition ratio did not differ between the clopidogrel-user group and the control (P = 0.074), while LTA and PFA were sensitive (P ＜ 0.001). Correlations between platelet assays were poor for clopidogrel (the absolute value of r range from 0.13 to 0.35) and so was the agreement (Kappa from 0.232 to 0.314). LTA and PFA have a good correlation with CYP2C19 genotyping (P = 0.034 and 0.014). In conclusion, all three tests were able to evaluate aspirin effect, LTA-AA and TEG-AA had a good correlation. TEG perform badly for clopidogrel effect detection. The fair-to-modest agreement among assays indicated further study was indispensable.

Ability of Thromboelastography to Detect Hypercoagulability: A Systematic Review and Meta-Analysis

OBJECTIVE

To review the current literature on the use of viscoelastic hemolytic assays, such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM), during the perioperative period of patients and determine the ability of TEG and ROTEM to detect hypercoagulability and identify increased risk of the development of venous thromboembolism (VTE).

DATA SOURCES

PubMed, EMBASE, and Cochrane online databases were queried through February 11, 2018, by pairing the terms "thromboelastography," "viscoelastic hemostatic assays," and "rotational thromboelastometry" with "venous thromboembolism," "deep vein thrombosis," "pulmonary embolism," and "hypercoagulability."

STUDY SELECTION

Inclusion and exclusion criteria were established to determine relevance and quality of data, of which 2.54% of initially identified studies met.

DATA EXTRACTION AND SYNTHESIS

Articles and citations were reviewed for relevance by 2 independent individuals following PRISMA guidelines as well as a quality assessment of data as established by Zaza et al. In studies that separated patients postoperatively by VTE development or no VTE development, data were pooled utilizing a modified DerSimmion and Laird random effects model.

RESULTS

One thousand eight hundred ninety-three articles were assessed for eligibility, yielding 370 abstracts. Of the 370 abstracts, 35 studies were included, and of these, only 5 were included in the meta-analysis. Studies included postsurgical patients in a variety of surgical fields, encompassing a total of 8939 patients, with 717 thrombotic events reported. Elevated maximum amplitude (MA) was a statistically significant indicator of hypercoagulability across at least 1 perioperative time point in 17 (50%) of the articles reviewed, consisting of 6348 (72%) patients. The pooled mean MA value for defining hypercoagulability was greater than 66.70 mm. Using a prepublished value for hypercoagulability of 65 mm, the combined effect of MA on the development of VTE in postsurgical patients was determined to be 1.31 (95% confidence, 0.74-2.34, P = 0.175) and was 46% sensitive and 62% specific in predicting a postoperative VTE.

CONCLUSIONS

Only 1 parameter, MA, was consistently used to both define hypercoagulability and be predictive of VTE after traumatic injury and surgical intervention; however, there remains a broad variability in the definition of hypercoagulability as determined by MA and thus limits its predictive ability. In addition, when hypercoagulability was measured throughout the perioperative period, TEG consistently demonstrated hypercoagulability starting on post-op day 1 (POD1).

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

[Thromboelastography-based assessment of coagulation function in patients with chronic kidney disease and the risk factors of hypercoagulability]

OBJECTIVE

To assess the changes in the coagulation profiles of patients with chronic kidney disease (CKD) using thromboelastography (TEG) and identify the risk factors of hypercoagulation in CKD patients.

METHODS

A total of 128 patients with CKD admitted in Hunan Provincial People's Hospital between August, 2018 and May, 2019 were recruited. The results of conventional coagulation test and TEG were compared between patients with CKD and 21 healthy control adults. The patients with CKD were divided into hypercoagulation group with a maximum amplitude (MA) &gt; 68 mm (n=66) and non-hypercoagulation group (MA≤68 mm, n=62). The laboratory indicators were compared between the groups, and the factors affecting the hypercoagulable state in patients with CKD were analyzed.

RESULTS

The levels of fibrinogen and D-Dimer increased significantly in patients with CKD at different stages as compared with the control subjects (P &lt; 0.05). In the patients with CKD, the reaction time and K time decreased while MA, α-angle and coagulation index increased significantly in patients in stage 3-4 and those in stage 5 either with or without hemodialysis compared with the control group (P &lt; 0.05). The estimated glomerular filtration rate (eGFR), percentage of patients with diabetes mellitus, history of stroke, percentage of neutrophils, neutrophil-lymphocyte ratio, red blood cell count, hemoglobin levels, platelet count, serum creatinine, serum cystatin-C, serum albumin, and lipoprotein (a) all differed significantly between hypercoagulation group and non-hypercoagulation group (P &lt; 0.05). The eGFR, platelet count and hemoglobin levels were identified as independent factors affecting hypercoagulability in patients with CKD (P &lt; 0.05).

CONCLUSIONS

s The hypercoagulable state of patients with CKD worsens gradually with the disease progression, and eGFR, platelet count and hemoglobin levels are all risk factors for the hypercoagulable state in patients with CKD.

Establishment of thromboelastography reference intervals by indirect method and relevant factor analyses

Thromboelastography (TEG) as a global coagulation test has been continuously developed for many decades in either research or clinical practice. The versatility of TEG test leads to difficulty in standardization and result interpretation. Reference intervals (RIs) of TEG may be one of the most controversial factors that influence its wide applications. RIs establishment with the traditional method is time‐consuming and laborious as well as beyond general laboratory capability. Indirect method using stored data and with statistical calculation and small cost is emerging as an alternative approach for RIs determination. Gender, age, or both affect RIs and must be taken into account before RIs estimation. The present study retrospectively collected a total of 930 TEG results as subjects and established RIs with indirect method for Kaolin‐activated TEG, including the parameters of R, K, αAngle, MA, and CI. Furthermore, gender, age, and gender‐dependent age subsets analyses were performed to determine their effects on RIs of TEG. In this study, we found that TEG parameters showed more hypercoagulability in female than male, most of the measured TEG variables were significantly associated with aging, but only in male statistical significance was found among different age stratification and 60‐year‐old could be considered as cutting point to differentiate coagulation ability in male. In addition, RIs of TEG were estimated by indirect method suitably and verified to be valid in our study. Finally, the RIs of TEG by indirect method were basically significantly different to the RIs recommended by manufacturer, but the consistent percentage is relatively high in the most of measured parameters. In conclusion, it is suggestive that the indirect method for RIs establishment is feasible, but relevant factors, such as gender and age, specifically gender‐dependent age effect, should be considered before RIs determinations.

Evaluating medical device and material thrombosis under flow: current and emerging technologies

This review highlights the importance of flow in medical device thrombosis and explores current and emerging technologies to evaluate dynamic biomaterial Thrombosis in vitro.