Thrombelastography

Acetylsalicylic acid alone or in combination with either enoxaparin or unfractionated heparin for postoperative thromboprophylaxis in coronary artery bypass surgery patients. A randomised clinical trial assessing surrogate outcomes

INTRODUCTION

Coronary artery bypass graft surgery has considerable effects on patient haemostasis. Heparins as thromboprophylaxis may be beneficial but may also increase the risk of bleeding complications.

OBJECTIVES

To assess the effects of heparins on haemostasis in post-coronary artery bypass graft patients.

METHODS

Across one year, we randomised 60 participants scheduled for an elective coronary artery bypass graft-procedure with or without aortic valve replacement. The trial was a prospective, open-label (though blinded for the laboratory), randomised, single-centre trial with three intervention groups (n = 20 in each): group 1 received acetylsalicylic acid, group 2 received subcutaneous low molecular weight heparin and acetylsalicylic acid, and group 3 received intravenous unfractionated heparin and acetylsalicylic acid. Primary outcomes were platelet activation (Multiplate® ASPI-test) and time to clot initiation (TEG® R-time). We secondly assessed several additional Multiplate® and TEG® parameters.

RESULTS

Group 3 (intravenous unfractionated heparin) compared with group 1 (acetylsalicylic acid alone) showed evidence of 1) increased clot initiation time (R-time + 0.9 min; 95 % CI: +0.4 to +1.4 min; P = 0.009), and 2) decreased 30-min lysis (-1.3 %; 95 % CI: -2.1 to -0.5 %; P = 0.02). The remaining analyses of primary and secondary outcomes showed no evidence of a difference between the three groups.

DISCUSSION

Intravenous unfractionated heparins may increase the clot initiation time post-operatively after coronary artery bypass graft surgery and reduce lysis. Otherwise, there seems to be no effect of low molecular weight or unfractionated heparin on haemostatic parameters after coronary artery bypass surgery patients.

Thromboelastography as an early prediction method for hypofibrinogenemia in emergency department patients with primary postpartum hemorrhage

BACKGROUND

Timely and accurate assessment of coagulopathy is crucial for the management of primary postpartum hemorrhage (PPH). Thromboelastography (TEG) provides a comprehensive assessment of coagulation status and is useful for guiding the treatment of hemorrhagic events in various diseases. This study aimed to evaluate the role of TEG in predicting hypofibrinogenemia in emergency department (ED) patients with primary PPH.

METHODS

We conducted a retrospective observational study in the ED of a university-affiliated tertiary hospital between November 2015 and August 2023. TEG was performed upon admission. The cutoff value for hypofibrinogenemia was 200 mg/dL. The primary outcome was the presence of hypofibrinogenemia.

RESULTS

Among the 174 patients, 73 (42.0%) had hypofibrinogenemia. The need for massive transfusion was higher in the hypofibrinogenemia group (37.0% vs. 5.0%, p < 0.001). Among the TEG parameters, all values were significantly different between the groups, except for lysis after 30 min, suggesting a tendency toward hypocoagulability. Multivariable analysis revealed that the alpha angle (odds ratio (OR) 0.924, 95% confidence interval (CI) 0.876-0.978) and maximum amplitude (MA) (OR 0.867, 95% CI 0.801-0.938) were independently associated with hypofibrinogenemia. The optimal cutoff values for the alpha angle and maximum amplitude (MA) for hypofibrinogenemia were 63.8 degrees and 56.1 mm, respectively.

CONCLUSION

Point-of-care TEG could be a valuable tool for the early identification of hypofibrinogenemia in ED patients with primary PPH.

Acute liver failure

Acute liver failure (ALF) is a life-threatening disorder characterised by rapid deterioration of liver function, coagulopathy, and hepatic encephalopathy in the absence of pre-existing liver disease. The cause of ALF varies across the world. Common causes of ALF in adults include drug toxicity, hepatotropic and non-hepatotropic viruses, herbal and dietary supplements, antituberculosis drugs, and autoimmune hepatitis. The cause of liver failure affects the management and prognosis, and therefore extensive investigation for cause is strongly suggested. Sepsis with multiorgan failure and cerebral oedema remain the leading causes of death in patients with ALF and early identification and appropriate management can alter the course of ALF. Liver transplantation is the best current therapy, although the role of artificial liver support systems, particularly therapeutic plasma exchange, can be useful for patients with ALF, especially in non-transplant centres. In this Seminar, we discuss the cause, prognostic models, and management of ALF.

The Value of Serum Procalcitonin, Thromboelastography Combined with Platelet Count in Predicting the Short-Term Progression of Septic Shock in the Intensive Care Unit

Objective

By evaluating the level of serum procalcitonin (PCT), thromboelastography (TEG) and platelet count (PLT) of patients with septic shock in intensive care unit (ICU), the predictive value of the combination of the three indicators on the short-term progression was discussed, which provided a new basis for early clinical diagnosis and disease evaluation.

Methods

The clinical data of 130 patients with septic shock admitted to the IUC of our hospital from December 2021 to December 2023 were analyzed retrospectively. These subjects were divided into good prognosis group (n=78) and poor prognosis group (n=52) according to the 28 d deaths. The influencing factors were explored using the Multivariate logistic regression analysis. The value of single or combined PCT, PLT and TEG in predicting poor short-term prognosis was assessed using the receiver operating characteristic (ROC) curve.

Results

The patients in poor prognosis group had higher Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, serum PCT level, coagulation reaction time (R value) and coagulation formation time (K value), but lower PLT levels, final strength of coagulation (MA value) and coagulation formation rate (α angle) than those in good prognosis group (P<0.001). PCT, R value and K value were risk factors (P<0.001), while PLT, MA value and α angle were protective factors (P<0.001). The area under the curve (AUC) of PCT, PLT and TEG predicting poor short-term progression was 0.813, 0.658 and 0.752, respectively. The AUC of combined three indicators was 0.905, which had the highest predictive value.

Conclusion

Serum levels of PCT, PLT and TEG had certain value in predicting poor short-term progression of septic shock patients, and their combined diagnostic value was higher. Therefore, regular monitoring of these three indicators could provide certain guiding significance for the prevention and treatment of poor short-term prognosis in patients with septic shock.

A new prognostic model for recurrent pregnancy loss: assessment of thyroid and thromboelastograph parameters

Objective

This study aimed to identify predictors associated with thyroid function and thromboelastograph (TEG) examination parameters and establish a nomogram for predicting the risk of subsequent pregnancy loss in recurrent pregnancy loss (RPL).

Methods

In this retrospective study, we analyzed the medical records of 575 RPL patients treated at Lanzhou University Second Hospital, China, between September 2020 and December 2022, as a training cohort. We also included 272 RPL patients from Ruian People's Hospital between January 2020 and July 2022 as external validation cohort. Predictors included pre-pregnancy thyroid function and TEG examination parameters. The study outcome was pregnancy loss before 24 weeks of gestation. Variable selection was performed using least absolute shrinkage and selection operator regression and stepwise regression analyses, and the prediction model was developed using multivariable logistic regression. The study evaluated the model's performance using the area under the curve (AUC), calibration curve, and decision curve analysis. Additionally, dynamic and static nomograms were constructed to provide a visual representation of the models.

Results

The predictors used to develop the model were body mass index, previous pregnancy losses, triiodothyronine, free thyroxine, thyroid stimulating hormone, lysis at 30 minutes, and estimated percent lysis which were determined by the multivariable logistic regression with the minimum Akaike information criterion of 605.1. The model demonstrated good discrimination with an AUC of 0.767 (95%CI 0.725-0.808), and the Hosmer-Lemeshow test indicated good fitness of the predicting variables with a P value of 0.491. Identically, external validation confirmed that the model exhibited good performance with an AUC of 0.738. Moreover, the clinical decision curve showed a positive net benefit in the prediction model. Meanwhile, the web version we created was easy to use. The risk stratification indicated that high-risk patients with a risk score >147.9 had a higher chance of pregnancy loss (OR=6.05, 95%CI 4.09-8.97).

Conclusions

This nomogram well-predicted the risk of future pregnancy loss in RPL and can be used by clinicians to identify high-risk patients and provide a reference for pregnancy management of RPL.

Thromboelastometry for assessment of hemostasis and disease severity in 42 dogs with naturally-occurring heatstroke

BACKGROUND

Thromboelastometry (TEM) provides a comprehensive overview of the entire coagulation process and has not been evaluated in heatstroke-induced coagulopathies in dogs.

OBJECTIVES

To determine the diagnostic and prognostic utility of TEM in dogs with heatstroke.

ANIMALS

Forty-two client-owned dogs with heatstroke.

METHODS

Prospective observational study. Blood samples for intrinsic and extrinsic TEM (INTEM and EXTEM, respectively) were collected at presentation and every 12 to 24 hours for 48 hours. Coagulation phenotype (hypo-, normo-, or hypercoagulable) was defined based on TEM area under the 1st derivative curve (AUC).

RESULTS

Case fatality rate was 31%. Median TEM variables associated with death (P < .05 for all) included longer INTEM clotting time, lower AUC at presentation and at 12 to 24 hours postpresentation (PP), lower INTEM alpha angle, maximum clot firmness, and maximum lysis (ML) at 12 to 24 hours PP, and lower EXTEM ML at 12 to 24 hours PP. Most dogs were normo-coagulable on presentation (66% and 63% on EXTEM and INTEM, respectively), but hypo-coagulable 12 to 24 PP (63% for both EXTEM and INTEM). A hypo-coagulable INTEM phenotype was more frequent at presentation and 12 to 24 PP among nonsurvivors compared to survivors (55% vs 15% and 100% vs 50%, P = .045 and .026, respectively). AKI was more frequent (P = .015) in dogs with hypo-coagulable INTEM tracings at 12 to 24 hours. Disseminated intravascular coagulation was more frequent (P < .05) in dogs with a hypo-coagulable INTEM phenotype and in nonsurvivors at all timepoints.

CONCLUSIONS AND CLINICAL RELEVANCE

Hypocoagulability, based on INTEM AUC, is predictive of worse prognosis and occurrence of secondary complications.

Prognostic Role of Initial Thromboelastography in Emergency Department Patients with Primary Postpartum Hemorrhage: Association with Massive Transfusion

BACKGROUND

The early prediction of the need for massive transfusions (MTs) and the preparation of blood products are essential for managing patients with primary postpartum hemorrhage (PPH). Thromboelastography (TEG) enables a thorough evaluation of coagulation status and is useful for guiding the treatment of hemorrhagic events in various diseases. We investigated the role of TEG in predicting the need for MT in patients with primary PPH.

METHODS

A retrospective observational study was conducted in the emergency department (ED) of a university-affiliated, tertiary referral center between November 2015 and August 2023. TEG was performed upon admission. We defined MT as the requirement for transfusion of more than 10 units of packed red blood cells within the first 24 h. The primary outcome was the need for MT.

RESULTS

Among the 184 patients with initial TEG, 34 (18.5%) required MT. Except for lysis after 30 min, the MT and non-MT groups had significantly different TEG values. Based on multivariate analysis, an angle < 60 was an independent predictor of MT (odds ratio (OR) 7.769; 95% confidence interval (CI), 2.736-22.062), along with lactate (OR, 1.674; 95% CI, 1.218-2.300) and shock index > 0.9 (OR, 4.638; 95% CI, 1.784-12.056). Alpha angle < 60 degrees indicated the need for MT with 73.5% sensitivity, 72.0% specificity, and 92.3% negative predictive value.

CONCLUSIONS

Point-of-care testing of TEG has the potential to be a useful tool in accurately predicting the necessity for MT in ED patients with primary PPH at an early stage.

TEG-based transfusion protocol is associated with decreased blood product use without increased risk of hemoperitoneum

BACKGROUND

Thromboelastography (TEG) informs the need for blood product transfusions to prevent procedural bleeding complications in patients with cirrhosis. We aimed to evaluate the impact of using a TEG-based transfusion protocol on blood product utilization before paracentesis and the post-paracentesis hemoperitoneum (PPH) incidence.

METHODS

We conducted an ambispective analysis of patients with cirrhosis who underwent paracentesis from 2017 to 2021. In May 2019, we enacted a TEG-based transfusion protocol to guide pre-paracentesis blood product use. Patients with platelets < 20,000 or international normalized ratio ≥ 4 underwent TEG and received blood products if r value > 10 min or MA <30 mm. Patients were divided into pre-TEG and post-TEG protocol cohorts based on the date of paracentesis. Pre-paracentesis blood product transfusions in the form of platelets, fresh frozen plasma, and cryoprecipitates were recorded. PPH was defined as a decrease in hemoglobin of ≥1 g and the presence of blood on diagnostic imaging and/or the need for therapeutic intervention.

RESULTS

A total of 483 patients underwent 1281 paracenteses. The main etiologies of cirrhosis were alcohol (43%) and NASH (25%), and the mean MELD-sodium was 22±6. Pre-TEG and post-TEG protocol cohort sizes were similar: 253 patients and 607 paracenteses versus 230 patients and 674 paracenteses. After TEG-protocol implementation, blood product transfusions decreased significantly (228 vs. 49 products, p<0.001) with associated cost savings. One patient in each cohort developed PPH.

CONCLUSION

Implementation of a pre-paracentesis TEG-based transfusion protocol for patients with cirrhosis successfully resulted in decreased blood product use with no associated increase in incidence of PPH.

Analysis of related factors of portal vein thrombosis in liver cirrhosis

BACKGROUND AND AIMS

To investigate the usefulness of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), protein C (PC), and thromboelastography (TEG) to serve as a predictor of portal vein thrombosis (PVT) in patients with liver cirrhosis. Additionally, we examined the clinical significance of the above indicators in terms of disease progression.

METHODS

A total of 123 patients with liver cirrhosis were recruited from May 2021 to December 2021, according to the imaging findings. They were divided into the PVT group (n = 52) and the non-PVT group (n = 71). Furthermore, patients with PVT were divided into plasma transfusion groups (n = 13) and non-plasma transfusion groups (n = 39). The basic general information, past medical history, laboratory, and imaging examination data were collected and analyzed.

RESULTS

In univariate analysis, there was no significant difference between the two groups in IL-6, PC, reaction time (R), alpha angle (Angle), maximum amplitude, or coagulation index (CI) (P > 0.05). TNF-α in the PVT group was significantly lower than that in the non-PVT group (P = 0.001). K-time (K) in the PVT group was significantly higher than that in the non-PVT group (P = 0.031). There was no significant difference in IL-6, TNF-α, PC, or TEG between different Child-Pugh classification groups (P > 0.05). There were no significant differences in TEG between the plasma transfusion group and the non-plasma transfusion group. In Binary logistic regression analysis, TNF-α (OR = 0.9881, 95%CI = 0.971, 0.990, P < 0.001), K(OR = 1.28, 95% = 1.053, 1.569, P = 0.014), activate partial thromboplastin time (APTT) (OR = 0.753, 95%CI = 0.656, 0.865, P < 0.001), portal vein diameter (OR = 1.310, 95%CI = 1.108, 1.549, P = 0.002)and the history of splenectomy or embolism (OR = 7.565, 95%CI = 1.514, 37.799, P = 0.014)were related to the formation of PVT.

CONCLUSIONS

TNF-α, K, APTT, portal vein diameter, and splenectomy or embolism history were associated with PVT formation, but IL-6 was not.

Association between kaolin-induced maximum amplitude and slow-flow/no-reflow in ST elevation myocardial infarction patients treated with primary percutaneous coronary intervention

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) patients with a high thrombus burden have a relatively high slow-flow/no-reflow risk. However, the association between kaolin-induced maximum amplitude (MA_thrombin) and slow-flow/no-reflow has been scarcely explored.

METHODS

STEMI patients treated with primary percutaneous coronary intervention (PCI) were retrospectively enrolled from January 2015 to December 2019 at China-Japan Friendship Hospital. MA_thrombin levels were measured using thromboelastography before the PCI procedure. The patients were divided into two groups according to thrombolysis in myocardial infarction (TIMI) flow grade after primary PCI: the normal flow group (TIMI flow grade = 3) and slow-flow/no-reflow (TIMI flow grade ≤ 2). The logistic regression model and restricted cubic spline regression (RCS) were used to analyze the predictive value of MA_thrombin for slow-flow/no-reflow. All patients were followed up after discharge and observed the adverse cardiovascular events between the two groups.

RESULTS

A total of 690 patients were enrolled, with 108(15.7%) having slow-flow/no-reflow. The multivariate logistic regression model analysis showed that MA_thrombin level was an independent risk factor for slow-flow/no-reflow. The RCS analysis showed a nonlinear relationship between MA_thrombin levels and slow-flow/no-reflow. The cut-off value of MA_thrombin levels for predicting slow-flow/no-reflow was 68 mm. During a median follow-up time of 4.4 years, slow-flow/no-reflow (hazard ratio 1.93, 95% confidence interval 1.27-2.93, P = 0.002) and MA_thrombin levels (hazard ratio 1.06, 95% confidence interval 1.03-1.08, P < 0.001) were independent risk factors for predicting the long-term of adverse clinical cardiovascular events.

CONCLUSION

MA_thrombin was an independent risk factor for predicting slow-flow/ no-reflow in STEMI patients who underwent primary PCI.

Thromboelastography in guiding preventive platelet transfusion in patients with haematologic diseases

OBJECTIVE

This study analysed the relationships between the main thromboelastography (TEG) parameters, the platelet (PLT) count and clinical bleeding in patients with blood diseases. We explored the threshold of the relevant parameters in the pathological condition of bleeding, aiming to scientifically guide clinical prophylactic PLT transfusion.

METHODS

In total, 268 patients with clear diagnoses of blood diseases and thrombocytopenia were enrolled and divided into five groups, A, B, C, D and E, corresponding to PLT counts of 0-10 × 10⁹ /L, 11-20 × 10⁹ /L, 21-30 × 10⁹ /L, 31-50 × 10⁹ /L and 51-100 × 10⁹ /L, respectively. TEG and routine blood testing were performed simultaneously, the main TEG parameters and the PLT count were analysed, and the thresholds of the main TEG parameters in each group when the patient had bleeding were obtained.

RESULTS

The maximum amplitude (MA) in groups A, B and C increased gradually, with a significant difference between each pair of these groups (P < 0.05). In groups A, B, C, D and E, the corresponding MA at the time of bleeding was 43.5 mm, 39.6 mm, 38.0 mm, 35.2 mm and 50.5 mm, respectively, with statistically significant differences (P < 0.05).

CONCLUSIONS

The MA can be used as a reference indicator for preventive PLT transfusion to a certain extent. When the PLT count is within different ranges, the MA threshold for preventive PLT transfusion also differs. It is recommended that different PLT counts be correlated with different MA thresholds to guide clinical prophylactic PLT transfusion.

Which Septic Shock Patients With Non-Overt DIC Progress to DIC After Admission? Point-of-Care Thromboelastography Testing

BACKGROUND

Disseminated intravascular coagulation (DIC) is a life-threatening complication of septic shock; however, risk factors for its development after admission are unknown. Thromboelastography (TEG) can reflect coagulation disturbances in early non-overt DIC that are not detected by standard coagulation tests. This study investigated the risk factors including TEG findings as early predictors for DIC development after admission in septic shock patients with non-overt DIC.

METHODS

This retrospective observation study included 295 consecutive septic shock patients with non-overt DIC at admission between January 2016 and December 2019. DIC was defined as an International Society on Thrombosis and Hemostasis (ISTH) score ≥ 5. The primary outcome was non-overt DIC at admission that met the ISTH DIC criteria within 3 days after admission.

RESULTS

Of the 295 patients with non-overt DIC, 89 (30.2%) developed DIC after admission. The DIC group showed a higher ISTH score and 28-day mortality rate than the non-DIC group (2 vs. 3, P < 0.001; 13.6% vs. 27.0%, P = 0.008, respectively). The DIC rate increased with the ISTH score (7.7%, 13.3%, 15.8%, 36.5%, and 61.4% for scores of 0, 1, 2, 3, and 4, respectively). Among TEG values, the maximum amplitude (MA) was higher in the non-DIC group (P < 0.001). On multivariate analysis, an MA < 64 mm was independently associated with DIC development (odds ratio, 2.311; 95% confidence interval, 1.298-4.115).

CONCLUSIONS

DIC more often developed among those with admission ISTH scores ≥ 3 and was associated with higher mortality rates. An MA < 64 mm was independently associated with DIC development in septic shock patients.

Clinical Significance of Thrombelastography Results in Patients with Lung Adenocarcinoma in Situ Complicated with Type 2 Diabetes

To investigate the significance of thrombelastography (TEG) in patients who have lung adenocarcinoma in situ (LAIS) complicated with type 2 diabetes (T2D), 120 subjects were enrolled: 40 with LAIS, 40 with LAIS and T2D (LAIS + T2D), and 40 healthy controls (HCs). Correlation analysis was used to assess the relationships of TEG with indicators of T2D. The LAIS + T2D group had lower reaction time (R), rate of clot formation (K), estimated percentage of lysis (EPL), and lysis after 30 min (LY30), but higher maximum amplitude (MA), angle (α), and coagulation index (CI) than other group. Compared with the HC group, the LAIS group had lower R, K, EPL, and LY30, but higher MA, α, and CI. In LAIS + T2D group, R and LY30 had negatively correlations with fasting blood glucose (FBG) and triglycerides (TGs); α and MA had positive correlations with FBG and TG; K had negative correlations with FBG; EPL had negative correlations with FBG and low-density lipoprotein (LDL); and CI had positive correlations with FBG and LDL. TEG may be a useful indicator of blood coagulation dysfunction in these patients rather the healthy individuals.

Thromboelastography in elective total hip arthroplasty

BACKGROUND

Hypercoagulability plays an important role in predisposing patients to venous thromboembolism (VTE) after total hip arthroplasty (THA). We used thromboelastography (TEG) to examine the coagulation status of patients undergoing THA.

AIM

To examine coagulation as measured by TEG in patients undergoing THA who received standard VTE chemoprophylaxis with enoxaparin.

METHODS

After ethical approval, we performed a retrospective analysis of data collected in patients undergoing primary elective THA. We analyzed TEG data on samples performed before skin incision, intraoperatively and for 5 d postoperatively. Conventional coagulation tests were performed preoperatively and on postoperative day 5.

RESULTS

Twenty patients undergoing general anesthesia and 32 patients undergoing spinal anesthesia (SA) were included. TEG demonstrated a progressively hypercoagulable state postoperatively, characterized by elevated maximum amplitude. TEG also demonstrated transient intraoperative hypercoagulability in patients receiving SA. In contrast, conventional coagulation tests were normal in all patients, pre- and postoperatively, except for an increase in plasma fibrinogen day 5 postoperatively.

CONCLUSION

Despite VTE prophylaxis, patients following total hip replacement remain in a hypercoagulable state as measured by both TEG and conventional tests. This group may benefit from more optimal anticoagulation and/or additional perioperative hemostatic monitoring, via TEG or otherwise.

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.

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Correcting Coagulopathy With Fresh Frozen Plasma in the Surgical Intensive Care Unit: How Much Do We Need to Transfuse?

INTRODUCTION

Thromboelastography (TEG) is an assay that assesses the coagulation status. Patients with prolonged reaction time (R) require fresh frozen plasma (FFP); however, the volume required to correct the R time is unknown. We sought to quantify the volume required to correct the R time and calculate the response ratio in our surgical intensive care unit (SICU) to allow for targeted resuscitation.

METHODS

Surgical intensive care unit patients between Aug 2017 and July 2019 with a prolonged initial R time and at least two TEG tests performed within 24 hours were included. The response ratio was defined as the change in the R time divided by the number of FFP units. High responders (response ratio >5 minutes/unit) were compared to low responders (response ratio ≤5 minutes/unit).

RESULTS

Forty-six patients were included. While the mean response ratio was 5 minutes/unit, there was significant variation among patients. There were 28.0 (60.9%) low responders and 18.0 (39.1%) high responders. Low responders were more likely male (64.0% vs. 33.0%, P = .04), had a higher Acute Physiology and Chronic Health Evaluation (APACHE) IV score (42.0 vs. 27.0, P = .03), and a higher mortality rate (54.0% vs. 22.0%, P = .04).

CONCLUSIONS

On average, one unit of FFP corrects the R time by 5 minutes; however, there was significant variation between high and low responders. Male patients with higher APACHE IV score are expected to be low responders with a higher mortality rate. These findings can guide FFP transfusion and provide additional prognostication.

Thromboelastography (TEG) in normal pregnancy and its diagnostic efficacy in patients with gestational hypertension, gestational diabetes mellitus, or preeclampsia

BACKGROUND

Thromboelastography (TEG) provides global assessment of hemostatic function and has been recommended to monitor potential coagulopathies during pregnancy in which hypercoagulable state is favored. In present study, we established the reference intervals (RIs) of the TEG parameters (R, K, MA, and α-angle) with Chinese pregnant women of third trimester. In addition, we examined the diagnostic efficacies of the TEG parameters in the patients diagnosed of gestational hypertension (GH), gestational diabetes mellitus (GDM), or preeclampsia (PE).

METHODS

With specified including and excluding criteria, non-pregnant controls, healthy pregnant women, and pregnant women with GH, GDM, or PE had their venous blood drawn at Beijing Obstetrics and Gynecology Hospital, followed by TEG tests performed in the clinical laboratory.

RESULTS

The RIs determined with the healthy pregnant women (in third trimester) for R, K, MA, and α-angle were 4.0-7.7, 1.2-3.2, 51.9-70.1, and 41.4-74.4, respectively. When compared with the healthy pregnancy group, the K value was significantly decreased in GH patients but increased in PE patients; MA was significantly lower in the PE group. In the receiver operating characteristic curve (ROC) analyses, K value was able to efficiently distinguish normal pregnancy from the GH patients, with an AUC of 0.86 which is far better than those of R (AUC = 0.57) and MA (AUC = 0.56). For the PE patients, the AUC of MA (0.69) was significantly greater than that of R (0.50).

CONCLUSIONS

Thromboelastography may provide more accurate experimental basis for monitoring coagulation functions especially in pregnant women with complications of GH and PE.

Coagulative Disorders in Critically Ill COVID-19 Patients with Acute Distress Respiratory Syndrome: A Critical Review

In critically ill patients with acute respiratory distress syndrome (ARDS) coronavirus disease 2019 (COVID-19), a high incidence of thromboembolic and hemorrhagic events is reported. COVID-19 may lead to impairment of the coagulation cascade, with an imbalance in platelet function and the regulatory mechanisms of coagulation and fibrinolysis. Clinical manifestations vary from a rise in laboratory markers and subclinical microthrombi to thromboembolic events, bleeding, and disseminated intravascular coagulation. After an inflammatory trigger, the mechanism for activation of the coagulation cascade in COVID-19 is the tissue factor pathway, which causes endotoxin and tumor necrosis factor-mediated production of interleukins and platelet activation. The consequent massive infiltration of activated platelets may be responsible for inflammatory infiltrates in the endothelial space, as well as thrombocytopenia. The variety of clinical presentations of the coagulopathy confronts the clinician with the difficult questions of whether and how to provide optimal supportive care. In addition to coagulation tests, advanced laboratory tests such as protein C, protein S, antithrombin, tissue factor pathway inhibitors, D-dimers, activated factor Xa, and quantification of specific coagulation factors can be useful, as can thromboelastography or thromboelastometry. Treatment should be tailored, focusing on the estimated risk of bleeding and thrombosis. The aim of this review is to explore the pathophysiology and clinical evidence of coagulation disorders in severe ARDS-related COVID-19 patients.

Clinical Considerations of Coagulopathy in Acute Liver Failure

Acute liver failure (ALF) is the rapid onset of severe liver dysfunction, defined by the presence of hepatic encephalopathy and impaired synthetic function (international normalized ratio of ≥1.5) in the absence of underlying liver disease. The elevated international normalized ratio value in ALF is often misinterpreted as an increased hemorrhagic tendency, which can lead to inappropriate, prophylactic transfusions of blood products. However, global assessments of coagulopathy via viscoelastic tests or thrombin generation assay suggest a reestablished hemostatic, or even hypercoagulable, status in patients with ALF. Although the current versions of global assays are not perfect, they can provide more nuanced insights into the hemostatic system in ALF than the conventional measures of coagulopathy.

Features of Blood Clotting on Thromboelastography in Hospitalized Patients With Cirrhosis

INTRODUCTION

Thromboelastography (TEG) provides a global assessment of hemostasis and may have value for patients with cirrhosis who have multiple hemostatic defects. We sought to examine the characteristics of TEG in hospitalized patients with cirrhosis and its relationship with outcomes.

METHODS

We performed a cohort study of all adults with cirrhosis hospitalized at Indiana University Hospital between November 2015 and October 2018 with a TEG. We examined the relationships among TEG, traditional measures of hemostasis, liver disease severity, and outcomes, including mortality, discharge to hospice, length of stay, and 30-day readmission.

RESULTS

A total of 344 patients met inclusion and exclusion criteria. R-value was elevated (≥10 min) in 4.5%, alpha angle was low (<45°) in 9.3%, and maximum amplitude (maximum amplitude) was low (<55 mm) in 72.1%. K-value, alpha angle, and maximum amplitude were all correlated with both platelet count and fibrinogen (absolute rho range 0.52-0.67); R-value and international normalized ratio (INR) were not strongly correlated with traditional measures or TEG, respectively. Patients with bleeding had hypercoagulable profiles, and patients with infection had increased R-value and decreased alpha angle. A total of 35.8% died or were discharged to hospice, and these patients had a greater R-value and smaller alpha angle. However, after adjustment for model for end-stage liver disease (MELD), neither R-value nor alpha angle were associated with discharge outcomes.

CONCLUSIONS

TEG provides insight into the hemostatic state of patients with cirrhosis beyond that of standard measures of hemostasis. It is associated with liver disease severity and outcomes and may play a role complementary to standard measures of hemostasis in this population.

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.

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

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

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of pathological clotting using haematological, functional and morphological investigations in HIV-positive and HIV-negative patients with deep vein thrombosis

BACKGROUND

Patients infected with the human immunodeficiency virus (HIV) are more prone to systemic inflammation and pathological clotting, and many may develop deep vein thrombosis (DVT) as a result of this dysregulated inflammatory profile. Coagulation tests are not routinely performed unless there is a specific reason.

METHODS

We recruited ten healthy control subjects, 35 HIV negative patients with deep vein thrombosis (HIV negative-DVT), and 13 HIV patients with DVT (HIV positive-DVT) on the primary antiretroviral therapy (ARV) regimen-emtricitabine, tenofovir and efavirenz. Serum inflammatory markers, haematological results, viscoelastic properties using thromboelastography (TEG) and scanning electron microscopy (SEM) of whole blood (WB) were used to compare the groups.

RESULTS

The DVT patients (HIV positive and HIV negative) had raised inflammatory markers. The HIV positive-DVT group had anaemia in keeping with anaemia of chronic disorders. DVT patients had a hypercoagulable profile on the TEG but no significant difference between HIV negative-DVT and HIV positive-DVT groups. The TEG analysis compared well and supported our ultrastructural results. Scanning electron microscopy of DVT patient's red blood cells (RBCs) and platelets demonstrated inflammatory changes including abnormal cell shapes, irregular membranes and microparticle formation. All the ultrastructural changes were more prominent in the HIV positive-DVT patients.

CONCLUSIONS

Although there were trends that HIV-positive patients were more hypercoagulable on functional tests (viscoelastic profile) compared to HIV-negative patients, there were no significant differences between the 2 groups. The sample size was, however, small in number. Morphologically there were inflammatory changes in patients with DVT. These ultrastructural changes, specifically with regard to platelets, appear more pronounced in HIV-positive patients which may contribute to increased risk for hypercoagulability and deep vein thrombosis.

Platelet dysfunction during trauma involves diverse signaling pathways and an inhibitory activity in patient-derived plasma

BACKGROUND

Trauma-induced coagulopathy occurs in about 25% of injured patients and accounts for about 10% of deaths worldwide. Upon injury, hemostatic function may decline due to vascular dysfunction, clotting factor deficiencies, hyperfibrinolysis, and/or platelet dysfunction. We investigated agonist-induced calcium signaling in platelets obtained over time from trauma patients.

METHODS

Platelets from trauma patients and healthy donors were monitored via intracellular calcium mobilization and flow cytometry markers (α2bβ3 activation, P-selectin display, and phosphatidylserine exposure) following stimulation with a panel of agonists (adenosine 5'-diphosphate sodium salt, U46619, convulxin, PAR-1/4 activating peptides, iloprost) used in isolation or in pairwise tests. Furthermore, healthy donor platelets were tested in heterologous plasma isolated from healthy subjects and trauma patients.

RESULTS

When exposed to agonists over the first 24 hours postinjury, trauma patient platelets mobilized less calcium in comparison to healthy platelets. Partial recovery of platelet activity was observed in about a third of patients after 120 hours, although not fully obtaining healthy baseline function. Flow cytometry markers of trauma platelets were similar to healthy platelets prior to stimulation, but were depressed in trauma platelets stimulated with adenosine 5'-diphosphate sodium salt or convulxin. Also, washed healthy platelets showed a significant reduction in calcium mobilization when reconstituted in plasma from trauma patients, relative to healthy plasma, at all plasma doses tested.

CONCLUSION

Platelet dysfunction in trauma patients included poor response to multiple agonists relevant to hemostatic function. Furthermore, the inhibitor effect of patient plasma on healthy platelets suggests that soluble plasma species may downregulate endogenous or transfused platelets during trauma.

Thromboelastography in pre-surgery monitoring in Hemophilia A with high inhibitor titer: case report and literature review

The development of factor VIII inhibitors (allo-antibodies) continues to be a major complication in the management of severe forms of hemophilia A, especially as far as treatment and treatment response monitoring is concerned. The need to implement a reliable laboratory assay is all the more obvious if major surgery occurs, when conventional tests (activated partial thromboplastin time APTT, prothrombin time PT, factor VIII level) are of no avail and there is a very fragile balance between bleeding and thrombosis.

We report the case of a 32 year-old patient diagnosed with severe Hemophilia A, referred to the Comprehensive Center for the Diagnosis and Treatment of Hemophilia of the Fundeni Clinical Institute for a multidisciplinary assessment in view of a total left hip arthroplasty due to aseptic necrosis of the femoral neck.

Workup showed a high inhibitor titer (>200 BU). Taking into consideration the interindividual variability of the response to bypassing agents, as well as the bleeding risk associated with a major orthopedic surgery, we used thromboelastography (TEG) to assess the patient’s response to aPCC (activated prothrombin complex concentrate) and rFVIIa (activated recombinant factor VII). The findings helped select the optimal replacement scheme to ensure perioperative hemostasis.

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

GOALS

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

BACKGROUND

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

STUDY

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

RESULTS

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

CONCLUSIONS

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

Thrombin Generation in Chinese Pregnant Women and the Effect of Insulin Use on Thrombin Generation in Patients with GDM

Pregnancy is a hypercoagulable state associated with an increased risk of venous thrombosis. Calibrated automated thrombogram (CAT) is a test to monitor the thrombin generation (TG), a laboratory marker of thrombosis risk, and increases during normal pregnancy, but it is still unclear whether TG is related to the use of insulin in pregnant women with gestational diabetes mellitus (GDM). We performed thrombin generation by CAT on 135 normal pregnant women, including 43 in first trimester, 32 in second trimester, 60 in third trimester, respectively; 68 pregnant women with GDM were also enrolled, 19 patients with GDM using insulin to control blood glucose and 49 patients control their blood glucose through diet and exercise with noninsulin treatment. The overall CAT parameters were calculated using descriptive statistics method with mean ± standard deviation. Mean endogenous thrombin potential, peak thrombin generation, and StartTail time increased significantly with the pregnancy. There was no significant difference in TG test parameters except StartTail time(P = .003) in insulin-treated GDM group when compared to those without insulin in the GDM group. The normal ranges for CAT parameters in pregnant women were determined. Thrombin generation increased significantly in first trimester and remains stable in second and third trimester. The use of insulin in patient with GDM did not affect thrombin generation test. Our study helps to establish the reference range of thrombin generation in Chinese normal pregnant population and provide more basis to predict the risk of thrombus complicating during pregnancy.

Targeting thrombogenicity and inflammation in chronic HIV infection

Persons with HIV infection (PWH) have increased risk for cardiovascular disease (CVD), but the underlying mechanisms remain unclear. Coronary thrombosis is known to provoke myocardial infarctions, but whether PWH have elevated thrombotic propensity is unknown. We compared thrombogenicity of PWH on antiretroviral therapy versus matched controls using the Badimon chamber. Measures of inflammation, platelet reactivity, and innate immune activation were simultaneously performed. Enrolled PWH were then randomized to placebo, aspirin (81 mg), or clopidogrel (75 mg) for 24 weeks to assess treatment effects on study parameters. Thrombogenicity was significantly higher in PWH and correlated strongly with plasma levels of D-dimer, soluble TNF receptors 1 and 2, and circulating classical and nonclassical monocytes in PWH. Clopidogrel significantly reduced thrombogenicity and sCD14. Our data suggest that higher thrombogenicity, interacting with inflammatory and immune activation markers, contributes to the increased CVD risk observed in PWH. Clopidogrel exhibits an anti-inflammatory activity in addition to its antithrombotic effect in PWH.

Multiple electrode aggregometry and thromboelastography in thrombocytopenic patients with haematological malignancies

BACKGROUND

In thrombocytopenic patients better assessment of bleeding risk than that provided by platelet count alone is required. Multiplate® aggregometry and thromboelastography (TEG) could be used, but information on their role in such patients is limited. The primary aim of this study was to investigate the feasibility of Multiplate® analyses in patients with haematological malignancies. A secondary aim was to explore whether a multiple logistic regression model combining Multiplate®, TEG, clinical and laboratory variables was associated with risk of bleeding.

MATERIALS AND METHODS

This was an exploratory, prospective observational study of thrombocytopenic patients with haematological malignancies. Total platelet count (TPC), white blood cell count, C-reactive protein (CRP) level, temperature and bleeding status were recorded daily. TEG and Multiplate® analyses with four agonists were performed on weekdays.

RESULTS

Ten patients were enrolled into the study. The median number of days in a study period was 21. Bleeding was observed on 64 of 298 study days. TPC <20×109/L and <10×109/L occurred on 119 and 25 days, respectively. When TPC was <33×109/L, many samples showed no aggregation, regardless of bleeding status. Despite this, the odds of World Health Organization (WHO) grade 2 bleeding decreased significantly as aggregation increased and Multiplate® had a negative predictive value (NPV) of 96% and a positive predictive value (PPV) of 19% for significant bleeding. In the multiple logistic regression model collagen-activated Multiplate® aggregation, TEG angle, TEG reaction time and CRP significantly affected the odds of WHO grade 2 bleeding. The combined model had a NPV of 99% and a PPV of 19%.

DISCUSSION

Our findings suggest that the markers of platelet function and haemostasis provided by Multiplate® aggregometry and TEG may add information to support prediction of bleeding, although platelet count still remains the most accessible analysis for routine testing.

Analysis of thrombelastogram-guided medication in patients with coronary heart disease after percutaneous coronary intervention

Effects of thrombelastogram-guided (TEG-guided) clopidogrel and aspirin on major adverse cardiovascular events (MACE) after percutaneous coronary intervention (PCI) were investigated. A retrospective analysis was performed on 203 patients undergoing PCI interventional therapy in the Cardiovascular Medicine of Weihai Central Hospital from February 2015 to September 2016. The patients were treated with clopidogrel and aspirin for anti-thrombus therapy. Among them, 104 patients who had TEG detection of anticoagulant effects for guiding medication were the experimental group, and 99 patients without TEG detection for guiding medication the control group. The coagulation function and the platelet inhibition rate of patients after medication were evaluated and compared between the two groups. The incidence of MACE and bleeding events of patients was counted during three months of follow-up. Patients in the experimental group had higher R (coagulation reaction time) value and K (blood clot formation time) value than those in the control group after treatment (P<0.05), and lower MA (maximum amplitude) value than those in the control group (P<0.05). Patients in the experimental group had higher postoperative platelet inhibition rate than those in the control group (P<0.05). Patients in the experimental group had lower incidence of MACE and bleeding events than those in the control group (P<0.05). Coronary heart disease (CHD) patients after PCI with the TEG-guided dose adjustment of clopidogrel have more satisfactory treatment effects than patients without the TEG guidance. TEG makes the treatment of patients more targeted and is worthy of promotion.

TEG in the monitoring of coagulation changes in patients with sepsis and the clinical significance

Application values of thromboelastography (TEG) in dynamic monitoring of coagulation parameters of sepsis patients were investigated. Eighty-one patients with sepsis who were admitted to the ICU department of the General Hospital of Ningxia Medical University from April 1, 2015 to December 31, 2015 were collected. Clinical data of the patients were collected. Data were compared using 5 grouping methods: i) the 81 patients were divided into the sepsis group (n=45) and sepsis shock group (n=36); ii) patients were divided into two groups: group A (APACHE II score ≤13, n=51); group B (APACHE II score >13, n=30); iii) according to Disseminated Intravascular Coagulation Diagnosis Integral System (CDSS), patients were divided into non-disseminated intravascular coagulation (DIC) group (CDSS <7 points) and DIC group (CDSS ≥7 points); TEG indexes were compared between the two groups; iv) correlation between TEG indexes and Sequential Organ Failure Assessment (SOFA) scores was analyzed; v) patients were divided into survival group and non-survival group and correlations between TEG indicators and prognosis were analyzed. At 6 h after ICU entry, compared with sepsis group, R value and K time were significantly increased, LY30 was also increased, while MA value, coagulation index (CI), and α angle were significantly decreased in the septic shock group (P<0.05). At 6 h after ICU entry, compared with sepsis group, R value and K time were significantly increased, while MA value, CI, and α angle were significantly decreased in the septic shock group (P<0.05). Compared with the non-DIC group, the DIC group had prolonged K time, decreased α angle, increased R value, and decreased CI and MA value (P<0.05). With increase of SOFA scores, R value and K value increased significantly, and α angle, MA value, and CI decreased significantly (P<0.05). According to TEG, platelet function and fibrinogen function of DIC patients were significantly reduced, and the body showed hypocoagulability.

Evaluation of EC50 of factor VIII as predictor of prophylaxis efficacy in patients with severe haemophilia A

Trough factor (F) VIII level is a not reliable bleeding risk indicator to predict prophylaxis efficacy in severe haemophilia A (SHA), therefore, accurate biomarkers are much needed. Thrombelastography (TEG) monitors both thrombin and clot formation addressing the global haemostatic status but its usefulness to tailor prophylaxis in haemophilia has been poorly evaluated. In this study, correspondence between individual pharmacodynamic/pharmacokinetic profile of FVIII and joint condition, physical activity and bleeding phenotype of SHA patients under prophylactic treatment was assessed. Nineteen SHA patients < 18 years old on long-term prophylaxis treatment with FVIII were studied in an observational cross-sectional study. Whole blood was withdrawn before FVIII administration and at five time-points after infusion for a TEG-based pharmacodynamic- and pharmacokinetic-study. Type of prophylaxis and joint condition at inclusion and physical activity as well as onset of treated spontaneous bleeding events in the previous two years were retrospectively assessed. Six patients had suffered at least one treated spontaneous bleeding event and were named as "bleeders". The rest were named as "non-bleeders". Only the half maximal effective concentration of FVIII (FVIII-EC50) for TEG parameters R-time, K-time and α-angle correlated with the bleeding phenotype being significantly higher in bleeders suggestive of a poorer response to FVIII. Poorer joint condition, trough FVIII levels or type of prophylaxis were not definitive predicting variables of bleeding phenotype. In conclusion, this study reveals FVIII-EC50 for the first time as a valuable biomarker to anticipate individual efficacy of prophylaxis in SHA.

Closing the gap - detection of clinically relevant von Willebrand disease in emergency settings through an improved algorithm based on rotational Thromboelastometry

Background

Hemorrhage and blood loss are still among the main causes of preventable death. Global hemostatic assays are useful point-of-care test (POCT) devices to rapidly detect cumulative effects of plasma factors and platelets on coagulation. Thromboelastography (TEG) and Thromboelastometry (ROTEM) are established methods in many anesthesiological departments for guided hemostatic treatment. However, von Willebrand disease remains undetected by standard ROTEM, especially during emergency care, despite being the most prevalent congenital hemostatic disorder.

Methods

In our monocentric cohort pilot study we focused on hemostatic challenges associated with von Willebrand disease. Twenty-seven patients with suspected von Willebrand disease were included. We modified the routine ROTEM assay by adding a preincubation with ristocetin and commercially available plasma-derived von Willebrand factor to identify clinically relevant von Willebrand disease (VWD).

Results

Addition of von Willebrand factor to the ristocetin assay of a VWD type 3 patient restored the reaction of the whole blood probe to match the response of a healthy person. Our modified ROTEM assay with ristocetin (Ricotem) showed that all high responders (n = 7) had VWD. In the low responder group (n = 16) – 10 of 16 had VWD and in the normal responder group (n = 5), 2 of 5 had mild type 1 VWD.

Conclusions

This new modification of the standard ROTEM assay enables the detection of otherwise unnoticed critical von Willebrand disease based on alterations in clot formation and might serve as a novel approach to reliably assess severe VWD patients by platelet-mediated blood clotting in an emergency setting. We recommend incorporating this new VWD-focused screening tool into the current ROTEM-based management algorithm of acute microvascular bleeding.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0672-8) contains supplementary material, which is available to authorized users.

TEG Platelet Mapping and Impedance Aggregometry to Predict Platelet Transfusion During Cardiopulmonary Bypass in Pediatric Patients

Background: Cardiopulmonary bypass-related platelet dysfunction can increase the risk of intra- and post-operative bleeding in children undergoing cardiac surgery. More accurate laboratory tests that identify acquired platelet abnormalities could allow for rapid identification of patients at risk of bleeding and provide therapies that could reduce bleeding and platelet transfusions. We hypothesized that thromboelastography with platelet mapping (TEG-PM) and multiple electrode impedance aggregometry (MEIA) as functional measures of platelet function would predict who will require platelet transfusion. Our secondary hypothesis was that platelet aggregation at both arachidonic acid (AA) and adenosine diphosphate (ADP) receptors would correlate between TEG-PM and MEIA results. Methods: In this prospective study from August 2013 to December 2015, children from newborn to 5 years of age with congenital heart disease undergoing cardiopulmonary bypass had blood samples collected and analyzed at four time points: pre-bypass, post-bypass, post-operatively on arrival to the Cardiac Intensive Care Unit, and 24 h after arrival. Results: Of the 44 patients analyzed, the 10 patients who received peri-operative platelet transfusion were significantly younger (p = 0.05), had higher STAT (Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery) Mortality Categories (p < 0.002) and longer cardiopulmonary bypass times (p = 0.02). In univariate analysis, four variables were associated with peri-operative platelet transfusion: pre-operative age [OR 0.95 (0.93, 0.98), p = 0.03], cardiopulmonary bypass time [1.5 (1.31, 1.68), p = 0.008], STAT Mortality Category [3.64 (3.40, 3.87), p < 0.001], and TEG-PM ADP [0.79 (0.65, 0.93), p = 0.04]. ROC analysis demonstrated moderate predictive value of TEG-PM ADP with AUC of 0.745 (0.59, 0.91). A TEG-PM ADP value of less than or equal to 21 had 85% sensitivity and 70% specificity for platelet transfusion. In the multivariate analysis, only STAT Mortality Category predicted platelet transfusion. TEG-PM and MEIA results correlated for the AA receptor at all 4 time points, but the same tests at the ADP receptors did not correlate. Conclusions: TEG-PM ADP may provide more clinically relevant information regarding platelet function compared to the MEIA at the ADP receptor in children requiring cardiopulmonary bypass. There was limited correlation between TEG-PM and MEIA results which raises a concern about the accuracy of these tests at the ADP receptor. Lower pre-operative TEG-PM ADP MA may predict intra-operative platelet transfusions; however, larger studies are needed to determine the utility of TEG-PM and MEIA in guiding platelet transfusions in this population.

Evaluation of coagulation disorders by thromboelastography in children with systemic lupus erythematosus

Background

The coagulation status of patients with systemic lupus erythematosus (SLE) is quite complicated, and there are currently no simple efficient methods for its evaluation. We explored the feasibility of thromboelastography (TEG) for this purpose.

Methods

Paediatric SLE patients were divided into different groups based on Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores. TEG parameters were compared between patients and healthy controls (HCs) and in patients by level of disease activity. Six patients treated with pulse methylprednisolone were also analysed before and after treatment.

Results

Thirty-nine children with SLE were enrolled, one of whom had bleeding and three of whom had thrombosis. The four TEG tracings of these four children were different. The TEG parameters of the patients (except the four children mentioned above) showed hypercoagulability, shortened R and K times, increased α-angle and maximum amplitude (MA), decreased LY30 and increased clot index (CI) compared with the parameters of the HCs ( P < 0.05). With respect to disease activity, patients with higher SLEDAI scores showed more obvious hypercoagulability with shortened R and K times and increased α-angle and CI ( P < 0.05). Furthermore, there was a negative correlation between both the R time and K time and SLEDAI scores ( r = –0.435, P < 0.01 and r  =  –0.572, P  < 0.001, respectively) and a positive correlation between both α-angle and CI and SLEDAI scores ( r = 0.581, P  < 0.001 and r  =  0.544, P  < 0.01, respectively). No significant difference in coagulation status was found between pre- and post-pulse therapy.

Conclusions

Compared with the HCs, paediatric SLE patients showed hypercoagulability caused by increased coagulation and decreased fibrinolysis. These coagulation changes were associated with disease activity. TEG could be a potential tool for evaluating the coagulation status of children with SLE.

Management of bleeding in major burn surgery

Major burn surgery is often associated with excessive bleeding and massive transfusion, and the development of a coagulopathy during major burn surgery is associated with increased morbidity and mortality. The aim of this study was to review the literature on intraoperative haemostatic resuscitation of burn patients during necrectomy to reveal strategies applied for haemostatic monitoring and resuscitation. We searched PubMed, EMBASE, and CENTRAL for studies published in the period 2006-2017 concerning bleeding issues related to burn surgery i.e. coagulopathy, transfusion requirements and clinical outcomes. In a broad search, a total of 1375 papers were identified. 124 of these fulfilled the inclusion criteria, and six of these were included for review. The literature confirmed that transfusion requirements increases with burn injury severity and that haemostatic monitoring by TEG^® (thrombelastography) or ROTEM^® (rotational thromboelastometry) significantly decreased intraoperative transfusions and was useful in predicting and goal-directing haemostatic therapy during excision surgery. Resuscitation of bleeding during major burn surgery in many instances was neither standardized nor haemostatic. We suggest that resuscitation should aim for normal haemostasis during the bleeding phase through close haemostatic monitoring and resuscitation. Randomised controlled trials are highly warranted to confirm the benefit of this concept.

Combination of aptamer and drug for reversible anticoagulation in cardiopulmonary bypass

Unfractionated heparin (UFH), the standard anticoagulant for cardiopulmonary bypass (CPB) surgery, carries a risk of post-operative bleeding and is potentially harmful in patients with heparin-induced thrombocytopenia-associated antibodies. To improve the activity of an alternative anticoagulant, the RNA aptamer 11F7t, we solved X-ray crystal structures of the aptamer bound to factor Xa (FXa). The finding that 11F7t did not bind the catalytic site suggested that it could complement small-molecule FXa inhibitors. We demonstrate that combinations of 11F7t and catalytic-site FXa inhibitors enhance anticoagulation in purified reaction mixtures and plasma. Aptamer-drug combinations prevented clot formation as effectively as UFH in human blood circulated in an extracorporeal oxygenator circuit that mimicked CPB, while avoiding side effects of UFH. An antidote could promptly neutralize the anticoagulant effects of both FXa inhibitors. Our results suggest that drugs and aptamers with shared targets can be combined to exert more specific and potent effects than either agent alone.

Platelet and coagulation disorders in newly diagnosed patients with pulmonary arterial hypertension

There is a complex and not fully elucidated association between pulmonary arterial hypertension (PAH) and coagulation disorders. The goal of this study was to evaluate platelet function, coagulation and fibrinolysis in PAH patients at diagnosis, before PAH-specific treatment initiation. We enrolled 20 healthy controls and 30 PAH patients (20 with connective tissue disease (CTD-PAH) and 10 idiopathic (iPAH)). None of the participants was on any antiplatelet or anticoagulation therapy. Blood samples from PAH patients were collected during the initial right heart catheterization. All subjects were assessed with platelet function analyzer-100 (PFA-100), epinephrine (Epi) and ADP-induced light transmission aggregometry (LTA), thromboelastometry (ROTEM) and endogenous thrombin potential (ETP). Our results showed that Epi and ADP-LTA values were significantly lower in newly diagnosed PAH patients compared to controls. Disaggregation was present in 73% of patients, a characteristic not seen in healthy individuals. In ROTEM assay, CT and CFT measurements were significantly higher and a angle lower compared to controls. ETP testing revealed significantly reduced outcomes in AUC, Cmax and Tmax. When CTD-PAH and iPAH patient groups were compared, iPAH ADP-LTA values were significantly decreased compared to CTD-PAH. In conclusion, newly diagnosed PAH patients presented with decreased platelet aggregation, clot propagation and thrombin generation, along with delayed initiation of the coagulation process. These hemostatic deficits could indicate an "exhaustion" of the coagulation process that could be caused by endothelial dysfunction and chronic activation of the procoagulant pathways. Further studies are warranted to confirm these laboratory findings and assess their potential clinical significance.

Thrombelastography Suggests Hypercoagulability in Patients with Renal Dysfunction and Intracerebral Hemorrhage

BACKGROUND

The objective of this study was to quantify coagulopathy using thrombelastography (TEG) in patients with renal dysfunction and intracerebral hemorrhage (ICH).

METHODS

We reviewed patients admitted with spontaneous ICH between November 2009 and May 2015. TEG was performed at the time of admission. Creatinine clearance (CCr) was calculated using the Cockroft-Gault equation. Patients were divided into 2 groups based on normal (CCr ≥ 90) or reduced renal function (CCr < 90). Multivariable regression models were conducted to compare the differences of TEG components.

RESULTS

A total of 120 patients were included in the analysis. The normal CCr group was younger (56.1 versus 62.3 years, P < .01), was more often male (73.6% versus 53.7%, P = .03), and had higher mean admission hemoglobin (14.2 versus 13.2 mEq/L, P < .01) than the reduced renal function group. The 2 groups were similar with respect to antiplatelet or anticoagulant use, coagulation studies, and baseline ICH volume. Following multivariate analysis, the reduced renal function group was found to have shorter K (1.5 versus 2.2 min, P = 004), increased angle (66 versus 62.2 degrees, P = .04), increased MA (67.3 versus 62.3, P = .02), and increased G (11.3 versus 9.9 dynes/cm², P = .04) compared with the normal group. Mortality, poor functional outcome (modified Rankin Scale score 4-6), hematoma enlargement, hospital length of stay, and surgical interventions were not different between the 2 groups.

CONCLUSIONS

Patients with ICH and reduced CCr display faster clotting rate and increased clot strength, suggesting that patients with renal dysfunction present with a relatively hypercoagulable state based on TEG parameters thought to reflect platelet activity.