The effect of Mycobacterium tuberculosis treatment on thrombelastography-assessed haemostasis: a prospective cohort study.

BACKGROUND AND OBJECTIVE: Tuberculosis disease (TB) and tuberculosis infection (TBI) have been associated with increased risk of cardiovascular disease which may be connected to infection-related haemostatic changes. It is unknown if treatment of Mycobacterium tuberculosis influences haemostasis. Here, we assessed if TB or TBI treatment affects thrombelastography (TEG)-assessed haemostasis. METHODS: Individuals with TB or TBI were included from a TB outpatient clinic in Copenhagen, Denmark. Patients treated with antithrombotic medication or systemic immunosuppressants were excluded. TEG analysis was performed before and after TB/TBI treatment using the TEG®6s analyser to provide data on the reaction time of clot initiation (R) (min), the speed of clot formation (K) (min) and clot build-up (Angle) (°), maximum clot strength (MA) (mm), and clot breakdown/fibrinolysis (LY30) (%). Differences in TEG were assessed using paired t tests. RESULTS: We included eleven individuals with TB with median [interquartile range] [IQR] age 52 (Liu et al. in Medicine (United States) 95, 2016) years and mean (standard deviation) (SD) body mass index (BMI) 24.7 (6.3) kg/m2 as well as 15 individuals with TBI with median [IQR] age 49 (Wells et al. in Am J Respir Crit Care Med 204:583, 2021) years and BMI 26.0 (3.2) kg/m2. Treatment reduced MA for both TB (64.0 (6.3) vs. 57.9 (5.2) mm, p = 0.016) and TBI (61.3 (4.1) vs. 58.6 (5.0) mm, p = 0.023) whereas R, K, Angle and LY30 were unaffected. CONCLUSION: TEG analysis showed that treatments of TB and TBI were associated with reduced MA which may indicate the existence of cardiovascular benefits from therapy. TRIAL REGISTRATION: Registered at ClinicalTrials.gov 05 April 2021 with registration number NCT04830462.

Thrombelastography and Conventional Coagulation Markers in Chronic Obstructive Pulmonary Disease: A Prospective Paired-Measurements Study Comparing Exacerbation and Stable Phases.

Chronic Obstructive Pulmonary Disease (COPD) exacerbation is known for its substantial impact on morbidity and mortality among affected patients, creating a significant healthcare burden worldwide. Coagulation abnormalities have emerged as potential contributors to exacerbation pathogenesis, raising concerns about increased thrombotic events during exacerbation. The aim of this study was to explore the differences in thrombelastography (TEG) parameters and coagulation markers in COPD patients during admission with exacerbation and at a follow-up after discharge. This was a multi-center cohort study. COPD patients were enrolled within 72 h of hospitalization. The baseline assessments were Kaolin-TEG and blood samples. Statistical analysis involved using descriptive statistics; the main analysis was a paired t-test comparing coagulation parameters between exacerbation and follow-up. One hundred patients participated, 66% of whom were female, with a median age of 78.5 years and comorbidities including atrial fibrillation (18%) and essential arterial hypertension (45%), and sixty-five individuals completed a follow-up after discharge. No significant variations were observed in Kaolin-TEG or conventional coagulation markers between exacerbation and follow-up. The Activated Partial Thromboplastin Clotting Time (APTT) results were near-significant, with p = 0.08. In conclusion, TEG parameters displayed no significant alterations between exacerbation and follow-up.

Ruthenium Antivenom Inhibits the Defibrinogenating Activity of Crotalus adamanteus Venom in Rabbits.

Eastern Diamondback Rattlesnake (Crotalus adamanteus) envenomation is a medical emergency encountered in the Southeastern United States. The venom contains a snake venom thrombin-like enzyme (SVTLE) that is defibrinogenating, causing coagulopathy without effects on platelets in humans. This investigation utilized thrombelastographic methods to document this coagulopathy kinetically on the molecular level in a rabbit model of envenomation via the analyses of whole blood samples without and with platelet inhibition. Subsequently, the administration of a novel ruthenium compound containing site-directed antivenom abrogated the coagulopathic effects of envenomation in whole blood without platelet inhibition and significantly diminished loss of coagulation in platelet-inhibited samples. This investigation provides coagulation kinetic insights into the molecular interactions and results of SVTLE on fibrinogen-dependent coagulation and confirmation of the efficacy of a ruthenium antivenom. These results serve as a rationale to investigate the coagulopathic effects of other venoms with this model and assess the efficacy of this site-directed antivenom.

Phosphate-Buffered Saline and Dimethyl Sulfoxide Enhance the Antivenom Action of Ruthenium Chloride against Crotalus atrox Venom in Human Plasma-A Preliminary Report.

Ruthenium chloride (RuCl3) is widely utilized for synthesis and catalysis of numerous compounds in academia and industry and is utilized as a key molecule in a variety of compounds with medical applications. Interestingly, RuCl3 has been demonstrated to modulate human plasmatic coagulation and serves as a constituent of a compounded inorganic antivenom that neutralizes the coagulopathic effects of snake venom in vitro and in vivo. Using thrombelastography, this investigation sought to determine if RuCl3 inhibition of the fibrinogenolytic effects of Crotalus atrox venom could be modulated by vehicle composition in human plasma. Venom was exposed to RuCl3 in 0.9% NaCl, phosphate-buffered saline (PBS), or 0.9% NaCl containing 1% dimethyl sulfoxide (DMSO). RuCl3 inhibited venom-mediated delay in the onset of thrombus formation, decreased clot growth velocity, and decreased clot strength. PBS and DMSO enhanced the effects of RuCl3. It is concluded that while a Ru-based cation is responsible for significant inhibition of venom activity, a combination of Ru-based ions containing phosphate and DMSO enhances RuCl3-mediated venom inhibition. Additional investigation is indicated to determine what specific Ru-containing molecules cause venom inhibition and what other combinations of inorganic/organic compounds may enhance the antivenom effects of RuCl3.

Coagulation Management of Critically Bleeding Patients With Viscoelastic Testing Presented as a 3D-Animated Blood Clot (The Visual Clot): Randomized Controlled High-Fidelity Simulation Study.

BACKGROUND: Guidelines recommend using viscoelastic coagulation tests to guide coagulation management, but interpreting the results remains challenging. Visual Clot, a 3D animated blood clot, facilitates interpretation through a user-centered and situation awareness-oriented design. OBJECTIVE: This study aims to compare the effects of Visual Clot versus conventional viscoelastic test results (rotational thrombelastometry [ROTEM] temograms) on the coagulation management performance of anesthesia teams in critical bleeding situations. METHODS: We conducted a prospective, randomized, high-fidelity simulation study in which anesthesia teams (consisting of a senior anesthesiologist, a resident anesthesiologist, and an anesthesia nurse) managed perioperative bleeding scenarios. Teams had either Visual Clot or ROTEM temograms available to perform targeted coagulation management. We analyzed the 15-minute simulations with post hoc video analysis. The primary outcome was correct targeted coagulation therapy. Secondary outcomes were time to targeted coagulation therapy, confidence, and workload. In addition, we have conducted a qualitative survey on user acceptance of Visual Clot. We used Poisson regression, Cox regression, and mixed logistic regression models, adjusted for various potential confounders, to analyze the data. RESULTS: We analyzed 59 simulations. Teams using Visual Clot were more likely to deliver the overall targeted coagulation therapy correctly (rate ratio 1.56, 95% CI 1.00-2.47; P=.05) and administer the first targeted coagulation product faster (hazard ratio 2.58, 95% CI 1.37-4.85; P=.003). In addition, participants showed higher decision confidence with Visual Clot (odds ratio 3.60, 95% CI 1.49-8.71; P=.005). We found no difference in workload (coefficient -0.03, 95% CI -3.08 to 2.88; P=.99). CONCLUSIONS: Using Visual Clot led to a more accurate and faster-targeted coagulation therapy than using ROTEM temograms. We suggest that relevant viscoelastic test manufacturers consider augmenting their complex result presentation with intuitive, easy-to-understand visualization to ease users' burden from unnecessary cognitive load and enhance patient care.

Novel Toxicodynamic Model of Subcutaneous Envenomation to Characterize Snake Venom Coagulopathies and Assess the Efficacy of Site-Directed Inorganic Antivenoms.

Venomous snake bite adversely affects millions of people yearly, but few animal models allow for the determination of toxicodynamic timelines with hemotoxic venoms to characterize the onset and severity of coagulopathy or assess novel, site-directed antivenom strategies. Thus, the goals of this investigation were to create a rabbit model of subcutaneous envenomation to assess venom toxicodynamics and efficacy of ruthenium-based antivenom administration. New Zealand White rabbits were sedated with midazolam via the ear vein and had viscoelastic measurements of whole blood and/or plasmatic coagulation kinetics obtained from ear artery samples. Venoms derived from Crotalus scutulatus scutulatus, Bothrops moojeni, or Calloselasma rhodostoma were injected subcutaneously, and changes in coagulation were determined over three hours and compared to samples obtained prior to envenomation. Other rabbits had ruthenium-based antivenoms injected five minutes after venom injection. Viscoelastic analyses demonstrated diverse toxicodynamic patterns of coagulopathy consistent with the molecular composition of the proteomes of the venoms tested. The antivenoms tested attenuated venom-mediated coagulopathy. A novel rabbit model can be used to characterize the onset and severity of envenomation by diverse proteomes and to assess site-directed antivenoms. Future investigation is planned involving other medically important venoms and antivenom development.

The Gilded Clot: Review of Metal-Modulated Platelet Activation, Coagulation, and Fibrinolysis.

The processes of blood coagulation and fibrinolysis that in part maintain the physical integrity of the circulatory system and fluidity of its contents are complex as they are critical for life. While the roles played by cellular components and circulating proteins in coagulation and fibrinolysis are widely acknowledged, the impact of metals on these processes is at best underappreciated. In this narrative review we identify twenty-five metals that can modulate the activity of platelets, plasmatic coagulation, and fibrinolysis as determined by in vitro and in vivo investigations involving several species besides human beings. When possible, the molecular interactions of the various metals with key cells and proteins of the hemostatic system were identified and displayed in detail. It is our intention that this work serve not as an ending point, but rather as a fair evaluation of what mechanisms concerning metal interactions with the hemostatic system have been elucidated, and as a beacon to guide future investigation.

Factors influencing thrombelastography in pregnancy. / å¦Šå¨ æœŸè¡€æ “å¼¹åŠ›å›¾å‚æ•°çš„å½±å“å› ç´ .

OBJECTIVES: The number of gestational women has been increased in recent years, resulting in more adverse pregnancy outcomes. It is crucial to assess the coagulation function of pregnant women and to intervene in a timely manner. This study aims to analyze the influencing factors on thrombelastography (TEG) and explore the evaluation of TEG for gestational women. METHODS: A retrospective study was conducted on 449 pregnant women who were hospitalized in the obstetrics department in Xiangya Hospital of Central South University from 2018 to 2020. We compared the changes on the TEG parameters among normal pregnant women between different age groups, different ingravidation groups, and different stages of pregnancy groups. The influence on TEG of hypertensive disorders in pregnancy (HDP) and gestational diabetes mellitus (GDM) as well as two diseases synchronization was explored. RESULTS: Compared with the normal second trimester women, the R values and K values of TEG were increased, and α angle, CI values and LY30 values were decreased in third trimester women (all P<0.05). Compared with normal group, the R values and CI values of TEG of the HDP group have significant difference (both P<0.05). There were no significant difference of TEG between the GDM group, the HDP combined with GDM group and the normal group (all P>0.05). Multiple linear regression analysis showed that the influencing factors for R value in TEG were weeks of gestation (P<0.001) and mode of conception (P<0.05), for α angle was weeks of gestation (P<0.05), for MA value was mode of conception (P<0.05), and for CI value was weeks of gestation (P<0.05). The analysis of correlation between TEG with platelet (PLT) and coagulation routines represented that there was a correlation between TEG R values and activated partial thromboplastin time (APTT) (P<0.01), and negative correlation between TEG CI values and APTT (P<0.05). There was a negative correlation between TEG K values and FIB (P<0.05). The correlation of α angle (P<0.05), MA values (P<0.01) and CI values (P<0.05) with FIB were positive respectively. CONCLUSIONS: The TEG parameters of 3 stages of pregnancy were different. The different ingravidation approach has effect on TEG. The TEG parameters were consistent with conventional coagulation indicators. The TEG can be used to screen the coagulation status of gestational women, recognize the abnormalities of coagulation and prevent the severe complication timely.

Global haemostatic tests demonstrate the absence of parameters of hypercoagulability in non-hypoxic mild COVID-19 patients: a prospective matched study.

Severe COVID-19 patients demonstrate hypercoagulability, necessitating thromboprophylaxis. However, less is known about the haemostatic profile in mild COVID-19 patients. We performed an age and gender-matched prospective study of 10 severe and 10 mild COVID-19 patients. Comprehensive coagulation profiling together with Thromboelastography and Clot Waveform Analysis were performed. FBC, PT, APTT, D-dimer, fibrinogen and CWA were repeated every 3 days for both groups and repeat TEG was performed for severe patients up till 15 days. On recruitment, severe patients had markers reflecting hypercoagulability including raised median D-dimer 1.0 µg/mL (IQR 0.6, 1.4) (p = 0.0004), fibrinogen 5.6 g/L (IQR 4.9, 6.6) (p = 0.002), Factor VIII 206% (IQR 171, 203) and vWF levels 265.5% (IQR 206, 321). Mild patients had normal values of PT, aPTT, fibrinogen and D-dimer, and slightly elevated median Factor VIII and von Willebrand factor (vWF) levels. Repeated 3-day assessments for both groups showed declining trends in D-dimer and Fibrinogen. CWA of severe COVID-19 group demonstrated hypercoagulability with an elevated median values of aPTT delta change 78.8% (IQR 69.8, 85.2) (p = 0.001), aPTT clot velocity (min1) 7.8%/s (IQR 6.7, 8.3) (p = 0.001), PT delta change 22.4% (IQR 19.4, 29.5) (p = 0.004), PT min1 7.1%/s (IQR 6.3, 9.0) (p = 0.02), PT clot acceleration (min 2) 3.6%/s2 (IQR 3.2, 4.5) (p = 0.02) and PT clot deceleration (max2) 2.9%/s2 (IQR 2.5, 3.5) (p = 0.02). TEG of severe patients reflected hypercoagulability with significant increases in the median values of CFF MA 34.6 mm (IQR 27.4,38.6) (p = 0.003), CRT Angle 78.9° (IQR 78.3, 80.0) (p = 0.0006), CRT A10 67.6 mm (IQR 65.8, 69.6) (p = 0.007) and CFF A10 32.0 mm (IQR 26.8, 34.0) (p = 0.003). Mild COVID-19 patients had absent hypercoagulability in both CWA and TEG. 2 severe patients developed thromboembolic events while none occurred in the mild COVID-19 group. Mild COVID-19 patients show absent parameters of hypercoagulability in global haemostatic tests while those with severe COVID-19 demonstrated parameters associated with hypercoagulability on the global haemostatic tests together with raised D-Dimer, fibrinogen, Factor VIII and vWF levels.

Apolipoprotein A-I, elevated in trauma patients, inhibits platelet activation and decreases clot strength.

Apolipoprotein A-I (ApoA-I) is elevated in the plasma of a subgroup of trauma patients with systemic hyperfibrinolysis. We hypothesize that apoA-I inhibits platelet activation and clot formation. The effects of apoA-I on human platelet activation and clot formation were assessed by whole blood thrombelastography (TEG), platelet aggregometry, P-selectin surface expression, microfluidic adhesion, and Akt phosphorylation. Mouse models of carotid artery thrombosis and pulmonary embolism were used to assess the effects of apoA-I in vivo. The ApoA-1 receptor was investigated with transgenic mice knockouts (KO) for the scavenger receptor class B member 1 (SR-BI). Compared to controls, exogenous human apoA-I inhibited arachidonic acid and collagen-mediated human and mouse platelet aggregation, decreased P-selectin surface expression and Akt activation, resulting in diminished clot strength and increased clot lysis by TEG. ApoA-I also decreased platelet aggregate size formed on a collagen surface under flow. In vivo, apoA-I delayed vessel occlusion in an arterial thrombosis model and conferred a survival advantage in a pulmonary embolism model. SR-BI KO mice significantly reduced apoA-I inhibition of platelet aggregation versus wild-type platelets. Exogenous human apoA-I inhibits platelet activation, decreases clot strength and stability, and protects mice from arterial and venous thrombosis via the SR-BI receptor.

Thrombelastography (TEG® 6s) early amplitudes predict maximum amplitude in severely injured trauma patients.

Severely injured trauma patients are often coagulopathic and early hemostatic resuscitation is essential. Previous studies have revealed linear relationships between thrombelastography (TEG®) five- and ten-min amplitudes (A5 and A10), and maximum amplitude (MA), using TEG® 5000 technology. We aimed to investigate the performance of A5 and A10 in predicting low MA in severely injured trauma patients and identify optimal cut-off values for hemostatic intervention based on early amplitudes, using the cartridge-based TEG® 6s technology. Adult trauma patients with hemorrhagic shock were included in the iTACTIC randomized controlled trial at six European Level I trauma centers between 2016 and 2018. After admission, patients were randomized to hemostatic therapy guided by conventional coagulation tests (CCT) or viscoelastic hemostatic assays (VHA). Patients with available admission-TEG® 6s data were included in the analysis, regardless of treatment allocation. Low MA was defined as <55 mm for Kaolin TEG® and RapidTEG®, and <17 mm for TEG® functional fibrinogen (FF). One hundred eighty-seven patients were included. Median time to MA was 20 (Kaolin TEG®), 21 (RapidTEG®) and 12 (TEG® FF) min. For Kaolin TEG®, the optimal Youden index (YI) was at A5 < 36 mm (100/93% sensitivity/specificity) and A10 < 47 mm (100/96% sensitivity/specificity). RapidTEG® optimal YI was at A5 < 34 mm (98/92% sensitivity/specificity) and A10 < 45 mm (96/95% sensitivity/specificity). TEG® FF optimal YI was at A5 < 12 mm (97/93% sensitivity/specificity) and A10 < 15 mm (97/99% sensitivity/specificity). In summary, we found that TEG® 6s early amplitudes were sensitive and specific predictors of MA in severely injured trauma patients. Intervening on early amplitudes can save valuable time in hemostatic resuscitation.

Comparison of two individualized antithrombotic protocols in HeartWare HVAD recipients.

We previously reported low rates of pump thrombosis and hemorrhagic stroke, but increased bleeding, under our original antithrombosis protocol (P1) in HeartWare recipients. We designed and implemented a revised protocol (P2) to reduce complexity and bleeding. Thrombelastography and PFA-100 guide antiplatelet titration. Goals for P2 were altered to decrease antiplatelet use and anticoagulation intensity. We compared the incidence and rates of gastrointestinal bleeding (GIB), embolic (eCVA) and hemorrhagic (hCVA) stroke, pump thrombosis (PT), and total bleeding (GIB+hCVA), total thrombosis (eCVA+PT), and total events between P1 and P2. Laboratory and medication data were assessed. Patients with and without hemocompatibility-related adverse events (HRAEs) were compared. The study included 123 patients (P1: 65; P2: 58). GIB rate decreased (P1: 0.66; P2 0.30 EPPY, P = .003). CVA rates and incidence were statistically similar, although hCVA incidence increased (P1: 3%; P2: 12%, P = .06). Incidence (P1: 3%; P2: 16%, P = .02) and rate (P1: 0.03; P2: 0.12 EPPY, P = .08) of PT increased. Incidence and rate of overall HRAEs and thrombotic events were similar, while bleeding rate decreased (P1: 0.69; P2: 0.40 EPPY, P = .02). Twelve-month medication burden decreased. Compared to non-HRAE patients, patients with bleeding HRAEs had more antiplatelet and pentoxifylline use, but less statin use; and lower PFAs. Patients with thrombotic HRAEs had less dual antiplatelet use, lower INRs, R-times, and PFA-ADP values. A revised antithrombotic protocol decreased GIB and overall hemorrhagic HRAE rate and medication burden. Unfortunately, PT increased. Non-HRAE and HRAE patients differed in anticoagulation and antiplatelet intensity. These differences will guide the revision of P2.

Real-life experiences with goal-directed prohemostatic therapy with fibrinogen concentrate, prothrombin complex concentrate, and recombinant factor VIIa: a retrospective study of 287 consecutive patients.

The Danish Capital Region Blood Bank operates a 24/7 on-call service staffed with physicians specialized in hemostatic management to guide clinicians in hemostatic resuscitation, including administration of prohemostatic therapy (PHT). The outcome of patients who receive PHT as part of hemostatic resuscitation remains unanswered. The objective of this study was therefore to investigate clinical outcome of patients receiving PHT managed by the on-call service. We identified 287 patients who received PHT during 2015-16, of which 161 (59%) received fibrinogen concentrate (FC), 111 (39%) received prothrombin complex concentrate (PCC), and 15 (5%) received recombinant factor VIIa (rFVIIa) as the first product. Patients were critically ill with a 30-day mortality of 31%. Among FC recipients, cardiothoracic admission, non-trauma, and antithrombotics predicted survival. FC recipients had lower platelet count and thrombelastography clot strengths than the other PHT groups and within the group, these factors predicted mortality. The symptomatic thromboembolic event (TE) rate at 30 days was 5%. For PCC recipients, vitamin K antagonists predicted survival, while rivaroxaban predicted mortality. TE rate was 2%. We did not identify factors associated with survival in the small group of rFVIIa recipients. TE rate was 13%. In summary, trauma and coagulopathy predicted mortality in patients who received FC and our data suggest that optimization of PHT algorithms may be possible. Outcome of patients who received PCC was comparable to results reported elsewhere and its use may be safe in a setting as reported here. Recombinant FVIIa was rarely used but had the highest incidence of arterial thromboembolism.

Injury Severity, Arrival Physiology, Coagulopathy, and Outcomes Among the Youngest Trauma Patients.

BACKGROUND: Although physiologic differences exist between younger and older children, pediatric trauma analyses are weighted toward older patients. Trauma-induced coagulopathy, determined by rapid thrombelastography (rTEG), is a predictor of outcome in trauma patients, but the significance of rTEG values among very young trauma patients remains unknown. Our objective was to identify the prehospital or physiologic factors, including rTEG values, that were associated with mortality in trauma patients younger than 5 y old. MATERIALS AND METHODS: Patients younger than 5 y old that met the highest-level trauma activation criteria at an academic children's hospital from 2010-2016 were included. Data regarding demographics, pre-hospital management, laboratory values, injury severity, and outcome were queried. Univariate and multivariate analyses were performed comparing survivors and non-survivors. RESULTS: A total of 356 patients were included. 60% were male, and the median age was 3 y (IQR 1-4). Overall mortality was 13% (n = 45); brain injury (91%) and hemorrhage (9%) were the causes of death. Compared to survivors, rTEG values in nonsurvivors showed longer activated clotting time and slower speed of clot formation. Clot strength was also decreased in nonsurvivors. On stepwise regression modeling, rTEG values were not significant predictors of mortality. Admission base deficit, arrival temperature, and head injury severity were identified as independent predictors of mortality. CONCLUSIONS: While rTEG identified coagulopathy in trauma patients < 5 y old, it was not an independent predictor of mortality. Our findings suggest that trauma providers should pay close attention to admission base deficit, arrival temperature, and head injury severity when managing the youngest trauma patients.

Prevalence and impact of fibrinolytic dysregulation in patients with acute coronary syndromes.

OBJECTIVE: Dual antiplatelet therapy can reduce coronary thrombosis and improve the prognosis in patients with acute coronary syndrome (ACS). However, there was limited prognostic information about fibrinolytic dysregulation in patients with ACS. This study is aimed to evaluated the prevalence and impact of fibrinolytic dysregulation in patients with acute coronary syndrome (ACS). METHODS: We retrospectively analyzed coagulation and fibrinolysis related indexes of ACS in hospitalized adults with rapid thrombelastography between May 2016 and December 2018. All of the follow-up visits were ended by December 2019. The primary outcome was the occurrence of major adverse cardiovascular events (MACEs), which included unstable angina pectoris, non-fatal myocardial infarction, non-fatal cerebral infarction, heart failure and all-cause death. RESULTS: Three hundred thirty-eight patients were finally included with an average age of 62.5 ± 12.8 years old, 273 (80.5%) were males, 137(40.5%) patients were with ST-elevation myocardial infraction. Fibrinolysis shutdown (LY30<0.8%) and hyperfibrinolysis (LY30 >3.0%) were observed among 163 (48.2%) and 76(22.5%) patients, respectively. During a total of 603.2 person·years of follow-up period, 77 MACEs occurred (22.8%). Multivariate Cox regression analysis indicated that LY30 [HR: 1.101, 95% CI: 1.010-1.200, P = 0.028] was independently correlated with the occurrence of MACEs. The hazard ratios pertaining to MACEs in patients with fibrinolysis shutdown and hyperfibrinolysis compared with those in the physiologic range (LY30: 0.8-3.0%) were 1.196 [HR: 1.196, 95% CI: 0.679-2.109,P = 0.535] and 2.275 [HR: 2.275, 95% CI: 1.241-4.172, P = 0.003], respectively. CONCLUSIONS: Fibrinolytic dysregulation is very common in selected patients with ACS, and hyperfibrinolysis (LY30 > 3%) is associated with poor outcomes in patients with ACS.

Association of lipoprotein(a) with platelet aggregation and thrombogenicity in patients undergoing percutaneous coronary intervention.

This study aimed to evaluate the association of lipoprotein(a) levels with platelet aggregation and thrombogenicity in patients undergoing percutaneous coronary intervention (PCI), and to investigate the ischemic outcome on this population. Lipoprotein(a) and modified thrombelastography were measured in 6601 consecutive patients underwent PCI on dual antiplatelet therapy. Cox proportional regression analysis was applied to illustrate the ischemic events in a 2-year follow up. The mean levels of lipoprotein(a) were 29.0 mg/dl. Patients with higher lipoprotein(a) levels had significantly accelerated fibrin generation (lower K time and bigger α angle) and greater clot strength (higher maximum amplitude (MA)) than patients with lower lipoprotein(a) levels (P < .001). Moreover, the higher lipoprotein(a) group also exhibited significantly higher adenosine diphosphate (ADP) induced platelet aggregation (MAADP) by thrombelastography platelet mapping assay than lower lipoprotein(a) group. Cox regression analyzes revealed that patients with higher lipoprotein(a) levels had a 16% higher risk of major adverse cardiovascular and cerebrovascular events (HR 1.159, 95%CI: 1.005-1.337, P = .042) compared with patients with lower lipoprotein(a) levels. This association persisted after adjustment for a broad spectrum of risk factors (HR 1.174, 95%CI: 1.017-1.355, P = .028). High plasma lipoprotein(a) levels were associated with increased platelet aggregation and ischemic events in patients underwent PCI. Lipoprotein(a) might indicate the need for prolonged antiplatelet therapy.

Managing patients on direct factor Xa inhibitors with rapid thrombelastography.

The use of direct factor Xa inhibitors rivaroxaban and apixaban (XABANs) has rapidly increased; however, there is no validated test available to monitor the effect on hemostasis. This study aims to assess how hemostatic management based on the Rapid Thromboelastography (R-TEG) variable activated clotting time (ACT) of XABAN patients with ongoing bleedings or in need for acute surgical intervention, affected patient outcome. A total of 343 XABAN patients were included in the main analysis together with 50 healthy volunteers to validate the reference value for ACT. An ACT >120 s (s) was defined as having XABAN-induced coagulopathy. Sixty-five percent of the XABAN patients presented with R-TEG ACT within the normal reference. Patients with XABAN-induced coagulopathy had a significantly increased risk of severe bleeding. Significantly more patients with extra-cerebral bleeding (ECB) and ACT above 120 s were transfused with five red blood cell (RBC) units or more compared to patients with ACT at 120 s or below (17% vs. 3%, p <.05). Significantly more XABAN-patients with ACT above 120 s received pro-hemostatic intervention with prothrombin complex concentrate (PCC) when compared to those with ACT at 120 s or below (ECB: 2% vs. 8%, p =.03, intracranial hemorrhage: 25% vs. 68%, p <.00). Patients who received PCC had a higher 30- and 90-day mortality compared to the rest of the cohort (16% vs. 6%, p = .02 and 21% vs. 7%, p =.00). Patients with XABAN-induced coagulopathy as evaluated by R-TEG ACT presented with more severe bleeding and higher transfusion requirements when compared to those with ACT in the normal range. This suggests that R-TEG ACT measurement in XABAN patients with active hemorrhage or in need for acute surgery may be of clinical value.

It is time for TEG in pediatric trauma: unveiling meaningful alterations in children who undergo massive transfusion.

BACKGROUND: Hemorrhage is the leading cause of preventable death in pediatric trauma patients. In adults, goal-directed thrombelastography (TEG) has been shown to reduce mortality when used to guide massive transfusion (MT) resuscitation. There remains a paucity of data on the utility of TEG in directing resuscitation of pediatric trauma patients. We hypothesize that abnormalities on admission TEG will differ in pediatric trauma patients who undergo MT, compared to those who do not. METHODS: Pediatric patients (≤ 18 years) who were highest level trauma activations at two trauma centers from 2015 to 2018 were analyzed. We included patients who had admission TEGs and excluded those who did not. Patients were stratified into two groups: those who received MT (> 40 cc/kg total blood product within 6 h of admission) and those who did not. We defined TEG abnormalities based on each institution's normative values and compared TEG abnormalities between the groups. RESULTS: Of 117 children included, 39 had MT. MT patients had higher injury severity scores (30 vs. 23, p = 0.0004), lactates levels (7.0 vs. 3.5, p < 0.001), base deficit levels ( - 12.2 vs. - 5.8, p < 0.001), and INR values (1.8 vs. 1.3, p < 0.001). MT patients had significantly shortened alpha-angles (35.9% vs. 15.4%, p = 0.023), maximum amplitude (MA) values (43.6% vs. 10.3%, p < 0.001), and significantly lower platelet counts (165 vs. 281, p < 0.001) compared to those who did not receive MT. There was no difference in the trends in R-time, LY30 (lysis or shutdown), or fibrinogen concentration between the groups. Logistic regression identified a decreased MA as a significant predictor for MT [OR 3.68 (CI 1.29-10.52)] CONCLUSIONS: Pediatric trauma patients who undergo MT are more likely to have lower alpha-angles and MA values, as well as lower platelet counts. These findings support the use of TEG to identify hemorrhaging pediatric trauma patients, who may benefit from cryoprecipitate and/or platelet transfusions. TEG provides real-time information on coagulation status, which may expedite the delivery of specific blood products during trauma resuscitation. LEVEL OF EVIDENCE: LEVEL III: Type of study: Retrospective comparative study.

Modulation of Diverse Procoagulant Venom Activities by Combinations of Platinoid Compounds.

Procoagulant snake venoms have been inhibited by the ruthenium containing compounds CORM-2 and RuCl3 separately, presumably by interacting with critical histidine or other sulfur-containing amino acids on key venom enzymes. However, combinations of these and other platinoid containing compounds could potentially increase, decrease or not affect the procoagulant enzyme function of venom. Thus, the purpose of this investigation was to determine if formulations of platinoid compounds could inhibit venom procoagulant activity and if the formulated compounds interacted to enhance inhibition. Using a human plasma coagulation kinetic model to assess venom activity, six diverse venoms were exposed to various combinations and concentrations of CORM-2, CORM-3, RuCl3 and carboplatin (a platinum containing compound), with changes in venom activity determined with thrombelastography. The combinations of CORM-2 or CORM-3 with RuCl3 were found to enhance inhibition significantly, but not in all venoms nor to the same extent. In sharp contrast, carboplatin-antagonized CORM-2 mediated the inhibition of venom activity. These preliminary results support the concept that platinoid compounds may inhibit venom enzymatic activity at the same or different molecular sites and may antagonize inhibition at the same or different sites. Further investigation is warranted to determine if platinoid formulations may serve as potential antivenoms.

Inhaled nitric oxide to control platelet hyper-reactivity in patients with acute submassive pulmonary embolism.

BACKGROUND: We test if inhaled nitric oxide (NO) attenuates platelet functional and metabolic hyper-reactivity in subjects with submassive pulmonary embolism (PE). METHODS: Participants with PE were randomized to either 50 ppm NO + O2 or O2 only for 24 h with blood sampling at enrollment and after treatment; results were compared with healthy controls. Platelet metabolic activity was assessed by oxygen consumption (basal and uncoupled) and reactivity was assessed with agonist-stimulated thromboelastography (TEG) and fluorometric measurement of agonist-stimulated cytosolic [Ca++] without and with pharmacological soluble guanylate (sGC) modulation. RESULTS: Participants (N = 38 per group) were well-matched at enrollment for PE severity, comorbidities as well as TEG parameters and platelet O2 consumption. NO treatment doubled the mean plasma [NO3-] (P < 0.001) indicating successful delivery, but placebo treatment produced no change. After 24 h, neither TEG nor O2 consumption parameters differed significantly between treatment groups. Platelet cytosolic [Ca++] was elevated with PE versus controls, and was decreased by treatment with cinaciguat (an sGC activator), but not riociguat (an sGC stimulator). Stimulated platelet lysate sGC activity was increased with PE compared with controls. CONCLUSIONS: In patients with acute submassive PE, despite evidence of adequate drug delivery, inhaled NO had no major effect on platelet O2 consumption or agonist-stimulated parameters on TEG. Pharmacological activation, but not stimulation, of sGC effectively decreased platelet cytosolic [Ca++], and platelet sGC activity was increased with PE, confirming the viability of sGC as a therapeutic target.