Rotational Thromboelastometry in High-Risk Patients on Dual Antithrombotic Therapy After Percutaneous Coronary Intervention

Aims: Patients using antithrombotic drugs after percutaneous coronary intervention (PCI) are at risk for bleeding and recurrent ischemia. We aimed to explore routine and tissue plasminogen activated (tPA) ROTEM results in a post-PCI population on dual antithrombotic treatment.Methods and Results: In this prospective cohort, 440 patients treated with double antithrombotic therapy after recent PCI and with ≥3 risk factors for either ischemic or bleeding complications were included and compared with a control group (n = 95) consisting of perioperative patients not using antithrombotic medication. Laboratory assessment, including (tPA) ROTEM, was performed one month post-PCI and bleeding/ischemic complications were collected over a five-month follow-up. Patients were stratified by antithrombotic regimen consisting of a P2Y12 inhibitor with either aspirin (dual antiplatelet therapy; DAPT, n = 323), a vitamin K antagonist (VKA, n = 69) or a direct oral anticoagulant (DOAC, n = 48). All post-PCI patients had elevated ROTEM clot stiffness values, but only the DAPT group additionally presented with a decreased fibrinolytic potential as measured with tPA ROTEM. Patients receiving anticoagulants had prolonged clotting times (CT) when compared to the control and DAPT group; EXTEM and FIBTEM CT could best discriminate between patients (not) using anticoagulants (AUC > 0.97). Furthermore, EXTEM CT was significantly prolonged in DAPT patients with bleeding complications during follow-up (68 [62–70] vs. 62 [57–68], p = 0.030).Conclusion: ROTEM CT has high potential for identifying anticoagulants and tPA ROTEM could detect a diminished fibrinolytic potential in patients using DAPT. Furthermore, the ability of EXTEM CT to identify patients at risk for bleeding may be promising and warrants further research.

Features of thrombocyte-vascular hemostasis in women with abnormal uterine bleeding and submucosal uterine fibroids

Objective – to investigate the features of platelet-vascular hemostasis in women with abnormal uterine bleeding on the background of submucosal uterine fibroids.Material and methods. The study included 30 women with abnormal uterine bleeding with submucosal uterine fibroids. Features of thrombocyte-vascular hemostasis were studiedResults. There are new data in relation to the features of certain links of the adjusting system of the aggregate state of blood on a background development of post hemorrhage anaemia. It is clearly shown that changes in the system of adjusting of the aggregate state of blood in women with a severe degree of anaemisation are the display of subclinical inopexi.Conclusions. Changes in the fibrinolytic potential of blood in women with chronic posthemorrhagic anemia on the background of abnormal uterine bleeding and submucosal uterine fibroids are secondary, due to the activation of thrombin and fibrinogenesis by external mechanisms.

Increased Expression of Extracellular Vesicles Is Associated With the Procoagulant State in Patients With Established Rheumatoid Arthritis

This study sought to identify different subpopulations of extracellular vesicles (EVs) in plasma from female patients with established rheumatoid arthritis (RA) in relation to the activation of coagulation and fibrin formation in these patients. Forty women were included in the study, 20 patients and 20 age-matched healthy controls. The mean disease duration in patients was 13.0 (5.0–25.0) years, with medium to high disease activity despite ongoing treatment with low-dose prednisolone and methotrexate. There were no differences between the investigated groups regarding the presence of traditional cardiovascular risk factors. The concentration of phosphatidylserine-positive (PS+) EVs; platelet (CD42a+), leucocyte (CD45+), monocyte (CD14+), and endothelial (CD144+)-derived EVs; and EVs-expressing tissue factor (CD142+), P-selectin (CD62P+), and E-selectin (CD62E+) were determined by flow cytometry analysis. Overall hemostasis potential (OHP) was assessed to follow the hemostatic disturbances, including the parameters for overall coagulation potential (OCP) and overall fibrinolytic potential (OFP). Fibrin clot turbidity was measured together with clot lysis time, and scanning electron microscopy was performed. Increased concentrations of PS+, CD42a+, CD142+, CD45+, CD14+, and CD62P+ EVs were found in plasma from patients with RA compared to healthy controls, and the concentrations of PS+, CD42a+, CD14+, and CD62P+ EVs were positively correlated with the inflammatory parameters in RA patients. Positive correlations were also found between the levels of PS+ and CD42a+ EVs and OCP as well as between the levels of PS+, CD42a+, and CD62P+EVs and OHP. The levels of PS+, CD42a+, CD14+, CD62P+, and CD62E+ EVs were negatively correlated with OFP. Elevated levels of circulating EVs of different cell origins were found in patients with established RA, in relation to the inflammatory burden and coagulation activation in the disease.

Inhalation Injury is Associated with Endotheliopathy and Abnormal Fibrinolytic Phenotypes in Burn Patients: A Cohort Study

Burn injury is associated with endothelial dysfunction and coagulopathy and concomitant inhalation injury increases morbidity and mortality. The aim of this work is to identify associations between inhalation injury (IHI), coagulation homeostasis, vascular endothelium, and clinical outcomes in burn patients. One-hundred and twelve patients presenting to a regional burn center were included in this retrospective cohort study. Whole blood was collected at set intervals from admission through 24 hours and underwent viscoelastic assay with rapid TEG (rTEG). Syndecan-1 (SDC-1) on admission was quantified by ELISA. Patients were grouped by the presence (n=28) or absence (n=84) of concomitant IHI and rTEG parameters, fibrinolytic phenotypes, SDC-1, and clinical outcomes were compared. Of the 112 thermally injured patients, 28 (25%) had IHI. Most patients were male (68.8%) with a median age of 40 (IQR, 29-57) years. Patients with IHI had higher overall mortality (42.68% vs. 8.3%; p<0.0001). rTEG LY30 was lower in patients with IHI at hours 4 and 12 (p<0.05). There was a pattern of increased abnormal fibrinolytic phenotypes among IHI patients. There was a greater proportion of IHI patients with endotheliopathy (SDC-1 > 34 ng/mL) (64.7% vs. 26.4%; p=0.008). There was a pattern of increased mortality among patients with inhalation injury and endotheliopathy (0% vs. 72.7%; p=0.004). Significant differences between patients with and without IHI were found in measures assessing fibrinolytic potential and endotheliopathy. Mortality was associated with abnormal fibrinolysis, endotheliopathy, and inhalation injury. However, the extent to which IHI associated dysfunction is independent of TBSA burn size remains to be elucidated.

Plasma Hemostasis in Patients with Essential Hypertension and Non-alcoholic Fatty Liver Disease Under Conditions of Hypercholesterolemia and Concomitant Statin Therapy

In the modern scientific world, it has been proven that non-alcoholic fatty liver disease (NAFLD) is a marker of the risk of cardiovascular (CV) events, and therefore, attention and control of risk factors for CV diseases is important. Considering the prevalence of atherogenic dyslipidemias and their proven effect on the development of thrombotic CV complications in patients with NAFLD, it is important to understand the role of hemostatic blood activity. The objective: To increase the efficiency of early diagnosis of thrombophilic changes in the blood in patients with essential hypertension (HT) combined with non-alcoholic fatty liver disease by determining the state of plasma hemostasis in conditions of hypercholesterolemia and concomitant statin therapy. Materials and methods. 152 patients were examined. Patient groups: I – 46 patients with stage II hypertension, II – 54 patients with NAFLD without hypertension, group III – 52 patients with stage II hypertension with concomitant NAFLD. Results. The growth of prothrombogenic activity of the blood among all groups of patients, however, with HT II stage, combined with NAFLD, the most significant effect was carried out precisely on the final stages of coagulation. An increase in the level of fibrinogen was observed in patients with grade II hypertension. by 29,3 % (p<0,01) and with a combination of HT and NAFLD by 39,7 % (p<0,001). The levels of soluble fibrin-monomeric complexes in all groups were significantly higher than the control values: in patients with hypertension. – 4,1 times (p<0,001), with NAFLD – 2,8 times (p<0,001), in the NAFLD group with hypertension – 4,5 times (p<0,001). Antithrombin III (AT III) was reduced by 12,3 % (p<0,01) relative to the control only in patients with hypertension. On the other hand, the fibrinolytic potential was reduced among all examined groups. Determination of the effect of lipid-lowering therapy revealed an acceleration of prothrombin time (PTT) by 19.2 % (p<0,01) in patients with NAFLD without statin treatment. In the general cohort, statin use increased the activity of AT III by 10,7 % (p<0,01), but in the NAFLD group, this difference was more significant – by 14,3 % (p<0,001). In patients with comorbid course of HT and NAFLD with cholesterolemia level <5 mmol/L, we observed an increase in PTT by 32,5 % (p<0,05), INR by 25,4 % (p<0,05) and thrombin time by 23,2 % (p<0,05) during statin therapy. On the other hand, in the subgroup with hypercholesterolemia, statins increased the activity of the anticoagulant link of hemostasis – the level of ATIII increased by 3,1 % (p<0,05). Conclusions. Depletion of the fibrinolytic potential against the background of activation of the coagulant hemostasis link is observed in patients with hypertension combined with NAFLD. In the case of concomitant hypercholesterolemia, the procoagulant activity of the blood increases, however, against the background of treatment with statins, there is a decrease in the coagulation potential of the blood and an increase in the activity of the anticoagulant link of hemostasis.

Role of Shear Stress and tPA Concentration in the Fibrinolytic Potential of Thrombi

The resolution of arterial thrombi is critically dependent on the endogenous fibrinolytic system. Using well-established and complementary whole blood models, we investigated the endogenous fibrinolytic potential of the tissue-type plasminogen activator (tPA) and the intra-thrombus distribution of fibrinolytic proteins, formed ex vivo under shear. tPA was present at physiologically relevant concentrations and fibrinolysis was monitored using an FITC-labelled fibrinogen tracer. Thrombi were formed from anticoagulated blood using a Chandler Loop and from non-anticoagulated blood perfused over specially-prepared porcine aorta strips under low (212 s−1) and high shear (1690 s−1) conditions in a Badimon Chamber. Plasminogen, tPA and plasminogen activator inhibitor-1 (PAI-1) concentrations were measured by ELISA. The tPA–PAI-1 complex was abundant in Chandler model thrombi serum. In contrast, free tPA was evident in the head of thrombi and correlated with fibrinolytic activity. Badimon thrombi formed under high shear conditions were more resistant to fibrinolysis than those formed at low shear. Plasminogen and tPA concentrations were elevated in thrombi formed at low shear, while PAI-1 concentrations were augmented at high shear rates. In conclusion, tPA primarily localises to the thrombus head in a free and active form. Thrombi formed at high shear incorporate less tPA and plasminogen and increased PAI-1, thereby enhancing resistance to degradation.

Fibrinolysis as a target to enhance osteoporotic fracture healing by vibration therapy in a metaphyseal fracture model

Aims Fibrinolysis plays a key transition step from haematoma formation to angiogenesis and fracture healing. Low-magnitude high-frequency vibration (LMHFV) is a non-invasive biophysical modality proven to enhance fibrinolytic factors. This study investigates the effect of LMHFV on fibrinolysis in a clinically relevant animal model to accelerate osteoporotic fracture healing. Methods A total of 144 rats were randomized to four groups: sham control; sham and LMHFV; ovariectomized (OVX); and ovariectomized and LMHFV (OVX-VT). Fibrinolytic potential was evaluated by quantifying fibrin, tissue plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) along with healing outcomes at three days, one week, two weeks, and six weeks post-fracture. Results All rats achieved healing, and x-ray relative radiopacity for OVX-VT was significantly higher compared to OVX at week 2. Martius Scarlet Blue (MSB) staining revealed a significant decrease of fibrin content in the callus in OVX-VT compared with OVX on day 3 (p = 0.020). Mean tPA from muscle was significantly higher for OVX-VT compared to OVX (p = 0.020) on day 3. Mechanical testing revealed the mean energy to failure was significantly higher for OVX-VT at 37.6 N mm (SD 8.4) and 71.9 N mm (SD 30.7) compared with OVX at 5.76 N mm (SD 7.1) (p = 0.010) and 17.7 N mm (SD 11.5) (p = 0.030) at week 2 and week 6, respectively. Conclusion Metaphyseal fracture healing is enhanced by LMHFV, and one of the important molecular pathways it acts on is fibrinolysis. LMHFV is a promising intervention for osteoporotic metaphyseal fracture healing. The improved mechanical properties, acceleration of fracture healing, and safety justify its role into translation to future clinical studies. Cite this article: Bone Joint Res 2021;10(1):41–50.