Prothrombin Fragment Research Articles

Extent of peritoneal metastases from colorectal cancer is not associated with changes in thrombin generation or fibrinolysis

Abstract Objectives Cancer cells can activate coagulation and inhibit fibrinolysis. The aim was to investigate the association between the burden of peritoneal metastases from colorectal cancer (PM-CRC) and biomarkers reflecting thrombin generation and fibrinolysis. Methods A cohort of 55 patients with PM-CRC scheduled for cytoreductive surgery. Patients were grouped by the peritoneal cancer index (PCI) assessed intraoperatively into limited PM-CRC (PCI≤15) and extensive PM-CRC (PCI>15). Blood samples were obtained before surgery. Thrombin generation was measured in vivo by thrombin-antithrombin complex (TAT) and prothrombin fragment 1+2 (F1+2), and ex vivo by the endogenous thrombin potential (ETP). Fibrinolysis was analyzed with fibrin clot lysis assay, fibrinogen, and D-dimer. Results Non-significantly decreased thrombin generation by F1+2 (p=0.72), TAT (p=0.32), and ETP (p=0.19) were observed in patients with extensive PM-CRC (n=9) compared with limited PM-CRC (n=46). Non-significantly prolonged 50 % clot lysis time were found in patients with extensive PM-CRC than in patients with limited PM-CRC. Conclusions Minor non-significant differences in thrombin generation and fibrinolysis were found between patients with extensive PM-CRC and limited PM-CRC. Thus, increased peritoneal metastatic burden from colorectal cancer does not seem to affect thrombin generation and fibrinolysis.

Endothelial dysfunction markers syndecan-1 and thrombomodulin are associated with higher albuminuria levels in type 2 diabetes with no history of clinical cardiovascular disease

IntroductionIndividuals with type 2 diabetes and increased albuminuria, a well-established marker of microvascular complications, are at a higher risk for cardiovascular disease (CVD) and premature mortality. Therefore, a better understanding of the underlying pathophysiology is needed to improve risk stratification and tailor prevention and intervention. MethodsWe conducted a cross-sectional study including 463 individuals with type 2 diabetes, various degrees of albuminuria and without CVD. We analysed the association between albuminuria and markers of endothelial function (thrombomodulin and syndecan-1), thrombin generation (thrombin-antithrombin complex, prothrombin fragment 1 + 2), fibrinogen, platelet function (activation using soluble plasma selectin and aggregation using Multiplate® Analyzer) using regression models. ResultsIn the study cohort 33 % were women, the mean ± SD age was 65 ± 9 years, and median [IQR] diabetes duration was 15 [9–20] years. In total, 344 (74 %) individuals had normal albuminuria, 87 (19 %) moderately- and 32 (7 %) severely increased albuminuria levels. Higher markers of endothelial function and fibrinogen were independently associated with higher albuminuria levels (p < 0.01). No association between albuminuria and markers of thrombin generation and platelet was demonstrated. ConclusionWe demonstrated an independent association between albuminuria and markers of endothelial function and fibrinogen in individuals with type 2 diabetes and no history of CVD.

Combined activation of complement and coagulation is associated with myocardial injury in ST-elevation myocardial infarction

Abstract Introduction Experimental data indicates that the complement system and the coagulation cascade can activate each other. The magnitude of this interaction in acute myocardial infarction is not known. We aimed to investigate a possible association between complement activation and coagulation activation in patients with acute ST-elevation myocardial infarction (STEMI), as well as how they relate to myocardial injury estimated by troponin T (TnT) and myocardial function assessed by echocardiography. Purpose To increase the understanding of the interaction between complement activation and coagulation activation in STEMI, and the clinical relevance to myocardial injury. Methods Blood samples were drawn after percutaneous coronary intervention (PCI) in 864 patients with STEMI. Myocardial function was measured as left ventricular ejection fraction (LVEF), estimated by visual approximation or Simpson biplane method within 3 months. Complement activation was assessed by ELISA of circulating levels of the terminal complement complex (TCC). Activation of coagulation was assessed by ELISA of prothrombin fragment 1+2 (F1+2) and D-dimer, and endogenous thrombin potential (ETP), analyzed by calibrated automated thrombogram assay. Results TCC was weakly correlated to F1+2 (r=0.086, p=0.012), D-dimer (r=0.176, p&amp;lt;0.001) and ETP (r=0.144, p&amp;lt;0.001). In univariate linear regression analysis, this association persisted for D-dimer and ETP. When adjusting for associated covariables, the association only persisted for ETP (Table 1). Patients with above-median TCC and D-dimer had significantly higher peak TnT (Figure 1). In logistic regression, having combined above-median TCC and D-dimer was predictive of an LVEF ≤40% (Table 2). Conclusion In this large STEMI cohort, complement activation by TCC was weakly associated with coagulation activation. Combined high levels of TCC and D-dimer were linked to higher peak TnT and lower LVEF, possibly reflecting greater myocardial injury. The interaction between complement and coagulation activation might be relevant for clinical outcomes in STEMI patients and warrants further investigation.

Increased platelet-leucocyte complexes do not result in coagulation activation in plateletpheresis donors.

Although plateletpheresis donation is commonly accepted as a safe procedure, its influence on platelet function, coagulation system and fibrinolysis is not completely elucidated. In this study, we tried to assess the effects of plateletpheresis on donor's hemostasis system by measuring platelet activation, development of platelet-leukocyte aggregates, and coagulation activation. Prospective observational study. We used flow cytometry to determine the levels of platelet-monocyte complexes (PMC) and platelet-neutrophil complexes (PNC). sP-selectin and prothrombin fragment (PF) 1 + 2 values were determined by ELISA. The PMC levels increased significantly seven days after apheresis in comparison with just after apheresis and 24 h after apheresis (p < 0.05). The PNC levels increased significantly seven days after apheresis compared to immediately after apheresis (p < 0.05). sP-selectin values decreased significantly immediately after apheresis (p < 0.05). While sP-selectin values increased seven days after apheresis in comparison with immediately after apheresis and 24 h after apheresis, but there were not statistically significant differences for sP-selectin levels (p > 0.05). PF1 + 2 levels decreased significantly immediately after apheresis compared to pre-apheresis (p < 0.05) and increased 24 h after apheresis and seven days after apheresis, but these differences were not statistically significant. We concluded that plateletpheresis affects platelet activation but does not cause any change in coagulation activation.

Comparative Analysis of Coagulation Activation in Rheumatoid Arthritis Patients Treated With TNF Inhibitors Versus JAK Inhibitors: A Prospective Study.

This study aims to investigate the activation of the coagulation system of RA patients and assess changes during anti-inflammatory treatment with tumor necrosis factor blockers (anti-TNF) and Janus kinase inhibitors (JAKi). Biomarkers for the coagulation system, including D-dimer, fibrinogen, prothrombin time, activated partial thrombin time, prothrombin fragment 1 + 2, thrombin-antithrombin complex (TAT), activated factor IX, antithrombin complex, and von Willebrand factor (vWF), were longitudinally measured in 83 RA patients treated with anti-TNF and 38 RA patients with JAKi. Data were collected at baseline, after 1, 3, and 6 months. The mean age was 57 (±14) years; 76% was female. The mean DAS28-CRP was 3.6 (±1.3) for anti-TNF users and 4.1 (±1.4) for JAKi users at baseline and declined in both groups. Baseline coagulation markers levels were comparable between groups. In anti-TNF users, D-dimer and fibrinogen levels significantly declined (-0.31 mg/L, p = 0.01 and -0.71 g/L, p < 0.001, respectively), whereas TAT significantly increased after 6 months follow-up (1.46 μg/L, p = 0.03) and no effect on vWF (p = 0.98). In JAKi users, vWF declined significantly during the 6 months follow-up (-37.41%, p < 0.001); additionally, there were reductions of D-dimer, fibrinogen, and TAT that did not reach significance (-0.17 mg/L, p = 0.59; -0.49 g/L, p = 0.12; and 0.68 μg/L, p = 0.27, respectively). The prothrombotic tendency in active RA declined during effective treatment with both anti-TNF and JAKi. Altogether, the biomarkers used in this study suggest that an increased VTE risk in the first 6 months due to either treatment with anti-TNF or JAKi is unlikely.

Thromboprophylaxis in oesophageal cancer patients—a study protocol for a randomised, controlled trial (TOP-RCT)

BackgroundThe purpose of the study is to examine if prolonged thromboprophylaxis decreases the risk of thrombosis after intended curative surgery for oesophageal cancer.Study results are expected to inform a guideline for thromboprophylaxis after oesophageal cancer surgery. The perspective is to reduce morbidity and mortality in this critically ill patient group.Thrombosis is the second-most common cause of cancer death after the cancer itself. The risk of thrombosis depends on the cancer type, and upper gastrointestinal cancers are considered high risk. This risk is further increased when patients undergo surgery. However, only few studies have investigated the peri- and postoperative coagulation profile in oesophageal cancer patients. Due to this lack of knowledge, prophylaxis is currently restricted to 5000 IU (international units) low-molecular weight heparin daily from surgery until discharge from hospital (approximately 10 days), whereas patients with gastric cancer receive 30 days of treatment.The present study examines whether a 30-day treatment is superior and safe, compared with the current standard treatment.MethodsThe study is a randomised controlled trial. Inclusion is ongoing, and we aim to include 100 patients. Blood samples are drawn before and after surgery, and the coagulation is extensively examined. The primary endpoint is the difference in plasma levels of prothrombin fragment 1 + 2 (F1 + 2) 30 days after surgery between the intervention and the standard group. Furthermore, patients are examined with ultrasound to screen for asymptomatic venous thrombotic events (VTE).Secondary endpoints are incidence of bleeding, symptomatic and asymptomatic VTE and mortality 30 days 1 one year after surgery.DiscussionThe study will provide valuable information on the perioperative coagulation profile and VTE risk of oesophageal cancer patients. The study seeks to aid in optimising the postoperative thromboprophylaxis, and the perspective is to reduce morbidity and mortality in this at-risk patient population.Trials registrationThe trial was prospectively registered at the EU Clinical Trials Register with ID 2021–001335-24 on 30 June 2021 and at ClinicalTrials.gov with study identifier NCT05067153.

Enhanced venous thrombosis and hypercoagulability in murine and human metabolic dysfunction-associated steatohepatitis

BackgroundPatients with metabolic dysfunction-associated steatohepatitis (MASH) are at an increased risk of developing venous thromboembolic events, including deep vein thrombosis (DVT). To date, the study of DVT in MASH has been hampered by the lack of reliable models that mimic the pathologic aspects of human disease. ObjectivesTo evaluate DVT severity and hypercoagulability in murine and human MASH. MethodsTranscriptional changes in the liver, plasma markers of coagulation, and DVT severity were evaluated in mice fed a standard chow diet or a high-fructose, high-fat, and high-cholesterol MASH diet for 24 weeks. Plasma analyses of coagulation markers and thrombin generation assays were performed in a well-characterized cohort of patients with or without MASH. ResultsMice fed the MASH diet developed steatohepatitis and fibrosis, mimicking human MASH. Liver RNA sequencing revealed a significant upregulation of pathways related to inflammation and coagulation concomitant with increased levels of plasma coagulation markers including increased prothrombin fragment 1+2, thrombin-antithrombin complex, plasminogen activator inhibitor-1 levels, and endothelin 1. MASH exacerbated DVT severity in mice, as evidenced by increased thrombus weight and higher thrombosis incidence (15/15 vs 11/15 in controls, P = .0317). Higher endothelin 1 release and increased apoptosis were found in endothelial cells stimulated with supernatants of palmitate-stimulated HepG2 cells. Patients with MASH exhibited increased levels of plasma coagulation markers and delayed thrombin generation. ConclusionWe report enhanced DVT severity and hypercoagulability, both in murine and human MASH. Our model of MASH-DVT can facilitate a better understanding of the fundamental mechanisms leading to increased venous thromboembolic events in patients with MASH.

Role of Noninvasive Urinary Prothrombin Fragment 1 + 2 to Measure Blood Coagulation Indices and Dose of Acenocoumarol.

PF1 + 2 plasma levels are a crucial indicator for assessing anticoagulant action in individuals receiving anticoagulant treatment. Urine also has PF1 + 2 levels due to its molecular size. Hence, the present study aims to measure urinary prothrombin fragment 1 + 2 (uPF1 + 2) in patients taking anticoagulants in order to divulge a noninvasive surrogate marker of PT-INR of blood coagulopathy. A total of 205 people participated in the study: 104 patients on acenocoumarol (AC) and 101 healthy controls (HC). Clinical parameters, including PT-INR, urinary creatinine, etc., were measured in all subjects. To evaluate uPF1 + 2 in samples, MALDI-TOF-MS, Western blot analysis, and ELISA tests were used. The MALDI-TOF-MS results showed the presence of uPF1 + 2 in both AC and HC urine samples. The Western blot, ELISA experiment, and unpaired t test results displayed that the patients with AC had significantly increased levels of uPF1 + 2 compared to HC. A regression study showed a strong positive relation between blood-based PT-INR and uPF1 + 2. ROC validation also revealed the clinical efficacy of uPF1 + 2. For the goal to monitor anticoagulant medication, the present study highlights PF1 + 2, which describes the overall hemostatic capacity and might be utilized in addition to or instead of PT-INR.

Protein S contributes to the paradoxical increase in thrombin generation by low-dose dabigatran in the presence of thrombomodulin.

Low dose of dabigatran paradoxically increased thrombin generation through inhibition of protein C activation. Protein S is a co-factor in the activation of protein C. However, the role of protein S in the enhancement of thrombin generation has not been addressed. Firstly, we measured thrombin generation by calibrated automated thrombinography (CAT) and prothrombin fragments 1+2 (F1+2) assays. Secondly, we assessed activated protein C (APC) formation in normal or protein S-deficient plasma spiking with dabigatran. Then, protein C activation was measured. Finally, heavy chain of factor Va (FVa) and its degradation products were detected by western blot. CAT assay showed that 70-141 ng/ml dabigatran paradoxically increased thrombin generation in normal plasma. However, higher concentrations of dabigatran (283 ng/ml) suppressed the level of ETP. F1+2 assay showed the similar results. In protein S-deficient or protein C-deficient plasma, the paradoxical increase in thrombin generation was absent. Level of generated APC was to a similar extent inhibited by dabigatran in normal and protein S-deficient plasma. Low-dose dabigatran inhibited the protein S-dependent inactivation of factor Va. Protein S participated in the paradoxical enhancement of thrombin generation in normal plasma spiking with low concentrations of dabigatran. Increased thrombin generation at low dabigatran can be explained by reduced thrombin-thrombomodulin mediated APC formation and subsequent reduced FVa inactivation that is protein S-dependent.

Temporal changes in markers of coagulation and fibrinolysis in adults during extracorporeal membrane oxygenation.

Bleeding and thrombotic events (BTE) are frequent during extracorporeal membrane oxygenation (ECMO). They occur at varying timepoints and may be affected by temporal changes in coagulation and fibrinolysis. We aimed to assess various coagulation and fibrinolytic markers over time and their relationship with BTE. A single-centre prospective study was performed in 17 patients with severe respiratory failure receiving veno-venous ECMO. Blood samples were collected before and during ECMO, and around circuit decannulation. Prior to ECMO, D-Dimer, Plasmin-Antiplasmin complexes (PAP), Plasminogen-Activator Inhibitor-1 (PAI-1) and fibrinogen were elevated. There was an increase in D-Dimer and Prothrombin Fragments 1+2 (PF1+2) (729 to 1305pmol/L, p = .034) by day 1 and PAP increased by day 2 from baseline levels (median 1022 to 1797µg/L, p = .023). There was a strong positive correlation in PAP, PF1+2 and thrombin-antithrombin complexes (TAT) to D-Dimer. BTE were frequent - 18% had major extracranial haemorrhage and 24% had intracranial haemorrhage. Over time, there was a progressive elevation PAP in patients developing subsequent extracranial haemorrhage, whereas D-Dimer, PAP and PF1+2 increased after intracranial haemorrhage. There were early changes in coagulation activity during ECMO by PF1+2 followed by subsequent fibrinolysis by PAP. Changes in PAP, PF1+2 and TAT were associated with major haemorrhage.

Assessment of Coagulation Factors in Patients with Severe Rheumatic Mitral Stenosis in Sinus Rhythm with Left Atrial Appendage Inactivity

BackgroundPatients with severe mitral stenosis (MS) in normal sinus rhythm (NSR), presenting with left atrial appendage (LAA) inactivity and associated left atrial spontaneous echo contrast (LASEC) are prone to left atrium (LA) or LAA thrombus formation. But unlike for atrial fibrillation, oral anticoagulants are not commonly prescribed for this patient subset. This study aimed to compare the levels of procoagulants and fibrinogen in both local (LA) and systemic contexts between patients with severe MS in NSR vs those in healthy control subjects. MethodsThe study involved 35 patients with severe MS in NSR with LAA inactivity and LASEC who were eligible for balloon mitral valvuloplasty vs 35 healthy controls. All patients underwent transthoracic and transesophageal echocardiography to assess MS severity, LAA activity, and LASEC grade, and had blood samples analyzed for procoagulant levels. ResultsResults showed comparable baseline characteristics between groups, with most patients in the New York Heart Association II or III functional classes, and with varying LASEC grades. Patients exhibited significantly higher levels of prothrombin fragment 1 + 2 [patient vs control, 9017 pg/mL (6228.0-10,963.5) vs 1790 pg/mL (842.3-2712), P < 0.0001], thrombin-antithrombin III [patient vs control, 39 ng/mL (5.45-74.85) vs 2.80 ng/mL (1.6-6.5), P < 0.0001], plasminogen activator inhibitor-1 (patients vs controls, 26.09 ± 8.18 ng/mL vs 8.05 ± 3.53 ng/mL, P < 0.0001), and fibrinogen (3.48 ± 0.89 g/L vs 3.01 ± 0.53 g/L, P = 0.029) in the LA of patients, compared to those in control subjects. Systemic procoagulant levels also were elevated in patients, but D-dimer levels were similar between the 2 groups. ConclusionsThe findings suggest a hypercoagulable state in patients, similar to that in patients with atrial fibrillation. The study advocates for consideration of use of oral anticoagulants in these patients until LA and LAA function improves, to mitigate thrombus formation.

Establishing Expectancy Values for Fibrin Monomer in Uncomplicated Pregnancy.

Background During pregnancy, a physiological increase of molecular activation markers (MAM) of hemostasis such as prothrombin fragments 1 + 2, thrombin-antithrombin complex, and D-dimers (DD) occurs. Therefore, monitoring MAM levels during pregnancy to evaluate the risk of venous thromboembolism (VTE) may be unreliable; nevertheless, DD analysis in pregnancy is widely performed. In contrast to DD, fibrin monomer (FM) levels have been reported to remain stable during pregnancy. Objectives The main aim of this study was to define the expected range for FM levels in pregnant outpatients. In addition, we examined the impact of the individual VTE risk, as calculated by the pregnancy risk score of the Royal College of Obstetricians and Gynaecologists (RCOG), as well as that of antithrombotic treatment on FM levels. Methods A total of 342 pregnant women seen at our hemostasis unit were included throughout 350 pregnancies in 899 samples. Results Low-risk thrombophilia, but not the RCOG score itself, was found to influence all MAM levels, whereas antithrombotic treatment had only an impact on DD. For FM, a reference range could be calculated irrespective of the pregnancy term, in contrast to other MAMs, which fluctuated throughout pregnancy. Conclusions Our findings suggest a stronger impact of inherited thrombophilia on hemostasis activity during pregnancy as compared with acquired or other predisposing thrombophilic risk factors. FM levels showed a marginal increase during pregnancy in contrast to other MAM and remain a potential candidate to improve the laboratory assessment of VTE risk during pregnancy. Further prospective studies in pregnant patients with suspicion of VTE are needed.

Differences in coagulation responses to vascular injury between uninterrupted dabigatran and apixaban: A clinical prospective randomized study

BackgroundThe coagulation response during vascular injury with uninterrupted administration of direct oral anticoagulants has not been elucidated. ObjectiveOur aim was to evaluate differences in coagulation responses after vascular injury between uninterrupted direct thrombin inhibitor and direct factor Xa inhibitor recipients. MethodsPatients scheduled for catheter ablation for atrial fibrillation were randomly assigned to receive dabigatran or apixaban in this prospective, randomized, comparative, parallel-group study. Venous blood was collected 3 times: 180 minutes after taking the anticoagulant on the day before the procedure, before vascular punctures of the ablation procedure, and 10–15 minutes after the start of vascular punctures. ResultsForty-two patients were enrolled. The prothrombin fragment 1+2 level, the primary end point, was much larger after vascular puncture in the uninterrupted dabigatran recipients (median, 83 pmol/L; interquartile range, 56–133 pmol/L) than in the uninterrupted apixaban recipients (median, 1 pmol/L; interquartile range, −3 to 19 pmol/L; P < .001). Antithrombin levels decreased after vascular puncture in dabigatran recipients, and both protein C and antithrombin levels decreased after vascular puncture in apixaban recipients. ConclusionUnlike uninterrupted apixaban, uninterrupted dabigatran does not inhibit thrombin generation in response to vascular injury.

Impact of different energy sources on coagulation biomarkers and silent cerebral events in balloon-based ablation for atrial fibrillation

BackgroundDifferent energy sources of balloon-based ablation for pulmonary vein isolation (PVI) cause different kinds of endothelial damage and coagulation responses associated with thromboembolic risk. ObjectivesTo compare the impact of different balloon-based ablation, cryo-balloon ablation (CBA) and laser balloon ablation (LBA), on coagulation/fibrinolysis biomarkers and silent cerebral events (SCEs) in paroxysmal atrial fibrillation (PAF). MethodsPAF patients who underwent PVI using either CBA (n=52) or LBA (n=53) without radiofrequency touch-up ablation were eligible. Time-course (day-0 [before ablation], day-1, day-2, and day-28) of myocardial enzymes and inflammatory and coagulation/fibrinolysis biomarkers was evaluated during the perioperative period. Brain MRI was performed within 2 days after the procedure to evaluate SCEs. ResultsThere was no difference in patient characteristics between CBA and LBA.CBA had greater myocardial injury (troponin-I and creatine kinase MB) and lower inflammatory reaction (WBC and neutrophil/lymphocyte ratio) than LBA. The coagulation biomarkers maximally increased by day-2 and then decreased in both groups. In day-28, the serum prothrombin fragment 1+2 and D-dimer levels in LBA were significantly higher than the values in CBA. The fibrinolysis biomarker (plasmin-α2 plasmin inhibitor complex) did not increase after the procedure in either group. The incidence of SCEs was comparable between CBA and LBA (11% vs. 15%, p=0.591). No thromboembolic event was observed. ConclusionCBA and LBA had different effects on myocardial injury, inflammatory reaction, and coagulation activity but did not affect the incidence of thromboembolic events. LBA had significantly higher coagulation activity in day-28 and may require more careful post-procedural anticoagulation than CBA.

Daytime plasma cortisol and cortisol response to dexamethasone suppression are associated with a prothrombotic state in hypertension.

A prothrombotic state was demonstrated in patients with Cushing's syndrome and is involved in the development and progression of cardiovascular and renal damage in hypertensive patients. This study was designed to examine the relationships between cortisol secretion and the hemostatic and fibrinolytic systems in hypertension. In 149 middle-aged, nondiabetic, essential hypertensive patients free of cardiovascular and renal complications, we measured hemostatic markers that express the spontaneous activation of the coagulation and fibrinolytic systems and assessed daily cortisol levels (8 AM, 3 PM, 12 AM; area under the curve, AUC-cortisol) together with the cortisol response to dexamethasone overnight suppression (DST-cortisol). Plasma levels of D-dimer (D-dim), prothrombin fragment 1+2 (F1+2), and von Willebrand factor (vWF) were progressively and significantly higher across tertiles of AUC-cortisol and DST-cortisol, whereas no differences were observed in fibrinogen, tissue plasminogen activator, plasminogen activator inhibitor-1, antithrombin III, protein C, and protein S. D-dim, F1+2, and vWF were significantly and directly correlated with age and both AUC-cortisol and DST-cortisol. Multivariate regression analysis showed that both AUC-cortisol and DST-cortisol were related to plasma D-dim, F1+2, and vWF independently of age, body mass index, blood pressure, and renal function. Greater daily cortisol profile and cortisol response to overnight suppression are independently associated with a prothrombotic state in hypertensive patients and might contribute to the development of organ damage and higher risk of cardiovascular complications.

D-dimer and fibrinogen indicate ischemic risk in patients with atrial fibrillation after percutaneous coronary intervention

BackgroundThis study aimed to evaluate the association of antiphospholipid antibodies (aPL) and conventional markers of coagulation with ischemic and bleeding risk in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI).MethodsIn this prospective two-center observational cohort study, patients with AF and an indication for oral anticoagulation (OAC) were enrolled after PCI. Blood was drawn on day 1–3 after PCI. Dilute Russell’s viper venom time was used to determine lupus anticoagulant (LA) in OAC-free plasma. Anti-cardiolipin (aCL) IgG, IgM, and anti-β2-Glycoprotein 1 (aβ2GP1) IgG were analyzed by enzyme-linked immunosorbent assay (ELISA). Fibrinogen (FIB), d-dimer, and prothrombin fragment 1 and 2 (PF 1 + 2) were measured in citrated plasma. The primary ischemic outcome was time to major adverse cardiovascular events (MACE; death, myocardial infarction, or stroke) assessed at 6 months. Bleeding was defined according to International Society on Thrombosis and Haemostasis.Results158 patients were enrolled between May 2020 and May 2021 on day 1–3 after PCI. The median age was 78 years (interquartile range [IQR] 72–82), 111 (70%) were male, and 39 (25%) presented with acute coronary syndrome. D-dimer was elevated in 74 (47%) patients, FIB was increased in 40 (25%) and PF1 + 2 in 68 (43%) patients. 32 (20%) patients had ≥ 1 antiphospholipid antibody elevated (aPL; LA: 19 [12%], aCL: 14 [9%], aβ2GP1: 2 [1%]). The presence of aPL was neither significantly associated with MACE (HR 1.46, 95% CI [0.39–5.49], p = 0.579), nor bleeding (HR 1.07 [0.30–3.84], p = 0.917). Elevated d-dimer was significantly associated with higher risk for MACE (HR 5.06 [1.09–23.41], p = 0.038) and major bleeding (HR 7.04 [1.58–31.47], p = 0.011). Elevated D-dimer increased the predictive capacity of HAS-BLED for major bleedings (HAS-BLED: AUC 0.71 [0.60–0.83] vs. HAS-BLED + d-dimer: AUC 0.79 [0.70–0.88]; p = 0.025). Increased levels of FIB were associated with higher risk for MACE (HR 3.65 [1.11–11.96], p = 0.033).ConclusionBiomarkers of coagulation might be suitable to assess ischemic and bleeding risk in patients with AF following PCI.

Abstract 155: Plasma Kallikrein Is A Key Driver Of Basal Activation Of Coagulation Under Conditions Of C1 Inhibitor Deficiency

C1 inhibitor (C1INH) functions as a key endogenous inhibitor of contact pathway coagulation factors XII, XI and plasma kallikrein (PKa). Patients with a congenital deficiency in C1INH suffer from a rare swelling disorder called hereditary angioedema (HAE) caused by excess bradykinin generation. Patients with HAE also have elevated circulating levels of markers of activation of coagulation and an increased risk of venous thromboembolism, phenotypes recapitulated in C1INH-deficient mice. We sought to evaluate the molecular mechanism by which C1INH deficiency leads to increased basal activation of coagulation and venous thrombosis. We hypothesized that PKa serves as a key driver of activation of coagulation in humans and mice with congenital C1INH deficiency. Patients with C1INH deficiency-associated HAE were treated with the PKa inhibitor lanadelumab with plasma samples collected before and after treatment. Plasma levels of coagulation markers and contact pathway-initiated thrombin generation were determined. C1INH-deficient mice were treated with the PKa inhibitor avoralstat, the FXIIa inhibitor garadacimab, FXII small interfering RNAs, FXI antisense oligonucleotides, the anti-tissue factor antibody 1H1 or appropriate controls and plasma coagulation markers were measured. Treatment of HAE patients with the PKa inhibitor lanadelumab significantly reduced plasma levels of prothrombin fragment 1.2, thrombin antithrombin (TAT) complexes and D-dimer at 6 months after treatment initiation (P&lt;0.05). Interestingly, landalumab had no significant effect on contact pathway-initiated thrombin generation. In experiments with C1INH deficient mice, TAT complexes were significantly reduced by PKa inhibition (P&lt;0.01) but not by inhibition of FXIIa or FXIa. Interestingly, tissue factor inhibition also significantly reduced plasma TAT complexes (P&lt;0.01). This data suggests that under conditions of C1INH deficiency PKa potentiates activation of coagulation through a non-canonical pathway involving tissue factor. These findings demonstrate that C1INH is a physiologically relevant anticoagulant with C1INH deficiency resulting in enhanced kallikrein-mediated activation of basal coagulation.

Are Gamers Prone to eThrombosis during Long Gaming Sessions?

During the last two decades, several cases of venous thrombosis (VTE) after a prolonged period at a computer have been described, denominated as "eThrombosis". Video gaming on a computer has become very popular and can be a social activity where several players gather to play against each other or in a virtual environment for several days ("LAN (i.e., Local Area Network) parties") where the participants are sedentary and consuming calorie-rich food items. The aim of this study was to investigate potential coagulation activation during a 42 h LAN party. Nine male gamers volunteered for the LAN party. Citrated blood was sampled before and every 6 h, and plasma was analyzed for thrombin generation, thrombin-antithrombin complexes (TAT), prothrombin fragment 1 + 2 (F1 + 2), and D-dimer. Thrombin generation increased slightly but not significantly during the LAN party, whereas the coagulation activation markers were unchanged. These results do not indicate that the coagulation system is activated significantly during 42 h of gaming with minimal physical activity. Although increased activity cannot be excluded, it does not directly indicate a risk of VTE in general.

Current Clinical Practice of Laboratory Testing of the Hemostasis and Coagulation System in Patients with Sepsis: A Nationwide Observational Study in Japan.

The clinical benefit of hemostasis molecular indicators such as thrombin-antithrombin complex (TAT), soluble fibrin (SF), and prothrombin fragment 1 + 2 (F1+2) for the diagnosis of disseminated intravascular coagulation (DIC) is reported. Recently, novel DIC diagnostic criteria that adopt them were proposed in Japan. Despite the theoretical understanding of their function, the practical use of these markers remains unclear. The present study aimed to provide a descriptive overview of current clinical practice regarding the measurement of hemostasis markers in sepsis management in Japan. This retrospective observational analysis used the Japanese Diagnosis Procedure Combination inpatient database containing data from more than 1500 acute-care hospitals in Japan. We identified adult patients hospitalized for sepsis between April 2018 and March 2021. Descriptive statistics for measuring several hemostasis laboratory markers were summarized using patient disease characteristics, hospital characteristic, and geographical location. This study included 153,474 adult sepsis patients. Crude in-hospital mortality was 30.0%. Frequency of measurement of fibrinogen, fibrin degradation products (FDP), and D-dimer in sepsis patients on admission was 43.2%, 36.1%, and 46.4%, respectively. Novel and specific hemostasis molecular markers such as TAT, SF, and F1+2 were seldom measured (1.9%, 1.7%, and 0.02%, respectively). Hemostasis molecular markers were more frequently measured with progression of thrombocytopenia. Measurement of these clinically favorite hemostasis markers was influenced not only by disease characteristics but also hospital characteristic or geographical location. Hemostasis molecular markers such as TAT, SF, and F1+2 were rarely measured in clinical settings. Although adopted by several DIC scoring systems, neither fibrinogen, FDP, nor D-dimer was routinely measured.

Acute and subacute effects of strenuous exercise on platelet aggregation, coagulation and fibrinolysis in patients with stable coronary artery disease

IntroductionStrenuous exercise may occasionally cause coronary thrombosis with myocardial infarction and sudden cardiac death. Materials and methodsPatients with stable coronary artery disease (CAD) (n = 164) and healthy individuals (n = 25) performed strenuous exercise on a bicycle ergometer. Blood was drawn at baseline, immediately after exercise and 2 h later. Platelet aggregation was measured with Multiplate® Analyzer. Thrombin generation was determined using a thrombogram and by measuring prothrombin fragment 1 + 2 (F1 + 2). A clot lysis assay was used to investigate fibrinolysis. ResultsFrom baseline to immediately after exercise, thrombin receptor activating peptide (TRAP)-induced platelet aggregation increased in CAD patients (Δ77 AU × min, 95 % confidence interval (CI): 46;107) and in healthy individuals (Δ153 AU × min, 95%CI: 75;232). Endogenous thrombin potential (ETP) was unaffected by exercise, whilst F1 + 2 increased (Δ17%, 95%CI: 11;24) in CAD patients. Fibrin clot lysis time increased by 9 % (95%CI: 1–17) in CAD patients and by 26 % (95%CI: 8;45) in healthy individuals. When comparing baseline to 2 h post-exercise, TRAP-induced platelet aggregation remained slightly elevated in both CAD patients (Δ53 AU × min, 95%CI: 22;84) and healthy individuals (Δ140 AU × min, 95%CI: 62;219). In contrast, ETP and F1 + 2 decreased in CAD patients (Δ-6 %, 95%CI: −10;-1 and Δ-8 %, 95%CI: -14;-2). Moreover, clot lysis time decreased (Δ-19 %, 95%CI: −27;-11) in patients with CAD and returned to baseline in healthy individuals. All p-values were <0.05. ConclusionsPlatelet aggregation and F1 + 2 were substantially elevated immediately after exercise in CAD patients, indicating a pro-thrombotic state. After 2 h of recovery, they exhibited a markedly increase in fibrinolysis. Similar results were observed in healthy individuals.