Levels Of Prothrombin Fragment Research Articles

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.

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.

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.

Enhanced in vivo and ex vivo thrombin generation after lower-leg trauma, but not after knee arthroscopy

BackgroundThere is room for improvement of prevention of venous thromboembolism (VTE) after lower-leg cast application or knee arthroscopy. Information about the mechanism of clot formation in these patients may be useful to identify new prophylaxis targets. We aimed to study the effect of 1) lower-leg injury and 2) knee arthroscopy on thrombin generation.MethodsA cross-sectional study was conducted using plasma samples of POT-(K)CAST trials to measure ex vivo thrombin generation (Calibrated Automated Thrombography [CAT]) and plasma levels of prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin (TAT), fibrinopeptide A (FPA). Plasma was obtained shortly after lower-leg trauma or before and after (< 4 h) knee arthroscopy. Participants were randomly selected from those who did not develop VTE. For aim 1, samples of 88 patients with lower-leg injury were compared with 89 control samples (i.e., preoperative samples of arthroscopy patients). Linear regression was used to obtain mean differences (or ratios if ln-retransformed because of skewedness) adjusted for age, sex, body mass index, comorbidities. For aim 2, pre- and postoperative samples of 85 arthroscopy patients were compared, for which mean changes were obtained.ResultsIn patients with lower-leg injury (aim 1), endogenous thrombin potential, thrombin peak, velocity index, FPA and TAT were increased as compared with controls. In arthroscopy patients (aim 2), pre- and postoperative levels were similar for all parameters.ConclusionLower-leg trauma increases thrombin generation both ex vivo and in vivo, in contrast to knee arthroscopy. This may imply that the pathogenesis of VTE is different in both situations.

C1 inhibitor deficiency enhances contact pathway–mediated activation of coagulation and venous thrombosis

AbstractC1 inhibitor (C1INH) is a multifunctional serine protease inhibitor that functions as a major negative regulator of several biological pathways, including the contact pathway of blood coagulation. In humans, congenital C1INH deficiency results in a rare episodic bradykinin-mediated swelling disorder called hereditary angioedema (HAE). Patients with C1INH deficiency–associated HAE (C1INH-HAE) have increased circulating markers of activation of coagulation. Furthermore, we recently reported that patients with C1INH-HAE had a moderate but significant increased risk of venous thromboembolism. To further investigate the impact of C1INH deficiency on activation of coagulation and thrombosis, we conducted studies using patient samples and mouse models. Plasmas from patients with C1INH-HAE had significantly increased contact pathway–mediated thrombin generation. C1INH-deficient mice, which have been used as a model of C1INH-HAE, had significantly increased baseline circulating levels of prothrombin fragment 1+2 and thrombin-antithrombin complexes. In addition, whole blood from C1INH-deficient mice supported significantly increased contact pathway–mediated thrombin generation. Importantly, C1INH-deficient mice exhibited significantly enhanced venous, but not arterial, thrombus formation. Furthermore, purified human C1INH normalized contact pathway–mediated thrombin generation and venous thrombosis in C1INH-deficient mice. These findings highlight a key role for endogenous C1INH as a negative regulator of contact pathway–mediated coagulation in humans and mice. Further, this work identifies endogenous C1INH as an important negative regulator of venous thrombus formation in mice, complementing the phenotype associated with C1INH-HAE.

Combined oral contraceptives containing estradiol valerate vs ethinylestradiol on coagulation: A randomized clinical trial.

Contraceptives containing ethinylestradiol (EE) induce changes in the coagulation system and are associated with a risk of venous thromboembolism. However, studies comparing the effects of combined oral contraceptives containing EE and low-potency estrogens (ie, estradiol [E2 ] and estradiol valerate [EV]) on coagulation biomarkers are limited. This study represents secondary outcomes of a randomized trial comparing combined oral contraceptives containing EV + dienogest (DNG), EE + DNG, and DNG alone on selected coagulation biomarkers. We could compare the specific effects of the different estrogen components owing to the inclusion of preparations containing the same progestin. We enrolled 59 healthy, 18- to 35-year-old, non-smoking women, of whom three discontinued. The participants were randomly allocated to 9 weeks of continuous treatment with EV 2mg + DNG 2-3mg (n= 20), EE 0.03 mg + DNG 2mg (n= 20), or DNG 2mg (n= 19). Blood samples were collected at baseline and after 9 weeks. We assessed coagulation in vitro by thrombin generation using the Calibrated Automated Thrombogram. Thrombin generation was evaluated by lag time, time to thrombin peak, thrombin peak, and endogenous thrombin potential in response to tissue factor (1pm). In vivo coagulation assessment was based on levels of prothrombin fragment 1+2 (F1 +2) (thrombin generation) and D-dimer (fibrin turnover). NCT02352090. Lag time and time to thrombin peak remained unaltered after exposure to EV + DNG, whereas EE + DNG shortened both lag time (mean percentage change -24%, 95% confidence interval [CI] -32% to -15%; p< 0.01) and time to thrombin peak (-26%, 95% CI -37% to -16%; p< 0.01). EV + DNG induced lower thrombin peak and endogenous thrombin potential than EE + DNG (peak; +45%, 95% CI 22%-67% vs +147%,95% CI 96%-198%; p< 0.01, and endogenous thrombin potential; +26%, 95% CI 15%-38% vs +64%, 95% CI 51%-76%; p< 0.01). Median F1 +2 levels remained unchanged with EV + DNG (p= 0.22) but increased within normal ranges with EE + DNG (from 152 pmol/L, 95% CI 127-206]pmol/L to 194 pmol/L, 95% CI 149-250 pmol/L, p= 0.04). The within-group change in D-dimer levels was not significant in any of the groups. DNG alone did not affect these biomarkers. Both in vitro and in vivo thrombin generation was lower after exposure to EV + DNG compared with EE + DNG. The lower thrombin generation measures after treatment with EV + DNG indicate less enhancement of coagulation potential and suggest that EV may be favorable to EE as a component of combined oral contraceptives.

Both UFH and NAH alleviate shedding of endothelial glycocalyx and coagulopathy in LPS-induced sepsis.

Sepsis commonly progresses to disseminated intravascular coagulation and induces the activation of heparanase (HPA) and the shedding of endothelial glycocalyx constituents, including syndecan-1 (SDC-1) and heparan sulphate (HS). However, the degradation of glycocalyx and its association with coagulation disorders remains undetermined. The present study aimed to evaluate the effect of unfractionated heparin (UFH) and N-acetylheparin (NAH), which is a non-anticoagulant heparin derivative, on endothelial glycocalyx and coagulation function in a lipopolysaccharide (LPS)-induced sepsis rat model, and to compare the differences observed in coagulation function between UFH and NAH. Experimental rats were randomly assigned to four groups: Control; LPS; UFH + LPS; and NAH + LPS. Rats were administered UFH or NAH and subsequently, ~1 min later, administered LPS (10 mg/kg; intravenous). The blood and lung tissues of rats were collected 0.5, 2 and 6 h after LPS injection, and were used for subsequent analysis. The results demonstrated that HPA activity and SDC-1 and HS levels increased, and this increase was associated with inflammatory cytokines and coagulation/fibrinolysis markers in the sepsis rat model. Histopathological examination was performed, and the lung injury score and lung wet/dry ratio indicated that UFH and NAH also significantly improved lung tissue injury. The results of the ELISA analysis demonstrated that UFH and NAH treatment: i) significantly decreased the levels of inflammatory cytokines including tumor necrosis factor-α and interleukin-6; ii) inhibited HPA activity and protected the integrity of the glycocalyx, which was identified by decreased HS and SDC-1 levels; and iii) decreased the levels of prothrombin fragment 1+2, thrombin-antithrombin complex, and plasminogen activator inhibitor-1 and increased the levels of fibrinogen and antithrombin-III. Preconditioning with UFH decreased the plasma activated partial thromboplastin time. These results indicated that UFH and NAH may alleviate sepsis-induced coagulopathy, and this effect may have been due to an inhibition of HPA activity and decrease in the shedding of the endothelial glycocalyx.

Potential Anti-Thrombotic Effect without Accompanying Hemorrhage with Fostamatinib Use in Patients with Immune Thrombocytopenia

Potential Anti-Thrombotic Effect without Accompanying Hemorrhage with Fostamatinib Use in Patients with Immune Thrombocytopenia

Risk factors for deep vein thrombosis of lower extremities in Sudanese women.

AimIn this study, we aimed to analyze the genetic and acquired risk factors for deep vein thrombosis (DVT) of the lower extremities among Sudanese women.MethodsA total of 136 women were enrolled in the study, including 75 DVT patients and 61 healthy controls. Demographic and clinical data were collected using a specific questionnaire. Citrated blood samples of patients and controls were used for coagulation assays, and DNAs isolated from EDTA-blood samples were used for the detection of Factor V Leiden and prothrombin G20210A mutations using multiplex polymerase chain reaction-restriction fragment length polymorphism analysis.ResultsBoth gene mutations were found to be absent from all 136 subjects, and therefore did not account for the incidence of DVT in Sudanese women. Of the 75 DVTs, 70 (93.3%) were localized in the left leg and 5 (6.7%) in the right leg. Additionally, 84% of the DVTs were proximal and 16% were distal. Among the 75 patients, 22 (29.33%) were postpartum, 7 (9.33%) were pregnant, and 46 (61.33%) were nonpregnant. Levels of prothrombin fragment 1+2, prothrombin time, activated partial thromboplastin time, and D-dimer were significantly higher in DVT patients than in healthy controls (P<0.0001).ConclusionRisk factors that most significantly affected patients in the 18–45 years age group were pregnancy and oral contraceptive usage, whereas those that most significantly affected patients in the 66–90 years age group were immobility, heart disease, and history of DVT.

EVALUATION OF DYSFUNCTION IN BLOOD COAGULATION IN CHILDREN WITH URTICARIA

Recently, an association between coagulation dysfunction and the pathology of urticaria has been reported, but research in children is scarce. We measured levels of prothrombin fragments 1+2 (PTF1+2), fibrin degradation product (FDP), D-dimer, and mean platelet volume (MPV) in 32 children with urticaria. The study cohort comprised 18 cases of chronic and active urticaria, 7 cases of chronic and inactive urticaria, and 7 cases of acute urticaria. PTF1+2 levels in the chronic and active urticaria group were higher than those in the chronic and inactive urticaria group (p<0.01). PTF1+2 levels in the acute urticaria group were higher than those in the chronic and inactive group (p<0.05). No significant difference was observed in the levels of FDP, D-dimer, and MPV among the three groups of the patients. Levels of PTF1+2, FDP, and D-dimer decreased as symptoms improved. Plasma levels of PTF1+2 may be useful for assessment of the activity of urticaria.

The effect of adjuvant chemotherapy on plasma TAT and F 1+2 levels in patients with breast cancer.

Increased thromboembolic disorders and chemotherapy-induced thromboembolic events are well known phenomena in patients with breast cancer. Antithrombin III (AT III) inactivates thrombin, resulting in increased thrombin-antithrombin (TAT) levels. Activated factor X cleaves prothrombin and thrombin, resulting in increased levels of prothrombin fragment 1+2 (F 1+2). Increased TAT and F 1+2 levels show coagulation activation. The aim of this study was to examine plasma levels of TAT and F 1+2 and the effect of anthracycline-based chemotherapy on plasma TAT and F 1+2 in patients with operable breast cancer. Seventy patients and 30 age-matched healthy controls were enrolled. Levels of TAT and F 1+2 were investigated before and after adjuvant chemotherapy. Basal levels (pre-chemotherapy) of TAT and F 1+2 in patients were compared with those in healthy controls and patient levels after 3 cycles of chemotherapy. Levels of TAT and F 1+2 were determined using the ELISA method. TAT and d-dimer levels were significantly higher in patients, (P: 0.02 and P<0.001, respectively). Post-chemotherapy F 1+2 levels were higher than basal levels (P: 0.02). F 1+2 levels were higher in patients, although the difference was not statistically significant (P: 0.52). There was no difference between basal and post-chemotherapy TAT levels. In conclusion, while higher post-chemotherapy F 1+2 levels suggest that the cumulative effect of chemotherapy increases the risk of thrombosis, TAT and d-dimer levels indicate that the effect of the cancer further increases the risk of thrombosis in patients with operable breast cancer.

Fibrin clot properties and haemostatic function in men and women with type 1 diabetes.

The increased risk of vascular complications in type 1 diabetes may in part be explained by changes in haemostatic function. In the present study, we investigated the fibrin clot properties in patients with type 1 diabetes in relation to sex and microvascular complications. The study included 236 patients (107 women) aged between 20-70 years and without any history of cardiovascular disease. Fibrin clot properties, assessed by determination of the permeability coefficient (Ks) and turbidimetric clotting and lysis assays, did not differ between men and women. Compared with men, women had worse glycaemic control as well as higher levels of prothrombin fragment 1+2 and peak thrombin generation in vitro, indicating increased thrombin generation both in vivo and in vitro. Subgroup analyses of patients younger than 30 years revealed less permeable fibrin clots and prolonged lysis time in females compared with age-matched men. Patients with microvascular complications had higher fibrinogen concentrations and denser and less permeable fibrin clots. Thus, we conclude that in vitro fibrin clot properties in patients with type 1 diabetes without cardiovascular disease are not different between the sexes, but associate with prevalence of microvascular complications. Tighter fibrin clot formation in younger women, as suggested by our results, may affect their future cardiovascular risk and should be investigated in a larger population.

Short-term venous stasis induces fibrinolytic activation but not thrombin formation.

Venous stasis is a well-known risk factor for the development of venous thromboembolism. It is likely that stasis increases the risk of thrombosis by inducing hypercoagulability via the hypoxic procoagulant activation of endothelial and mononuclear cells and the accumulation of activated clotting factors. However, increased rates of thrombin formation have not been demonstrated in response to venous stasis in vivo. In this study, we used the venous occlusion (VO) test to determine, if stasis triggers thrombin formation in healthy individuals (n=25) and patients with additional thrombotic risk factors, such as inherited thrombophilia (n=19) and symptomatic atherosclerosis (n=15). Thrombin formation was monitored by measuring plasma levels of free thrombin using a highly sensitive oligonucleotide enzyme capture assay (OECA) in addition to the plasma levels of prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin-complexes (TAT). The plasma levels of activated protein C (APC) were additionally measured using an APC-OECA. VO induced a significant (p<0.05) increase in the levels of tissue-type plasminogen activator and plasmin-α2-antiplasmin-complexes. In all three cohorts, the majority of samples obtained during VO showed no quantifiable thrombin or APC levels. Consistent with these findings F1+2 and TAT did not change. We conclude that short-term venous stasis induces a profibrinolytic response due to the activation of endothelial cells, but not a prothrombotic response, even in the presence of additional thrombophilic risk factors. Furthermore, our results support the hypothesis that the stasis-induced profibrinolytic activation of endothelial cells occurs independently from thrombin formation.

Clinical impact of factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations among sickle cell disease patients of Central India

It is known that patients with sickle cell disease (SCD) present activation of the blood coagulation and fibrinolytic systems, especially during vaso-occlusive crises and also during the steady state of the disease. We determined whether the presence of the factor prothrombin gene G20210A variant, factor V gene G1691A mutation (factor V Leiden), and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms may be risk factors for vascular complications in individuals with SCD. The study involved 150 patients with sickle cell anemia and 150 healthy controls of Central India. Genotyping of three thrombophilic mutations was carried out by PCR-RFLP methods using MnlI, Hind III, and Hinf I, respectively, for factor V Leiden, prothrombin, and MTHFR mutations. Patients with SCD had significantly higher prevalence of mutant variants of MTHFR gene (28.0% heterozygotes and 14.6% homozygotes) and FVL gene (14.6% heterozygotes) as compared to normal/control individuals, but complete absence of mutant variants of prothrombin gene. The patients with SCD having mutant variants of MTHFR and FVL genes showed higher incidence of pain in chest, abdomen, and bone joints along with early age of onset of clinical manifestations as well as frequent dependence on blood transfusion than those patients with SCD having wild variants of these thrombotic genes. As compared to control subjects, SCD individuals having mutant variants of FVL and MTHFR genes had significant association with higher levels of prothrombin fragment (F1+2), D-dimer, thrombin-antithrombin (TAT), and lower level of protein C. MTHFR C677T and FVL G1691A polymorphisms may be risk factors for increased vascular complications in patient with SCD.

Prothrombotic markers in patients with acute myocardial infarction and left ventricular thrombus formation treated with pci and dual antiplatelet therapy

BackgroundThe aim of the present study was to compare circulating levels of selected prothrombotic markers in patients suffering acute myocardial infarction (AMI) with and without left ventricular (LV) thrombus.MethodsOne hundred patients with AMI treated with PCI on the LAD and dual antiplatelet therapy were included. LV thrombus formation was detected by echocardiography and/or MRI in 15 patients. Fasting blood samples were drawn 4–5 days (baseline), 6–7 days, 8–9 days, 2–3 weeks and 3 months after the AMI for determination of haemostatic markers.ResultsWe found higher levels of soluble tissue factor (TF) and D-dimer in the LV thrombus group 4–5 days, 8–9 days and 3 months (only TF) after the AMI compared to the patients without thrombus formation (p<0.05). Patients with TF in the upper quartile at baseline had significantly higher risk for LV thrombus (OR 4.2; 95% CI 1.2 -14.5; p=0.02, adjusted for infarct size).The levels of prothrombin fragment 1+2 (F1+2) and endogenous thrombin potential (ETP) were significantly lower in the thrombus group after 8–9 days (only ETP), 2–3 weeks and 3 months. The levels of plasminogen activator inhibitor 1 activity and tissue plasminogen activator antigen did not differ between the groups.ConclusionIn the acute phase of AMI, we found higher levels of TF and D-dimer in the LV thrombus group, indicating hypercoagulability of possible importance for the generation of mural thrombus. Lower levels of F1+2, ETP and D-dimer in the thrombus group late during follow-up are probably induced by the initiated anticoagulation therapy.

A randomised study of dabigatran in elective percutaneous coronary intervention in stable coronary artery disease patients

Patients receiving long-term anticoagulant treatment with dabigatran may need to undergo a percutaneous coronary intervention (PCI). We studied markers of coagulation activation during elective PCI in patients using dabigatran in order to investigate whether coagulation activation upon balloon inflation and stenting is suppressed by dabigatran without additional heparin treatment. This phase IIa, exploratory, multicentre, randomised, open-label study included 50 stable patients having an elective PCI. Patients on standard dual antiplatelet therapy (DAPT) were randomised (2:2:1) to either pre-procedural dabigatran 110 mg BID (n=19) or 150 mg BID (n=21), as compared to standard intraprocedural unfractionated heparin (UFH) (n=10). Following PCI, a significant increase in the levels of prothrombin fragment 1+2 (F1+2) in the combined dabigatran group was observed compared to the level just before the start of PCI (159.1 [1.4] pmol/l; geometric mean [gSD]). Levels at 0.5, 1.0, 1.5 and 2 hrs after the start of PCI ranged from 193.5 (1.4) to 270.6 pmol/l (1.7); (p-value for paired analysis=0.015, 0.022, 0.2342, 0.0379, respectively). Also, thrombin-antithrombin (TAT) complexes were increased significantly in the combined dabigatran group compared to pre-PCI levels (4.2 [2.2] ug/l). Levels ranged from 5.2 (2.5) to 8.5 (2.3) (p=0.0497, 0.0343, 0.005 and 0.1628, respectively). In contrast, in the control group of patients treated with UFH, no increase was observed in F1+2 and TAT complexes during PCI. Five out of 40 (12.5%) patients required bail-out anticoagulation in the dabigatran group, of whom four experienced a procedural myocardial infarction (MI), versus one out of 10 in the UFH group, who had a stent thrombosis without MI prior to the study-PCI. One minor access-site bleeding occurred in the dabigatran group. Dabigatran treatment (110 mg or 150 mg BID) may not provide sufficient anticoagulation during PCI. EudraCT. No: 2007-007536-25.

Coagulation and fibrinolysis abnormalities in familial amyloid polyneuropathy

Objective: Familial amyloid polyneuropathy (FAP) is an autosomal dominant form of hereditary amyloidosis. Several studies reported coagulation factor X deficiency and excessive fibrinolysis in immunoglobulin light chain amyloidosis. However, few have investigated coagulation and fibrinolysis in FAP. The objective of this study was to determine abnormalities in plasma biomarkers of coagulation and fibrinolysis in FAP. Methods: We prospectively recruited eight FAP patients with transthyretin mutations and ten age-matched control patients with other neuropathies in our university. We examined plasma biomarkers of coagulation and fibrinolysis including prothrombin time, activated partial thromboplastin time, fibrinogen, fibrin/fibrinogen degradation products, D-dimer, α2-antiplasmin, antithrombin, plasminogen, thrombin-antithrombin complex, plasmin-α2-antiplasmin complex, prothrombin fragment 1+2, and coagulation factor X. The Mann–Whitney U test was performed for statistical comparisons between FAP and control groups. Results: FAP patients exhibited significantly decreased levels of coagulation factor X, plasminogen and α2-antiplasmin, and significantly increased levels of prothrombin fragment 1+2 compared to control patients. Conclusion: Our results indicate abnormalities of coagulation and fibrinolysis in FAP patients.

Inflammatory and thrombotic markers in patients with ST-elevation myocardial infarction treated with thrombolysis and early PCI: A NORDISTEMI substudy

IntroductionBoth pharmacological and invasive treatment might influence the inflammatory and pro-thrombotic responses observed in acute ST-elevation myocardial infarction (STEMI). We aimed to study whether circulating levels of inflammatory and pro-thrombotic markers differ in STEMI patients treated with early angioplasty compared to standard therapy following thrombolysis. Furthermore, we wanted to study if levels of markers were related to infarct size. Materials and MethodsThis was a substudy of the NORwegian study on DIstrict treatment of ST-Elevation Myocardial Infarction (NORDISTEMI), in which STEMI patients treated with thrombolysis were randomized to early invasive or standard therapy. Fasting blood samples were collected in the morning 3days and 3months after onset of STEMI. Commercially available ELISA methods were used for determination of inflammatory and pro-thrombotic markers. Infarct size was assessed by SPECT after 3months. Results246 patients were included in this substudy. At 3days, levels of prothrombin fragment 1+2 and D-dimer were higher in the early invasive compared to the standard treatment group, whereas levels of soluble CD40 ligand were lower (p<0.01 for all). No other differences between groups were found in any of the measured markers. Significant, although weak correlations were found between Day 3 levels of C-reactive protein, interleukin-6, prothrombin fragment 1+2 and D-dimer, and infarct size assessed by SPECT after 3months. ConclusionsAn early invasive strategy following thrombolysis for STEMI was associated with higher subacute levels of D-dimer and prothrombin fragment 1+2, and lower levels of soluble CD40 ligand than standard treatment. Further studies are needed to establish the relation between these changes and clinical outcome.The NORDISTEMI was registered at www.clinicaltrials.gov, NCT00161005.

Beyond Hyperglycemia in Diabetes: Role of Statin Treatment on Thrombogenesis Triggered by Inflammation

Type 2 diabetes mellitus (T2D) constitutes a growing global public health problem and its prevalence is estimated to increase during the next decades, especially in the developing countries. To date, 15 % of the whole population is considered at high risk to develop T2D [1]. T2D is associated with a decrease of health-related quality of life and overall life expectancy, mainly due to an increased risk for cardiovascular disorders. Indeed, T2D is commonly associated with both microvascular and macrovascular complications [2]. Macrovascular complications manifest themselves as accelerated atherosclerosis, clinically resulting in premature coronary artery disease, increased risk of cerebrovascular disease, and severe peripheral vascular disease [2]. Patients with T2D have a a twoto four-fold increase in the risk of coronary artery disease (CAD) and patients with DM but without previous myocardial infarction (MI) carry the same level of risk for subsequent acute coronary events as non-diabetic patients with previous MI [3, 4] so that T2D has been defined a CAD equivalent. T2D is associated with a prothrombotic state characterized by a number of changes in thrombotic and fibrinolytic coagulation factor level/activity, which together increase the risk of thrombus formation. Both glucose and insulin seem to play a role in the pathogenesis of this prothrombotic state [5]. In vitro induced thrombin generation is increased in platelet-rich plasma from diabetics compared with that from healthy subjects and a significant elevation of thrombin levels can be demonstrated in T2D patients in poor metabolic control when compared with well controlled patients [6].Moreover, a significant correlation can be observed between improved glycemic control and blood thrombogenicity, as reflected by a reduction in ex-vivo thrombus formation in a Badimon perfusion chamber [7]. Improved glycemic control is the only significant predictor of a decrease in blood thrombogenicity, irrespective of treatment allocation [7]. Enhanced levels of prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin complexes (TAT) have been shown in T2D patients in comparison with healthy subjects [8]. A hypercoagulable state, detected by thrombin generation tests, was reported in patients with T2D, explaining, at least partially, the high incidence of vascular events in these patients [9]. Platelets of patients with DM are characterized by dysregulation of several signaling pathways, leading to an hyperreactive phenotype with enhanced adhesion, aggregation, and activation [10]. Chronic hyperglycemia has been clearly identified as a causal factor for in vivo platelet activation [11]. Our group firstly demonstrated enhanced thromboxane (TX) biosynthesis in T2D, providing evidence for its platelet origin. Moreover, tight metabolic control led to reduction of TX metabolite urinary levels [11]. Interestingly, inflammatory mediators (such as CD40L) derived from platelets expand the functional repertoire of platelets from players of hemostasis and thrombosis to powerful amplifiers of inflammation by promoting the release of cytokines and chemokines, cell activation and cell–cell interactions [12]. T2D is frequently associated with a dyslipidemic state that may accelerate the progression of atherosclerotic F. Perego Internal Medicine III, Luigi Sacco Hospital, University of Milan, Milan, Italy

Recombinant C1-Inhibitor

Recombinant human C1-inhibitor (rhC1INH; Ruconest®) has been developed for treatment of acute angioedema attacks in patients with hereditary angioedema (HAE) due to heterozygous deficiency of C1INH. Previous reports suggest that administration of plasma-derived C1INH products may be associated with an increased risk for thromboembolic complications. Our aim is to evaluate the effects of rhC1INH on coagulation and fibrinolysis in symptomatic HAE patients. Levels of various coagulation and fibrinolytic parameters were determined in pre- and post-exposure plasma samples from HAE patients included in a randomized clinical trial. Patients were treated with either saline, or 50 or 100 U/kg rhC1INH for an acute angioedema attack. Prior to rhC1INH treatment, the majority of patients had low to normal activated partial thromboplastin times (aPTT) and increased levels of prothrombin fragment 1+2, thrombin-antithrombin complexes, D-dimers and plasmin-antiplasmin complexes, all of which indicate activation of both coagulation and fibrinolysis. Infusion of rhC1INH at doses up to 100 U/kg did not affect these parameters except for a dose-dependent prolongation of aPTT, confirming that rhC1INH is an inhibitor of the contact system, and that F1+2 levels decreased. Coagulation and fibrinolytic systems are activated in HAE patients suffering from an acute angioedema attack. Treatment with rhC1INH at 50 or 100 U/kg had no effect on parameters reflecting activation of these systems except for a significant effect on aPTT, which likely reflects a pharmacodynamic effect of rhC1INH, and a reduction on plasma levels of the prothrombin activation fragment F1+2. We conclude that these results argue against a prothrombotic effect of treatment with this rhC1INH product in HAE patients.