thromboplastin and Coronary-Artery-Disease

The contribution of vessel wall-derived tissue factor (TF) to atherothrombosis is well established, whereas the pathophysiological relevance of the blood-borne TF is still a matter of debate, and controversies on the presence of platelet-associated TF still exist. In the past 15 years, several studies have documented the presence of TF in human platelets, the capacity of human platelets to use TF mRNA to make de novo protein synthesis, and the increase in the percentage of TF positive platelets in pathological conditions such as coronary artery disease (CAD). The exposure of vessel wall-derived TF at the site of vascular injury would play its main role in the initiation phase, whereas the blood-borne TF carried by platelets would be involved in the propagation phase of thrombus formation. More recent data indicate that megakaryocytes are committed to release into the bloodstream a well-defined number of TF-carrying platelets, which represents only a fraction of the whole platelet population. These findings are in line with the evidence that platelets are heterogeneous in their functions and only a subset of them is involved in the hemostatic process. In this review we summarize the existing knowledge on platelet associated TF and speculate on its relevance to physiology and to atherothrombosis and CAD.

Topics: Animals; Atherosclerosis; Blood Platelets; Coronary Artery Disease; Humans; Megakaryocytes; Thromboplastin; Thrombosis

Hyperlipidemia leads to the formation of oxidized LDL (oxLDL), vessel dysfunction, atherosclerotic disease, and ultimately to plaque rupture and thrombosis. OxLDL induces tissue factor (TF) expression in various cell types, including monocytes and macrophages. High levels of TF are present in atherosclerotic plaques and this represents that major source of TF that triggers thrombosis after plaque rupture. In addition, increased levels of "circulating TF" are observed in hyperlipidemic animals and patients. This is due to induced TF expression in monocytes and release of monocyte-derived, TF(+) microparticles, which represents a minor source of TF that likely contributes to thrombosis after plaques rupture. This review will summarize the connections between hyperlipidemia and TF expression within atherosclerotic plaques and circulating monocytes, as well as its inhibition by statins.

Topics: Animals; Coronary Artery Disease; Humans; Lipoproteins, LDL; Plaque, Atherosclerotic; Rupture, Spontaneous; Thromboplastin; Thrombosis

The term "vulnerable plaque" identifies atherosclerotic lesions prone to rupture. Plaque disruption facilitates the interaction of the inner components of the lesion, tissue factor (TF) among them, with the flowing blood. This results in activation of the coagulation cascade, ultimately leading to thrombus formation, and abrupt vascular occlusion. Despite the central role of vulnerable plaques in the onset of acute coronary syndromes (ACS), there are certain conditions (e.g., eroded plaques) where a hyperactive, "vulnerable" blood, may play a predominant pathophysiological role. Recently, two distinct pools of circulating TF have been identified. One, associated with cell-derived microparticles probably originating from apoptotic cells, such as macrophages, smooth muscle cells, and endothelium. The most recent, blood-borne TF, circulates in an "inactive" form (encryption) and has to be activated (decryption) to exert its thrombogenic activity. Certain pathological conditions associated with an increased rate of thrombotic complications have been associated with high levels of circulating TF. It is thought that the blood-borne TF perpetuates the initial thrombogenic stimulus, leading to the formation of larger or more stable thrombus, and thus, more severe ACS. Thus, the concept of vulnerable blood could represent a new link between the vulnerable lesion and the high-risk patient. Therefore, the assessment of selected biomarkers associated with "vulnerable or hyperreactive blood", e.g., blood-borne tissue factor, may represent a useful tool to identify patients with a high-risk profile of developing major cardiovascular events.

Topics: Acute Coronary Syndrome; Atherosclerosis; Biomarkers; Cell-Derived Microparticles; Coronary Artery Disease; Humans; Thromboplastin

The aim of this overview is to summarize the available data on the involvement of monocytes in the pathological processes related to the development of acute coronary syndromes and the recovery of damaged areas, the prevention of excessive inflammatory and procoagulant response, and the restoration of microcirculation (angiogenesis).

Topics: Acute Coronary Syndrome; Animals; Blood Platelets; Cell Communication; Chemokine CCL2; Coronary Artery Disease; Endothelial Cells; Humans; Inflammation; Lipoproteins, LDL; Monocytes; Stem Cells; Thromboplastin

Tissue factor is a cell surface protein that is expressed constitutively by monocytes, macrophages and fibroblasts, but also by some other cells in response to a variety of stimuli. The main function of the tissue factor is to form a complex with factor VII/VIIa that converts factors IX and X to their active forms. Tissue factor is also involved in the pathophysiology of systemic inflammatory disorders, coagulopathies, atherosclerotic disease, tumor angiogenesis and metastasis. Increased tissue factor expression either locally in the coronary plaques or systematically on circulating blood elements of patients with acute coronary syndromes may be responsible for increased thrombin generation, thus leading to platelet activation and fibrin formation. Tissue factor therefore plays a pivotal role in the initiation of thrombotic complications in patients with coronary artery disease.

Topics: Biomarkers; Coronary Artery Disease; Coronary Thrombosis; Humans; Thromboplastin

Atherothrombotic vascular disease is a complex disorder in which inflammation and coagulation play a pivotal role. Rupture of high-risk, vulnerable plaques with the subsequent tissue factor (TF) exposure is responsible for coronary thrombosis, the main cause of unstable angina, acute myocardial infarction, and sudden cardiac death. Tissue factor (TF), the key initiator of coagulation is an important modulator of inflammation. TF is widely expressed in atherosclerotic plaques and found in macrophages, smooth muscle cells, extracellular matrix and acellular lipid-rich core. TF expression can be induced by various stimulants such as C-reactive protein, oxLDL, hyperglycemia and adipocytokines. The blood-born TF encrypted on the circulating microparticles derived from vascular cells is a marker of vascular injury and a source of procoagulant activity. Another form of TF, called alternatively spliced has been recently identified in human and murine. It is soluble, circulates in plasma and initiates coagulation and thrombus propagation. Evidence indicates that elevated levels of blood-borne or circulating TF has been associated with metabolic syndrome, type 2 diabetes and cardiovascular risk factors and is a candidate biomarker for future cardiovascular events. Therapeutic strategies have been developed to specifically interfere with TF activity in the treatment of cardiovascular disease.

Topics: Coronary Artery Disease; Coronary Thrombosis; Diabetes Mellitus; Endothelium, Vascular; Humans; Hyperglycemia; Inflammation; Obesity; Thromboplastin

The development of anticoagulants for treating patients with atherothrombotic disorders of the arterial circulatory system has focused, either directly or indirectly, on thrombin - a pleuripotential effector enzyme with prothrombotic and proinflammatory properties. The pivotal role of factor (f) Xa in thrombin generation, coupled with its direct cellular effects and widely recognized limitations of currently available anticoagulants, has led to the development of pharmacologic inhibitors of this important protease. The following review focuses on DX-9065a - first in a class of direct, selective and reversible fXa antagonists - and its potential applications in the management of patients with cardiovascular disease.

Topics: Animals; Anticoagulants; Area Under Curve; Blood Coagulation; Cardiovascular Diseases; Clinical Trials as Topic; Coronary Artery Disease; Disease Models, Animal; Dose-Response Relationship, Drug; Factor Xa; Factor Xa Inhibitors; Humans; International Normalized Ratio; Mice; Models, Biological; Models, Chemical; Naphthalenes; Pilot Projects; Platelet Aggregation Inhibitors; Propionates; Rats; Thrombin; Thromboplastin; Thrombosis; Time Factors

Recent advances in basic science have linked some systemic risk factors to endothelial dysfunction which gives rise to atherosclerotic disease and triggers the progression of thrombotic complications. Superficial erosion of the stenotic plaque can be observed in one-third of acute coronary syndromes (ACS). In these cases the presence of classic risk factors such as diabetes mellitus, hypercholesterolemia and smoking favor a state of "vulnerable blood" or high risk. Increased thrombogenicity can exacerbate thrombus formation and is able to trigger an ACS. The vessel endothelium regulates contractile, mitogenic and thrombotic activities of the vessel wall. Risk factors impair both homeostasis and hemostasis of the vessel wall and promote inflammatory signals. Platelet and monocyte activation favors the expression of tissue factor (TF), thus triggering the coagulation cascade with thrombin generation and clot formation. Increased blood thrombogenicity linked to classic risk factors may be associated with circulating TF levels which are much higher than those observed in healthy subjects without risk factors. These observations not only emphasize the usefulness of aggressive management of risk factors but open a new avenue for future studies to devise therapeutic strategies to treat ACS by inhibiting TF expression.

Topics: Acute Disease; Coronary Artery Disease; Coronary Thrombosis; Diabetes Complications; Humans; Hypercholesterolemia; Risk Factors; Smoking; Syndrome; Thromboplastin

Thrombosis at the site of atherosclerotic plaque disruption is the principal cause of acute coronary syndromes. The severity of the clinical consequences is determined by the extent and the progression of the thrombus that are caused by local and systemic factors. In atherosclerotic lesions mediators induce tissue factor (TF) in macrophages, smooth muscle cells, and endothelial cells. Procoagulant microparticles in the lipid core further enhance the thrombogenicity of the plaque. In addition, in acute coronary syndromes circulating monocytes and microparticles express TF and, thereby, contribute to systemic procoagulant activity. As a regulatory mechanism surface-bound, endogenous tissue factor pathway inhibitor-1 (TFPI) inhibits TF activity by translocation of the quaternary complex TF-FVIIa-FXa-TFPI into glycosphingolipid-rich microdomains more efficiently than exogenously added TFPI. This inhibition occurs not only in endothelial cells but also on circulating monocytes and presumably microparticles. Because therapeutic thrombolysis in acute myocardial infarction degrades TFPI, a prothrombotic state due to unopposed TF activity may occur. Several studies have demonstrated a contribution of local and bloodborne TF to thrombus formation; a direct relationship with the clinical outcome, however, awaits further studies. This article discusses the current understanding of the role of TF and its regulation by TFPI in acute coronary syndromes.

Topics: Angina, Unstable; Antithrombin III; Coronary Artery Disease; Coronary Thrombosis; Humans; Lipoproteins; Myocardial Infarction; Thromboplastin

Plaque disruption with superimposed thrombosis is the main cause of acute coronary events such as acute myocardial infarction and unstable angina. Among other factors, tissue factor seems to play an important role determining plaque thrombogenicity. Tissue factor is a potent initiator of the coagulation cascade situated within the vessel wall and is highly exposed to the blood after plaque rupture. Several mediators involved in the process of atherosclerotic plaque formation are capable of inducing tissue factor expression in cells such as monocytes, macrophages and endothelial cells, which under normal conditions do not express tissue factor or to a limited extent only. The increased expression of tissue factor is not limited to the plaque but is also found in circulating monocytes in patients with acute coronary syndromes. In addition, studies have shown an important contribution of tissue factor in the pathogenesis of thrombosis and restenosis after balloon angioplasty. Recent basic studies focus on the therapeutic inhibition of tissue factor. Specific and non-specific inhibitors of tissue factor or the tissue factor/factor VIIa complex have been developed or identified, and have been tested in experimental studies. Clinical studies are currently being initiated. In this review, we present the current knowledge on the role of tissue factor in atherosclerosis, arterial intervention and potential pharmacological approaches, with focus on acute coronary syndromes.

Topics: Acute Disease; Angioplasty, Balloon, Coronary; Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antibodies, Monoclonal; Anticoagulants; Arginine; Aspirin; Coronary Artery Disease; Coronary Thrombosis; Cyclosporine; Endothelium, Vascular; Factor VIIa; Heparin, Low-Molecular-Weight; Hirudin Therapy; Humans; Hypolipidemic Agents; Leukocytes, Mononuclear; Muscle, Smooth, Vascular; Recombinant Proteins; Thrombin; Thromboplastin

An occlusive thrombus in the coronary arteries is the critical pathological event that immediately precedes most cases of myocardial infarction. Often the thrombus originates with a bleed from a fissured atheroma. Atheroma formation, therefore, creates risk of thrombosis; asymptomatic episodes of thrombosis and healing contribute to the pathogenesis of atherosclerosis and the development of atherosclerotic plaques. Based largely on in vitro and animal model evidence, infectious agents and their products can activate the coagulation cascade enzymatically or by up-regulating tissue factor. By initiating a procoagulant response, infectious agents can indirectly trigger a prothrombotic response. Alternatively, some microbes can directly trigger platelet aggregation in vitro and in animal models, suggesting direct prothrombotic potential in human cardiovascular disease. Activation of coagulation and thrombosis characterizes the pathological response to infectious agents in human disseminated intravascular coagulation and infective endocarditis. Given the underlying biological plausibility, the cumulative lifetime burden of chronic pathogens may be expected to create risk of atherosclerosis and thrombosis, and, indirectly, signs of cardiovascular disease.

Topics: Animals; Antigens, Bacterial; Bacteremia; Bacterial Proteins; Blood Coagulation; Cardiovascular Diseases; Collagen; Coronary Artery Disease; Coronary Thrombosis; Disease Models, Animal; Disseminated Intravascular Coagulation; Endocarditis, Bacterial; Humans; Platelet Aggregation; Risk Factors; Thromboplastin; Thrombosis

The rupture or fissuring of a coronary atherosclerotic plaque and subsequent thrombosis is considered the key event in the pathogenesis of unstable angina and myocardial infarction. Although plaque disruption frequently occurs during the evolution of atherosclerosis, only a minority of ruptured plaques develop thrombosis. The content and procoagulant activity of tissue factor in human coronary atherosclerotic plaques varies widely, and different studies confirm that it is higher in the plaques extracted from patients with unstable angina, myocardial infarction or histologic/angiographic evidence of coronary thrombosis than in those taken from patients with stable angina or uncomplicated coronary lesions. Variations in tissue factor content and activity may be responsible for the different thrombotic responses to human coronary atherosclerotic plaque rupture.

Topics: Coronary Artery Disease; Humans; Thromboplastin

Topics: Arteriosclerosis; Coronary Artery Disease; Coronary Vessels; Humans; Muscle, Smooth, Vascular; Thromboplastin; Thrombosis

Thrombosis is a key feature of the initiation and progression of atherosclerosis and its clinical sequelae. Acute thrombosis can lead to arterial occlusion and consequently provoke myocardial infarction, unstable angina, stroke and sudden death. Acute thrombosis can also be a complication of arterial bypass surgery, balloon angioplasty, atherectomy, or coronary artery stenting. The thrombotic response is influenced by several factors, among them the thrombogenicity of the vessel wall and of certain blood components as well as their interaction with the lipid pool. Tissue factor (TF) is considered to be the primary cofactor of cellular origin that is involved in activation of the coagulation pathway. The active form of TF has been shown to be present in specimens of human coronary artery in association both with acellular lipid areas and with macrophages and smooth muscle cells, which suggests that TF plays a major role in determining plaque thrombogenicity. We discuss here what is currently known about the role of tissue factor in atherogenesis, and focus attention on pharmacological approaches in this area.

Topics: Arteriosclerosis; Coronary Artery Disease; Coronary Thrombosis; Coronary Vessels; Humans; Thromboplastin; Thrombosis

Atherosclerosis is vascular disease characterized by thickening, hardening, and remodelling of the arterial wall. Occlusive vascular disease most often results from thrombosis superimposed on atherosclerotic plaque. Lipoproteins enter the vessel wall, promoting the recruitment of monocytes, which imbibe lipids and become foam cells. Smooth muscle cells invade these early plaques, producing connective tissue fibrils that form a fibrous cap over the lipid center; rupture of this cap is an important cause of thrombosis. The specific topography of early atherosclerotic lesions is primarily attributed to wall shear stress, one of hemodynamic forces. Inflammatory mediators regulate processes that determine the composition of the plaque's fibrous cap, a structure that separates blood from the thrombogenic lipid core. Factors involved in coagulation, such as thrombin, can regulate non-thrombotic functions of vascular wall cells such as smooth muscle proliferation or cytokine release. Tissue factor is a major regulator of coagulation and hemostasis. When the plaques are ruptured or eroded, exposure of cellular and extracellular tissue factor to circulating blood play a pivotal role in mediating fibrin-rich thrombus formation leading to acute coronary syndromes. Several serial angiographic studies have demonstrated that over 70% of acute coronary syndromes evolve from mildly to moderately obstructive atherosclerotic plaques.

Topics: Arteriosclerosis; Coronary Artery Disease; Humans; Thromboplastin; Thrombosis

Observational studies reveal a cardioprotective effect of hormone replacement therapy. The precise mechanisms whereby this treatment influences disease risk are not fully understood. Much attention has been paid to changes in lipid and lipoprotein metabolism, but this explains only part of the protective effect. In this short review, the roles of monocyte and platelet function in atherogenesis and thrombus formation are discussed. It is shown that hormone replacement therapy favourably down-regulates monocyte and platelet reactivity, which may be important in explaining the beneficial effect on the risk of cardiovascular disease.

Topics: Adult; Aged; Blood Platelets; Coronary Artery Disease; Coronary Disease; Coronary Thrombosis; Estrogen Replacement Therapy; Female; Humans; Middle Aged; Monocytes; Thromboplastin; Thromboxanes; Tumor Necrosis Factor-alpha

The disruption of an atherosclerotic plaque in a coronary artery, appears to be fundamental for the development of arterial thrombosis and resultant ischaemia. Platelets play a central role in the pathogenesis of unstable angina; they can aggregate and cause mechanical obstruction if large enough. In addition, they can lead to fibrin deposition and extension of the thrombus. The fundamental goal in the treatment of unstable angina is to control the acute disease process that leads to vascular occlusion. In addition to the currently available pharmacological agents used to treat unstable angina, newer agents such as the direct thrombin inhibitors and the glycoprotein IIb/IIIa receptor antagonists may be more effective in achieving 'passivation'. This article summarizes the role of the vessel wall and its interaction with platelets in arterial thrombosis. The different pharmacological approaches used in achieving passivation of platelets in unstable angina are described.

Topics: Acute Disease; Angina, Unstable; Angioplasty, Balloon, Coronary; Animals; Anticoagulants; Antithrombins; Blood Platelets; Coronary Artery Disease; Coronary Thrombosis; Drug Delivery Systems; Drug Therapy, Combination; Endothelium, Vascular; Humans; Infusions, Intra-Arterial; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Rabbits; Thromboplastin

A major concern of stent implantation after percutaneous coronary intervention (PCI) is acute stent thrombosis. Effective inhibition of periprocedural platelet function in patients with coronary artery disease (CAD) leads to an improved outcome. In this study, we examined the periprocedural platelet reactivity after administrating bivalirudin during PCI compared to unfractionated heparin (UFH) administration. Further, the effect of bivalirudin on induced tissue factor (TF) expression in smooth muscle cells (SMC) was determined.. Patients with CAD (n = 58) and double antithrombotic medication were treated intraprocedural with UFH (n = 30) or bivalirudin (n = 28). Platelet activation markers were flow cytometrically measured before and after stenting. The expression of TF in SMC was determined by real-time PCR and Western blotting. The thrombogenicity of platelet-derived microparticles and SMC was assessed via a TF activity assay.. Bivalirudin significantly diminished the agonist-induced platelet reactivity post-PCI. Compared to UFH treatment, the adenosine diphosphate (ADP) and thrombin receptor-activating peptide (TRAP)-induced thrombospondin expression post-PCI was reduced when bivalirudin was administrated during intervention. In contrast to UFH, bivalirudin reduced the P-selectin expression of unstimulated and ADP-induced platelets post-PCI. Moreover, bivalirudin inhibited the thrombin-, but not FVIIa- or FVIIa/FX-induced TF expression and pro-coagulant TF activity of SMC. Moreover, bivalirudin reduced the TF activity of platelet-derived microparticles postinduction with TRAP or ADP.. Bivalirudin is better than UFH in reducing periprocedural platelet activation. Moreover, thrombin-induced TF expression is inhibited by bivalirudin. Thus, bivalirudin seems to be a better anticoagulant during PCI than UFH.

Topics: Aged; Anticoagulants; Antithrombins; Biomarkers; Blood Platelets; Blotting, Western; Cells, Cultured; Coronary Artery Disease; Factor VIIa; Factor X; Female; Flow Cytometry; Germany; Heparin; Hirudins; Humans; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; P-Selectin; Peptide Fragments; Percutaneous Coronary Intervention; Platelet Activation; Platelet Function Tests; Real-Time Polymerase Chain Reaction; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stents; Tetraspanin 30; Thromboplastin; Thrombospondins; Treatment Outcome

In patients with stable coronary heart disease (n = 1,001) we investigated the influence of tissue factor (TF) and TF pathway inhibitor (TFPI) polymorphisms on thrombin generation in vivo, measured by prothrombin fragment (F) 1 and 2, and the potential to generate thrombin ex vivo, measured by the calibrated automated thrombogram assay. Additionally, circulating levels of TF and TFPI were correlated to the different parameters of thrombin generation. The TF 5466 and TFPI -399 polymorphisms associated with higher thrombin generation in vivo, the latter also with a prolonged lag time of the thrombin generation ex vivo(p < 0.05 for all).The TF -1812 TT and the TF -603 GG genotypes were associated with lower peak thrombin and a decreased average net rate of thrombin activation during the propagation phases (p ≤ 0.05), and the TFPI -33 TC genotype with prolonged lag time (p < 0.05) and additionally time to peak (p = 0.06). Strong correlations between TFPI levels, prothrombin fragment 1 and 2 as well as calibrated automated thrombogram parameters were observed.

Topics: Adult; Aged; Aged, 80 and over; Coronary Artery Disease; Female; Genotype; Humans; Lipoproteins; Male; Middle Aged; Polymorphism, Genetic; Thromboplastin

Heparinization requires monitoring, but optimal methods for measuring the anticoagulant effects of heparin remain to be determined. We compared prothrombinase-induced clotting time (PiCT) and two chromogenic anti-factor Xa activity (anti-Xa) assays in monitoring high-dose heparinization during cardiopulmonary by-pass (CPB). Heparin effects were serially measured with PiCT and two anti-Xa assays in 100 patients. Antithrombin and protein C activities were measured preoperatively, and antithrombin activity was measured during CPB. Activation of coagulation was assessed with measurements of prothrombin fragment F1+2, soluble fibrin complexes, and D-dimer before, during, and after CPB. During CPB mean ranges of PiCT and of anti-Xa heparin levels measured with (anti-Xa A) and without (anti-Xa B) dextran sulfate and antithrombin supplementation were 5.0-5.2, 4.7-5.0, and 4.5-4.9 IU/ml, respectively. There was poor agreement between PiCT and anti-Xa and between the two anti-Xa assays (r = 0.32-0.65 and broad limits of agreement). Patients with low preoperative antithrombin or protein C levels had lower PiCT (p = 0.028 and p = 0.01) and anti-Xa A (both p<0.001) levels during CPB than others. Patients with the lowest heparin activities during CPB (lowest deciles of PiCT and anti-Xa A) had higher subsequent F1+2 after CPB (p = 0.002 and p = 0.02), and patients with high heparin levels required fewer transfusions of packed red blood cells than others. In conclusion, in the challenging setting of CPB there is poor agreement between anti-Xa assays and PiCT. However, coagulation-based PiCT could provide an alternative to the chromogenic anti-Xa assays. Higher heparin levels during CPB were confirmed to associate with reduced transfusion requirements.

Topics: Adult; Aged; Aged, 80 and over; Anticoagulants; Antithrombins; Blood Coagulation; Blood Coagulation Tests; Blood Loss, Surgical; Cardiopulmonary Bypass; Chromogenic Compounds; Coronary Artery Bypass; Coronary Artery Disease; Drug Monitoring; Erythrocyte Transfusion; Factor Xa; Factor Xa Inhibitors; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Heparin; Humans; Male; Middle Aged; Monitoring, Intraoperative; Peptide Fragments; Prospective Studies; Protein C; Prothrombin; Thromboplastin

Exposure of tissue factor (TF) is a critical proximal step in the pathogenesis of acute coronary syndromes. Sunol-cH36, a chimaeric monoclonal antibody to TF, blocks binding of factor X to the TF:VIIa complex. This report describes the first completed trial of Sunol-cH36 in humans.. We assessed the safety and pharmacokinetics of Sunol-cH36 in an open-label, dose-escalating trial among subjects with stable coronary artery disease. The safety analysis included all adverse events with a focus on overt or occult bleeding. Five doses of Sunol-cH36 (0.03, 0.06, 0.08, 0.1, 0.3 mg/kg) were administered as a single intravenous bolus to 26 subjects (three to eight subjects per dose tier). No major bleeding (> or =2 g/dL haemoglobin decline) occurred. Spontaneous minor bleeding was observed with a dose-related pattern. Notably, the majority of spontaneous bleeding episodes were clinically consistent with platelet-mediated bleeding (e.g. gum, tongue) without thrombocytopenia. The median terminal half-life was 72.2 (25th, 75th: 28.4, 72.5) h.. Sunol-cH36 exhibited dose-dependent anticoagulant effects. We postulate that the mucosal bleeding observed with this potent inhibitor of thrombin generation may reflect antiplatelet effects resulting from networking between the coagulation cascade and platelet pathways that could prove clinically relevant with this novel class of anticoagulants.

Topics: Adult; Aged; Antibodies, Monoclonal; Aspirin; Blood Coagulation; Cohort Studies; Coronary Artery Disease; Dose-Response Relationship, Drug; Female; Half-Life; Hemorrhage; Humans; Injections, Intravenous; Male; Middle Aged; Platelet Aggregation Inhibitors; Thrombin; Thromboplastin

Interleukin-6 (IL-6) and macrophage colony stimulating factor plasma levels are elevated in acute coronary syndromes. IL-6 has an inherent negative inotropic action and, with tissue factor (TF), mediates the ischemia-reperfusion myocardial injury. We hypothesized that inducible ischemia leads to cytokine production, TF expression, and consequently persistent left ventricular dysfunction after dobutamine stress echocardiography (DSE) in coronary artery disease patients.. DSE was performed in 103 patients with angiographically documented coronary artery disease. Blood samples were obtained at rest, at peak stress, and 30 minutes after cessation of dobutamine infusion for measurement of macrophage colony stimulating factor, IL-6, and TF. New or worsening wall motion abnormalities at peak stress and their duration into recovery were noted. Median IL-6 and TF levels were increased at peak stress and at 30 minutes into recovery compared with rest (2.7 and 2.4 versus 2.1 pg/mL for IL-6, 310 and 385 versus 266 pg/mL for TF [P<0.01] in patients with an ischemic response; n=55). Compared with rest, a greater release of IL-6 at peak stress and recovery was observed in patients with increasing number of ischemic segments at peak DSE (2 versus 3 to 4 versus 5 to 6 versus 7 to 8 segments; P=0.03). The time to recovery of wall motion abnormalities was also associated with IL-6 levels at peak stress and recovery (r=0.51 and r=0.39, P<0.05). Macrophage colony stimulating factor levels remained unchanged throughout DSE.. Reversible ischemia induced during DSE increases IL-6 and TF plasma levels. IL-6 is related to the extent of left ventricular dysfunction at peak stress and to persistent LV dysfunction during recovery.

Topics: Adult; Aged; Biomarkers; Coronary Artery Disease; Echocardiography, Stress; Female; Humans; Interleukin-6; Male; Middle Aged; Myocardial Ischemia; Predictive Value of Tests; Stroke Volume; Thromboplastin; Ventricular Dysfunction, Left

Tissue factor (TF; an initiator of coagulation) and vascular endothelial growth factor (VEGF; a marker of angiogenesis) are involved in the hypercoagulable state associated with malignancy. We investigated their roles in chronic atrial fibrillation (AF), a condition also associated with increased risk of stroke and thromboembolism, as well as a prothrombotic or hypercoagulable state.. We studied 25 patients with AF (20 men; mean+/-SD age, 62+/-13 years) who were compared with 2 control groups in sinus rhythm: 30 healthy control subjects (17 men; mean age, 60+/-9 years) and 35 patient control subjects with coronary artery disease (CAD; 27 men; mean age, 60+/-12 years). Plasma levels of TF, VEGF, and the VEGF receptor sFlt-1 were measured by enzyme-linked immunosorbent assay.. VEGF, sFlt-1, and TF were significantly different between the 3 groups, with abnormal levels in AF and CAD patients compared with control subjects (P<0.001, P=0.022, and P=0.008, respectively). Among the AF patients, TF levels were significantly correlated with VEGF (Spearman's r=0.65, P<0.001) and sFlt (r=0.54, P=0.006) levels. Only TF and VEGF levels were significantly correlated in CAD patients (r=0.39, P=0.02). There were no significant correlations among the healthy control subjects.. Patients with chronic AF have high TF levels, in keeping with the prothrombotic state associated with this arrhythmia. The relationships between TF and VEGF and its receptor sFlt-1 in AF suggest a possible role for VEGF in the hypercoagulable state found in AF, as seen in malignancy and atherosclerosis.

Topics: Anticoagulants; Atrial Fibrillation; Blood Pressure; Case-Control Studies; Chronic Disease; Coronary Artery Disease; Cross-Sectional Studies; Demography; Endothelial Growth Factors; Female; Humans; Lymphokines; Male; Middle Aged; Proto-Oncogene Proteins; Receptor Protein-Tyrosine Kinases; Thrombophilia; Thromboplastin; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1; Vascular Endothelial Growth Factors; Warfarin

Cardiac allograft vasculopathy (CAV) limits the long-term success of cardiac transplantation. The incidence of CAV is increased in patients with elevated plasma levels of oxidized lipids or fibrin deposition within right heart biopsy (RHB) specimens. The present study investigated whether tissue factor (TF), the expression of which is regulated by oxidized lipids, is upregulated in patients with CAV.. A TF score was developed to quantify TF expression in RHB specimens from 63 consecutive patients undergoing routine annual posttransplantation RHB and coronary angiography. In patients >2 years (3.0+/-0.8 years) posttransplantation (n=35), a high TF score was observed with greater frequency (75% versus 26%, P<0.004) in patients with CAV than those without CAV. In patients <2 years (0.87+/-0.48 years) posttransplantation (n=28) without evidence of CAV, the TF score was determined and patients were followed up prospectively. A high TF score had a positive predictive value of 78.6% for the development of CAV, and a low TF score had a negative predictive value of 100%.. These data demonstrate that early TF expression predicts subsequent development of CAV. Increased TF expression could link the elevated levels of oxidized LDL and fibrin deposition known to precede CAV. These findings suggest that TF may play a role in the pathophysiology of CAV and could offer a potential prognostic tool and a novel target for the prevention of CAV, possibly with antioxidants or inhibitors of the TF pathway.

Topics: Adult; Biomarkers; Coronary Angiography; Coronary Artery Disease; Follow-Up Studies; Heart Transplantation; Humans; Prognosis; Thromboplastin

Studies in healthy subjects showed that blood coagulation factor VII (FVII) is activated postprandially after consumption of high-fat meals, but accompanying thrombin formation has not been demonstrated. In patients with coronary atherosclerosis, the arterial intima is supposed to present more tissue factor, the cofactor of FVII, to circulating blood; therefore, thrombin formation in response to FVII activation is more likely to occur in such patients. This hypothesis was tested in a randomized crossover study of 30 patients (aged 43 to 70 years) with stable angina pectoris and angiographically verified coronary atherosclerosis. They were served a low-fat (5% of energy from fat) breakfast and lunch and a high-fat (40% of energy from fat) breakfast and lunch on 2 different days. Venous blood samples were collected at 8:15 AM (fasting), 12:30 PM, 2:00 PM, 3:30 PM, and 4:45 PM and analyzed for triglycerides, activated FVII (FVIIa), FVII protein concentration (FVII:Ag), prothrombin fragment 1+2 (F1+2), and soluble fibrin. Triglyceride levels increased from fasting levels on both diets, but they increased most markedly on the high-fat diet. FVIIa and FVIIa/FVII:Ag increased with the high-fat diet and decreased with the low-fat diet. For both diets, FVII:Ag and F1+2 decreased slightly. No postprandial changes were observed for soluble fibrin. Postprandial mean values of triglycerides, FVIIa, FVII:Ag, and FVIIa/FVII:Ag were significantly higher for the high-fat diet than for the low-fat diet. Our findings confirm that high-fat meals cause immediate activation of FVII. The clinical implication is debatable because FVII activation was not accompanied by an increase in plasma F1+2 concentrations in patients with severe atherosclerosis. However, a local thrombin generation on the plaque surface cannot be excluded.

Topics: Adult; Aged; Angina Pectoris; Coronary Artery Disease; Cross-Over Studies; Dietary Fats; Factor VII; Female; Humans; Male; Middle Aged; Peptide Fragments; Postprandial Period; Prothrombin; Thrombin; Thromboplastin

Tissue factor (TF) and activated factor XI (FXIa) have been associated with acute coronary syndrome, ischemic stroke and venous thromboembolism. Their predictive value in stable coronary artery disease (CAD) is unclear. We investigated whether active TF and FXIa were associated with clinical outcomes in CAD patients in long-term observation.. In 124 stable patients with multivessel CAD, we assessed the presence of circulating, active TF and FXIa by measuring a response of thrombin generation to respective inhibitory antibodies. We recorded the composite endpoint of myocardial infarction (MI), stroke, systemic thromboembolism and cardiovascular death during follow-up (median 106 months, interquartile range 95-119).. Circulating FXIa and active TF were detected in 40% and 20.8% of the 120 patients (aged 65.0 [57.0-70.3] years, men, 78.3%), who completed follow-up. The composite endpoint occurred more frequently in patients with detectable active TF and FXIa present at baseline (hazard ratio [HR] 4.02, 95% confidence interval [CI] 2.26-7.17, p < 0.001 and HR 6.21, 95% CI 3.40-11.40, p < 0.001, respectively). On multivariate analysis FXIa, but not active TF, was an independent predictor of the composite endpoint, as well as MI, stroke/systemic thromboembolism, and cardiovascular death, when analyzed separately.. To our knowledge, this study is the first to show that circulating FXIa predicts arterial thromboembolic events in advanced CAD, supporting a growing interest in FXIa inhibitors as novel antithrombotic agents.

Topics: Aged; Blood Coagulation Tests; Coronary Artery Disease; Factor IX; Factor XIa; Female; Humans; Male; Middle Aged; Myocardial Infarction; Risk Factors; Stroke; Thromboembolism; Thromboplastin

Coronary artery disease (CAD) is associated with a prothrombotic tendency including increased factor (F) VIIa-antithrombin (FVIIa-AT) complexes, a measure of tissue factor (TF) exposure, and activated FXI (FXIa). We investigated whether increased FVIIa-AT complexes are associated with FXIa and active TF and if major adverse clinical outcomes are predicted by the complexes in CAD.. In 120 CAD patients, we assessed FVIIa-AT complex concentrations and the presence of circulating FXIa and active TF. Levels of 8-iso-prostaglandin F2α (8-iso-PGF2α), interleukin-6, high-sensitivity C reactive protein, prothrombin fragment 1 + 2, and free Tissue Factor Pathway Inhibitor were determined. Myocardial infarction (MI), ischemic stroke, systemic thromboembolism (SE), and cardiovascular (CV) death were recorded separately and as a composite endpoint, during follow-up.. FVIIa-AT complexes were positively associated with current smoking and multivessel CAD. Elevated FVIIa-AT complexes characterized patients with circulating FXIa and/or active TF in association with increased plasma isoprostanes but not with thrombin generation or inflammatory markers. During a median follow-up of 106 months (interquartile range 95-119), high baseline levels of FVIIa-AT complexes predicted ischemic stroke/SE (HR 4.61 [95% CI 1.48-18.42]) and a composite endpoint of MI, stroke/SE, and CV death (HR 7.47 [95% CI 2.81-19.87]).. This study is the first to show that high FVIIa-AT complexes characterize advanced CAD patients with detectable FXIa and active TF, which is, in part, driven by oxidative stress. High FVIIa-AT complexes were associated with the risk of ischemic stroke/SE during long-term follow-up, highlighting the need for effective antithrombotic agents in CAD.

Topics: Anticoagulants; Antithrombin III; Antithrombins; Coronary Artery Disease; Factor VIIa; Factor XIa; Humans; Ischemic Stroke; Myocardial Infarction; Thromboplastin

High plasma levels of activated Factor VII-Antithrombin complex (FVIIa-AT) have been associated with an increased risk of cardiovascular mortality in patients with stable coronary artery disease (CAD).. To investigate if FVIIa-AT levels are associated with activated factor X generation (FXaG) in modified assays.. Forty CAD patients were characterized for FVIIa-AT levels by ELISA and for FXaG in plasma. Novel fluorogenic FXaG assays, based on aptamers inhibiting thrombin and/or tissue factor pathway inhibitor (TFPI), were set up.. High FVIIa-AT plasma levels were associated with increased FXaG. Hypercoagulability features were specifically detectable in the coagulation initiation phase, which may have implications for cardiovascular risk prediction by either FVIIa-AT complex measurement or modified FXaG assays.

Topics: Coronary Artery Disease; Factor VIIa; Factor Xa; Humans; Thrombin; Thrombophilia; Thromboplastin

The prevalence of a macrophage phenotype in atherosclerotic plaque may drive its progression and/or instability. Macrophages from coronary plaques are not available, and monocyte-derived macrophages (MDMs) are usually considered as a surrogate. We compared the MDM profile obtained from coronary artery disease (CAD) patients and healthy subjects, and we evaluated the association between CAD MDM profile and in vivo coronary plaque characteristics assessed by optical coherence tomography (OCT). At morphological analysis, MDMs of CAD patients had a higher prevalence of round than spindle cells, whereas in healthy subjects the prevalence of the two morphotypes was similar. Compared to healthy subjects, MDMs of CAD patients had reduced efferocytosis, lower transglutaminase-2, CD206 and CD163 receptor levels, and higher tissue factor (TF) levels. At OCT, patients with a higher prevalence of round MDMs showed more frequently a lipid-rich plaque, a thin-cap fibroatheroma, a greater intra-plaque macrophage accumulation, and a ruptured plaque. The MDM efferocytosis correlated with minimal lumen area, and TF levels in MDMs correlated with the presence of ruptured plaque. MDMs obtained from CAD patients are characterized by a morpho-phenotypic heterogeneity with a prevalence of round cells, showing pro-inflammatory and pro-thrombotic properties. The MDM profile allows identifying CAD patients at high risk.

Topics: Aged; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Atherosclerosis; Cell Shape; Cells, Cultured; Coronary Artery Disease; Female; GTP-Binding Proteins; Humans; Lectins, C-Type; Macrophages; Male; Mannose Receptor; Mannose-Binding Lectins; Middle Aged; Plaque, Atherosclerotic; Protein Glutamine gamma Glutamyltransferase 2; Receptors, Cell Surface; Thromboplastin; Tomography, Optical Coherence; Transglutaminases

To understand the coagulation changes after off-pump coronary artery bypass (OPCAB) surgery, we evaluated the procoagulant activity of microparticles (MPs) and microparticles exposing tissue factor (MPs-TF), together with the levels of total tissue factor (TF), protein Z (PZ), protein Z-dependent protease inhibitor (ZPI), and factor X (FX) before (first day) and 1 week after surgery (seventh day) in plasma samples from 30 patients. Twenty healthy controls were also included. Compared to the controls, patients scheduled for surgery had significantly higher MPs-TF procoagulant activity and lower TF levels ( P = .0006, P = .02, respectively). In the whole cohort, median procoagulant activity of MPs-TF and median levels of TF and ZPI were significantly lower ( P = .02, P = .0003, and P = .004, respectively), while median levels of PZ and FX were significantly higher ( P = .02 and P = .002, respectively) on the seventh day compared to the first day. Our results suggest that OPCAB surgery has a significant effect on the procoagulant activity of MPs-TF and the PZ system.

Topics: Aged; Biomarkers; Blood Proteins; Case-Control Studies; Cell-Derived Microparticles; Coronary Artery Bypass, Off-Pump; Coronary Artery Disease; Humans; Male; Middle Aged; Pilot Projects; Thromboplastin

Microparticles (MPs) are formed from platelets (PMPs), endothelial cells (EMPs) and monocytes (MMPs), and in acute myocardial infarction (MI), there is an increase of MPs in the culprit artery. In this study MPs were evaluated in whole blood in 105 patients with MI at five time-points during a two-year follow-up (FU). Patients with non-ST-elevated MI had higher concentrations of CD41+MPs compared to ST-elevated MI patients (p=0.024). The concentrations of PMPs in whole blood increased during the time period (p<0.001), but no significant change over time was found for EMPs and MMPs. CD62P+MP counts were higher in MI patients with diabetes (p=0.020), and patients with hypertension had increased levels of CD14+MPs (p=0.004). The amount of CD62P+TF+MPs increased significantly during FU (p<0.001). Patients with atherosclerosis in three arterial beds, i. e. coronary, carotid and peripheral arteries, had lower concentrations of CD62P+TF+MPs (p=0.035) and CD144+TF+MPs (p=0.004) compared to patients with atherosclerosis in one or two arterial beds. Higher concentrations of CD62P+MPs early after MI were associated with an increased risk of cardiovascular events during FU, hazard ratio 3.32 (95 %CI1.20-9.31). Only small variations in PMP, EMP and MMP concentrations were found during long-term FU after MI and their levels seem to reflect the underlying cardiovascular disease rather than the acute MI. PMPs expressing P-selectin might be a promising biomarker for predicting future cardiovascular events, but further studies are needed to confirm these results.

Topics: Aged; Annexin A5; Antigens, CD; Biomarkers; Blood Platelets; Cadherins; Carotid Artery Diseases; Cell-Derived Microparticles; Comorbidity; Coronary Artery Disease; Endothelial Cells; Female; Follow-Up Studies; Humans; Lipopolysaccharide Receptors; Male; Middle Aged; Monocytes; Myocardial Infarction; P-Selectin; Peripheral Arterial Disease; Prognosis; Risk Assessment; Risk Factors; Sweden; Thromboplastin; Time Factors

The knowledge of circadian variation of microparticles (MPs) in stable coronary artery disease (SCAD) is limited. The aim of this study was to evaluate the daily variation of platelet-, endothelial- and monocyte-derived MPs in whole blood and their tissue factor expression (TF) in SCAD and whether these MPs were related to other endothelial and coagulation markers.. Serial blood samples from patients with SCAD were collected during one day. Flow cytometry was used to evaluate the amount of large MPs 0.5-1.0 μm, positive for annexin, and their expression of CD41, CD62P, CD144, CD14 and TF. The lag time and endogenous thrombin potential (ETP) was calculated by Calibrated Automated Thrombogram and soluble (s)P-selectin, sTF and vWF by ELISA.. The majority of MPs in whole blood consisted of CD41 + MPs with no significant daily variation. In contrast, the concentration of CD62P + MPs described a daily variation with the lowest concentrations found in the evening (p = 0.031). CD62P + and CD144 + MPs had the highest expression of TF, 52.6% and 42.9%, respectively, and correlated to the endothelial activity evaluated by vWF. There was a circadian rhythm of lag time (p < 0.001) and ETP (p = 0.001). The CD62P+, CD14 + and CD144 + MPs correlated to the lag time.. The different subsets of platelet-, endothelial- and monocyte-derived MPs do not present the same circadian variation and they differ in TF expression in SCAD. The MPs from activated platelets, endothelial cells and monocytes exist in low concentrations in whole blood but are related to the endothelial and coagulation activity found in SCAD.

Topics: Aged; Angina, Stable; Antigens, CD; Blood Platelets; Cadherins; Case-Control Studies; Cell-Derived Microparticles; Circadian Rhythm; Coronary Artery Disease; Female; Humans; Male; Middle Aged; Monocytes; P-Selectin; Platelet Membrane Glycoprotein IIb; Thrombin; Thromboplastin

Plasma concentration of activated factor VII (FVIIa)-antithrombin (AT) complex has been proposed as an indicator of intravascular exposure of tissue factor.. The aims of this observational study were to evaluate (i) FVIIa-AT plasma concentration in subjects with or without coronary artery disease (CAD) and (ii) its association with mortality in a prospective cohort of patients with CAD.. FVIIa-AT levels were measured by elisa in 686 subjects with (n = 546) or without (n = 140) angiographically proven CAD. Subjects with acute coronary syndromes and those taking anticoagulant drugs at the time of enrollment were excluded. CAD patients were followed for total and cardiovascular mortality.. There was no difference in FVIIa-AT levels between CAD (84.8 with 95% confidence interval [CI] 80.6-88.2 pmol L(-1) ) and CAD-free subjects (83.9 with 95% CI 76.7-92.8 pmol L(-1) ). Within the CAD population, during a 64-month median follow-up, patients with FVIIa-AT levels higher than the median value at baseline (≥ 79 pmol L(-1) ) had a two-fold greater risk of both total and cardiovascular mortality. Results were confirmed after adjustment for sex, age, the other predictors of mortality (hazard ratio for total mortality: 2.05 with 95% CI 1.22-3.45, hazard ratio for cardiovascular mortality 1.94 with 95% CI 1.01-3.73, with a slight improvement of C-statistic over traditional risk factors), FVIIa levels, drug therapy at discharge, and even patients using all the usual medications for CAD treatment. High FVIIa-AT levels also correlated with increased thrombin generation.. This preliminary study suggests that plasma concentration of FVIIa-AT is a thrombophilic marker of total and cardiovascular mortality risk in patients with clinically stable CAD.

Topics: Aged; Anticoagulants; Antithrombins; Coronary Angiography; Coronary Artery Disease; Enzyme-Linked Immunosorbent Assay; Factor VIIa; Female; Follow-Up Studies; Glomerular Filtration Rate; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Proportional Hazards Models; Prospective Studies; Risk Factors; Thrombin; Thromboplastin; Treatment Outcome

Current methods for distinguishing acute coronary syndromes such as heart attack from stable coronary artery disease, based on the kinetics of thrombin formation, have been limited to evaluating sensitivity of well-established chemical species (e.g., thrombin) using simple quantifiers of their concentration profiles (e.g., maximum level of thrombin concentration, area under the thrombin concentration versus time curve). In order to get an improved classifier, we use a 34-protein factor clotting cascade model and convert the simulation data into a high-dimensional representation (about 19000 features) using a piecewise cubic polynomial fit. Then, we systematically find plausible assays to effectively gauge changes in acute coronary syndrome/coronary artery disease populations by introducing a statistical learning technique called Random Forests. We find that differences associated with acute coronary syndromes emerge in combinations of a handful of features. For instance, concentrations of 3 chemical species, namely, active alpha-thrombin, tissue factor-factor VIIa-factor Xa ternary complex, and intrinsic tenase complex with factor X, at specific time windows, could be used to classify acute coronary syndromes to an accuracy of about 87.2%. Such a combination could be used to efficiently assay the coagulation system.

Topics: Acute Coronary Syndrome; Algorithms; Blood Coagulation; Blood Coagulation Factors; Coronary Artery Disease; Decision Trees; Humans; Kinetics; Models, Biological; Molecular Dynamics Simulation; Thrombin; Thromboplastin; Time Factors

Protein-disulphide isomerase family (PDI) are an ER-stress protein that controls TF-procoagulant activity but its role in HVSMC migration and coronary artery disease remains to be elucidated. We aimed to investigate whether in human coronary smooth muscle cells (HVSMC) the ER-stress protein-disulphide isomerase family A member 2 (PDIA2) regulates tissue factor (TF) polarisation during migration and atherosclerotic remodeling. PDIA2 and TF were analysed by confocal microscopy, silenced by small interfering RNAs (siRNA) and their function analysed by transwell and migration assays in vitro and in vivo. PDIA2and TF co-localise in the front edge of motile HVSMC. Silencing PDIA2, as well as silencing TF, reduces migration. PDIA2 silenced cells show increased TF-rich microparticle shedding. In vivo cell-loaded plug implants in nude mice of PDIA2 silenced HVSMC together with microvascular endothelial cells showed a significant impairment in mature microvessel formation. PDIA2 and TF are found in remodelled atherosclerotic plaques but not in healthy coronaries. In conclusion, we demonstrate that TF is chaperoned by PDIA2 to the HVSMC membrane and to the cell migratory front. Absence of PDIA2 impairs TF intracellular trafficking to its membrane docking favoring its uncontrolled release in microparticles. TF-regulated HVSMC migration and microvessel formation is under the control of the ER-protein PDIA2.

Topics: Animals; Cell Membrane; Cell Movement; Cell-Derived Microparticles; Cells, Cultured; Coculture Techniques; Coronary Artery Disease; Coronary Vessels; Endothelial Cells; Humans; Mice, Nude; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Neovascularization, Physiologic; Plaque, Atherosclerotic; Protein Disulfide-Isomerases; Protein Transport; RNA Interference; Signal Transduction; Thromboplastin; Transfection; Vascular Remodeling

Atherosclerotic lesions represent a hypoxic milieu. However, the significance of this milieu in atherothrombosis has not been established. We aimed to assess the hypothesis that vascular wall hypoxia promotes arterial thrombus formation. We examined the relation between vascular wall hypoxia and arterial thrombus formation using a rabbit model in which arterial thrombosis was induced by 0.5 %-cholesterol diet and repeated balloon injury of femoral arteries. Vascular wall hypoxia was immunohistochemically detected by pimonidazole hydrochloride, a hypoxia marker. Rabbit neointima and THP-1 macrophages were cultured to analyse prothrombotic factor expression under hypoxic conditions (1 % O2). Prothrombotic factor expression and nuclear localisation of hypoxia-inducible factor (HIF)-1α and nuclear factor-kappa B (NF-κB) p65 were immunohistochemically assessed using human coronary atherectomy plaques. Hypoxic areas were localised in the macrophage-rich deep portion of rabbit neointima and positively correlated with the number of nuclei immunopositive for HIF-1α and NF-κB p65, and tissue factor (TF) expression. Immunopositive areas for glycoprotein IIb/IIIa and fibrin in thrombi were significantly correlated with hypoxic areas in arteries. TF and plasminogen activator inhibitor-1 (PAI-1) expression was increased in neointimal tissues and/or macrophages cultured under hypoxia, and both were suppressed by inhibitors of either HIF-1 or NF-κB. In human coronary plaques, the number of HIF-1α-immunopositive nuclei was positively correlated with that of NF-κB-immunopositive nuclei and TF-immunopositive and PAI-1-immunopositive area, and it was significantly higher in thrombotic plaques. Vascular wall hypoxia augments the thrombogenic potential of atherosclerotic plaque and thrombus formation on plaques via prothrombotic factor upregulation.

Topics: Aged; Angioplasty, Balloon; Animals; Atherosclerosis; Cell Hypoxia; Cell Line; Cholesterol, Dietary; Coronary Artery Disease; Disease Models, Animal; Female; Femoral Artery; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Macrophages; Male; Middle Aged; Neointima; Plaque, Atherosclerotic; Plasminogen Activator Inhibitor 1; Rabbits; Risk Factors; Signal Transduction; Thromboplastin; Thrombosis; Tissue Culture Techniques; Transcription Factor RelA; Vascular System Injuries

Atherosclerotic plaque thrombogenicity is a critical factor that affects thrombus formation and the onset of acute myocardial infarction (AMI). The aim of this study was to identify the vascular factors involved in thrombus formation and AMI onset.. Culprit lesions in 40 coronary arteries with thrombi at autopsy after lethal AMI and non-cardiac death (asymptomatic plaque disruption) were analyzed on histology. Thrombus size, ratio of thrombus to lumen area, length of plaque disruption, and immunopositive areas for tissue factor (TF) and hexokinase (HK)-II were significantly larger in coronary arteries with AMI than with asymptomatic plaque disruption. The size of coronary thrombus positively correlated with the length of plaque disruption (r=0.80) and with immunopositive areas for TF (r=0.38) and HK-II (r=0.40). Because both M1 and M2 macrophages express TF and HK-II in symptomatic plaques, we assessed TF and HK-II expression in M1- and M2-polarized macrophages. The expression of TF was increased and that of HK-II was decreased in M2-, compared with M1-polarized THP-1 macrophages. Inhibiting glycolysis enhanced TF expression in the macrophages partly via hypoxia inducible factor-1α.. The degree of plaque disruption and expression of TF and HK-II appear to be important vascular factors for AMI onset, and polarized macrophages make a distinct contribution to thrombogenicity and glucose metabolism.

Topics: Autopsy; Case-Control Studies; Cause of Death; Cell Line; Coronary Artery Disease; Coronary Thrombosis; Coronary Vessels; Gene Expression Regulation; Glycolysis; Hexokinase; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Macrophages; Myocardial Infarction; Phenotype; Plaque, Atherosclerotic; Thromboplastin

To develop and evaluate a multicolour flow cytometry method for analysis of microparticles (MPs) in fresh whole blood without any centrifugation steps or freezing/thawing procedure.. Flow cytometry was performed using a FC500 MPL cytometer. The compensation in the protocol was performed based on the platelet population. Polystyrene microspheres 0.50-1.27 μm were used for size position, and the MP gate was set as particles 0.5-1.0 μm. Whole blood was incubated with annexin V and antibodies to tissue factor (TF), platelets (CD41 and CD62P), monocyte (CD14) and endothelial cells (CD144). For comparison, MPs from platelet free supernatant was used. The TF activity was evaluated by Calibrated Automated Thrombogram.. Annexin V was used to distinguish true events from background noise. For standardization, each analysis included 10,000 events in the gate of platelets. There were 622(462-1001) MP(annV+)/10,000 platelets and of these, 66 (49-82)/10,000 platelets expressed TF. After correction for the individual platelet counts, the amount of circulating MP(annV+) was 17.1 (12.1-24.9) × 10(9)/L in whole blood, and of these, 10% (6-12%) expressed TF. The majority of the MPs expressed CD41, and 5.6% (2.2-6.9%) of these co-expressed TF. The amount of CD41 + MP(annV+) tended to correlate to the TF activity in whole blood. There was no correlation between the MP(annV+) in whole blood and MPs derived from platelet free supernatant. Patients with pulmonary arterial hypertension and stable coronary artery disease had increased concentrations of CD41 + MP(annV+) in whole blood.. This multicolour flow cytometry assay in whole blood mimics the in vivo situation by avoiding several procedure steps interfering with the MP count. By standardized quantification of MPs a reference interval of MPs can be created.

Topics: Annexin A5; Antibodies, Monoclonal; Antigens, CD; Blood Platelets; Calibration; Cell-Derived Microparticles; Coronary Artery Disease; Endothelial Cells; Familial Primary Pulmonary Hypertension; Female; Flow Cytometry; Humans; Hypertension, Pulmonary; Male; Microspheres; Middle Aged; Monocytes; Particle Size; Polystyrenes; Reference Values; Thromboplastin

The predictability of the whole-blood tissue factor levels for restenosis after coronary angioplasty is uncertain. We first probed in depth the association between plasma tissue factor concentrations and the development of restenosis after coronary intervention with an animal pathological model.. Thirty pigs were used and their coronary arteries were injured for the dilatation of balloons. Morphological measurements include neointimal area, injury score and the extent of area stenosis. Whole-blood tissue factor levels were measured before and after intervention. The circulating tissue factor levels increased significantly after intervention (baseline value, 328.54 ± 47.46 pg/ml; at 30th minute, 618.96 ± 119.08 pg/ml; at 24th hour, 639.34 ± 116.21 pg/ml) (p < 0.01), and the degrees of tissue factor changes correlated positively to the neointimal hyperplasty (r(30th min) = 0.751, r(24th hour) = 0.72, p < 0.01). There was no significant difference with the baseline whole blood tissue factor (TF) levels between restenotic and non-restenotic cases (330.83 ± 47.32 vs. 325.1 ± 49.57 pg/ml) (p > 0.05). The injury of media led to the most distinctive changes of blood tissue factor (p < 0.01).. Higher values of whole-blood tissue factor may be a predictor of restenosis, and the damaged media might be the main reason of the tissue factor increase.

Topics: Angioplasty, Balloon, Coronary; Animals; Coronary Artery Disease; Coronary Restenosis; Male; Multivariate Analysis; Muscle, Smooth, Vascular; Predictive Value of Tests; Prognosis; Risk Factors; Swine; Thromboplastin; Time Factors

IgG may accelerate atherosclerosis via ligation of proinflammatory Fcγ receptors; however, IgM is unable to ligate FcγR and is often considered vasculoprotective. IgM aggravates ischemia-reperfusion injury, and solid-phase deposits of pure IgM, as seen with IgM-secreting neoplasms, are well known clinically to provoke vascular inflammation. We therefore examined the molecular mechanisms by which immunoglobulins can aggravate vascular inflammation, such as in atherosclerosis. We compared the ability of fluid- and solid-phase immunoglobulins to activate macrophages. Solid-phase immunoglobulins initiated prothrombotic and proinflammatory functions in human macrophages, including NF-κB p65 activation, H(2)O(2) secretion, macrophage-induced apoptosis, and tissue factor expression. Responses to solid-phase IgG (but not to IgM) were blocked by neutralizing antibodies to CD16 (FcγRIII), consistent with its known role. Macrophages from mice deficient in macrophage scavenger receptor A (SR-A; CD204) had absent IgM binding and no activation by solid-phase IgM. RNA interference-mediated knockdown of SR-A in human macrophages suppressed activation by solid-phase IgM. IgM binding to SR-A was demonstrated by both co-immunoprecipitation studies and the binding of fluorescently labeled IgM to SR-A-transfected cells. Immunoglobulins on solid-phase particles around macrophages were found in human plaques, increased in ruptured plaques compared with stable ones. These observations indicate that solid-phase IgM and IgG can activate macrophages and destabilize vulnerable plaques. Solid-phase IgM activates macrophages via a novel SR-A pathway.

Topics: Animals; Blood Coagulation; Cells, Cultured; Complement System Proteins; Coronary Artery Disease; Cytotoxicity, Immunologic; GPI-Linked Proteins; Humans; Hydrogen Peroxide; Immunoglobulin G; Immunoglobulin M; Lipoproteins, LDL; Macrophage Activation; Mice; Muscle, Smooth, Vascular; NF-kappa B; Plaque, Atherosclerotic; Protein Denaturation; Receptors, Fc; Receptors, IgG; Scavenger Receptors, Class A; Signal Transduction; Thromboplastin

Atherosclerotic coronary arteries are more calcified in patients with than without chronic kidney disease (CKD). We addressed the potential for coronary microvascular obstruction in patients with and without CKD during stenting for saphenous vein aorto-coronary graft (SVG) stenosis under protection with a distal occlusion/aspiration device. In patients with and without CKD (n = 20/20), SVG plaque composition was analyzed from virtual histology using intravascular ultrasound analysis before stent implantation. There was more dense calcium and more necrotic core in patients with than without CKD (14 ± 3 vs. 3 ± 1 % and 21 ± 3 vs. 12 ± 2 % of plaque volume, respectively). Coronary aspirate was retrieved during stent implantation and divided into particulate debris and plasma. Patients with CKD had more particulate debris and calcium release than patients without CKD. In contrast, the release of serotonin was less in patients with than without CKD (0.4 ± 0.1 vs. 1.2 ± 0.3 μmol/L), whereas that of catecholamines, endothelin, tissue factor, thromboxane, tumor necrosis factor α, and C reactive protein was not significantly different. Confirming the biochemical results, aspirate plasma from patients with CKD induced less vasoconstriction of rat mesenteric arteries than that from patients without CKD (with endothelium (+E), 26 ± 7 %; without endothelium (-E): 28 ± 7 % vs. +E, 68 ± 12 %; -E: 95 ± 16 % of maximum KCl-induced vasoconstriction). Graft atherosclerosis of patients with CKD is more degenerated and releases more particulate debris and calcium, but the aspirate has surprisingly less serotonin and vasoconstrictor potential.

Topics: Adult; Aged; Aged, 80 and over; alpha-2-HS-Glycoprotein; Animals; Atherosclerosis; Blood Vessel Prosthesis Implantation; C-Reactive Protein; Calcium; Coronary Artery Disease; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Necrosis; Plaque, Atherosclerotic; Rats; Renal Insufficiency, Chronic; Saphenous Vein; Stents; Thromboplastin; Tumor Necrosis Factor-alpha; Ultrasonography, Interventional; Vascular Calcification; Vasoconstriction

A suitable animal model is required to investigate plaque biology. Here, we examined 6 rabbit models of plaque generated by balloon injury and sequential combinations of normal and high-cholesterol diets.. Fifty-eight male Japanese White rabbits were used. Lipid-rich macrophages accumulated in the center of the intima, and smooth muscle cells were located on the luminal side of the intima (similar to stable plaques in human coronary arteries) of a model in which balloon injury was followed by a normal diet for 4 weeks and then by a high-cholesterol diet for 4 weeks. Extending the high-cholesterol diet for a further 4 weeks increased accumulation of lipid-rich macrophages, diminished the amounts of elastic fibers and smooth muscle cells in the intima and caused the expression of matrix metalloproteinase-9 and tissue factor. All of these features are characteristic of unstable plaques. Moreover, quantitative analysis revealed that matrix metalloproteinase-9 expression and elastic-fiber content inversely correlated with statistical significance (R(2) = 0.52, p = 0.0003).. A high-cholesterol diet for 0 to 8 weeks after a normal diet for the first 4 weeks following balloon injury induced various arterial lesions resembling the diffuse intimal thickening, as well as stable and unstable plaques that accumulate in human coronary arteries. The present models might be useful for plaque studies.

Topics: Angioplasty, Balloon, Coronary; Animals; Cell Division; Cholesterol, Dietary; Coronary Artery Disease; Coronary Vessels; Disease Models, Animal; Elasticity; Foam Cells; Humans; Lipids; Liver; Macrophages; Male; Matrix Metalloproteinase 9; Muscle, Smooth, Vascular; Rabbits; Thromboplastin

Heat shock proteins (HSPs) are among the most highly conserved and immunogenic proteins shared by microbial agents and mammals. Human (h) HSP60 is upregulated under stress conditions and serves as a target for cross-reactive cytotoxic HSP-serum-antibodies. The present study evaluates the expressions of hHSP60 and its homologue chlamydial (c) HSP60 in advanced human coronary lesions and correlates intimal tissue-bound HSP expressions with circulating HSP-antibodies. Coronary atherectomy specimens retrieved from 100 primary target lesions of patients with unstable angina (UA; n = 40) or stable angina (SA; n = 60) were assessed immunohistochemically for the presence of hHSP60 and cHSP60. In a subgroup (n = 40), blood samples were tested for anti-Chl. pn.-IgG/IgA-titers and anti-HSP65-antibody titers. Coronary plaques revealed immunoreactive hHSP60 in 55% and cHSP60 in 45% of the lesions. Expression of both HSP homologues was significantly (each p < 0.001) higher in UA lesions compared with SA lesions (7.4 vs. 1.2% and 6.0 vs. 1.1%). HSP homologues showed positive correlations both in UA- and SA-lesions (r = 0.41, 0.33; p < 0.05). cHSP60 showed no association with anti-Chl. pn.-IgG/IgA-titers, whereas expressions of both homologues correlated positive with anti-HSP65-Ab titers (r = 0.42, p < 0.05; r = 0.50, p < 0.01). Intimal amounts of HSP60 homologues were associated with increased expressions of C-reactive protein, Toll-like receptor-4 and tissue factor. Human and chlamydial HSP60 colocalize within coronary atheroma, most prevalent in lesions associated with UA. Our data demonstrate a significant correlation between the intimal expressions of HSP60 homologues and serum HSP65 antibodies, thereby suggesting that humoral immune reactions may play an important role in coronary atherosclerosis and plaque instability.

Topics: Aged; Angina, Unstable; Antibodies; C-Reactive Protein; Chaperonin 60; Coronary Artery Disease; Female; Heat-Shock Proteins; Humans; Immunohistochemistry; Male; Middle Aged; Thromboplastin; Toll-Like Receptor 4

Type 2 diabetes mellitus (T2DM) is associated with increased coagulability and vascular complications. Circulating microparticles (MPs) are involved in thrombosis, inflammation, and angiogenesis. However, the role of MPs in T2DM vascular complications is unclear. We characterised the cell origin and pro-coagulant profiles of MPs obtained from 41 healthy controls and 123 T2DM patients with coronary artery disease, retinopathy and foot ulcers. The effects of MPs on endothelial cell coagulability and tube formation were evaluated. Patients with severe diabetic foot ulcers expressed the highest levels of MPs originated from platelet and endothelial cells and negatively-charged phospholipid-bearing MPs. MP coagulability, calculated from MP tissue factor (TF) and TF pathway inhibitor (TFPI) ratio, was low in healthy controls and in diabetic retinopathy patients (<0.7) but high in patients with coronary artery disease and foot ulcers (>1.8, p≥0.002). MPs of all T2DM patients induced a more than two-fold increase in endothelial cell TF (antigen and gene expression) but did not affect TFPI levels. Tube networks were longest and most stable in endothelial cells that were incubated with MPs of healthy controls, whereas no tube formation occurred in MPs of diabetic patients with coronary artery disease. MPs of diabetic retinopathy and diabetic foot ulcer patients induced branched tube networks that were unstable and collapsed over time. This study demonstrates that MP characteristics are related to the specific type of vascular complications and may serve as a bio-marker for the pro- coagulant state and vascular pathology in patients with T2DM.

Topics: Aged; Blood Coagulation; Case-Control Studies; Cell-Derived Microparticles; Coronary Artery Disease; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Foot; Diabetic Retinopathy; Endothelial Cells; Female; Gene Expression; Humans; Lipoproteins; Male; Middle Aged; Neovascularization, Pathologic; Platelet Activation; Thromboplastin

Atrial fibrillation (AF) is a common complication of coronary artery bypass grafting (CABG). We sought to determine the diagnostic validity of plasma biomarkers of i) inflammation (marked by interleukin-6 [IL-6] and high-sensitivity C-reactive protein [hs-CRP]), ii) extracellular matrix remodelling (matrix metalloproteinase [MMP-9], tissue inhibitor of matrix metalloproteinase [TIMP-1]) and iii) the prothrombotic state (tissue factor and von Willebrand factor [vWF]) in the risk prediction of post-operative AF. Samples were obtained preoperatively from peripheral/femoral vein and from intracardiac chambers (right atrium [RA], the right atrial appendage [RAA], the left atrium [LA] and the left atrial appendage [LAA]) amongst 100 consecutive patients free of AF and inflammatory disease undergoing elective CABG. Biomarker concentrations were related to incident AF (30 days). At 30 days post CABG, 30 patients were proven to have had AF. Concentrations of tissue factor (TF) and vWF were unrelated to postoperative AF. Peripheral (p=0.018), and intracardiac levels (RAA (p=0.029) and LA (p=0.026)) of hs-CRP were associated with the presence of AF after CABG. Intracardiac levels of IL-6 in samples from the RAA (p=0.031), LA (p=0.042) and LAA (p=0.006), and MMP-9 in the LAA sample were also associated with AF (p=0.007). Our data suggest that an intra-cardiac inflammatory environment that is manifest peri-operatively may predispose to the development of post-operative AF. This intracardiac inflammatory state was reflected by increased peripheral hs-CRP levels. These differences may indicate local substrate abnormalities contributing to the development of AF post-operatively.

Topics: Aged; Atrial Fibrillation; Biomarkers; C-Reactive Protein; Coronary Artery Bypass; Coronary Artery Disease; Female; Humans; Inflammation; Interleukin-6; Male; Matrix Metalloproteinase 9; Middle Aged; Postoperative Complications; Predictive Value of Tests; Prognosis; Reproducibility of Results; Thromboplastin

The association between periodontal and cardiovascular disease has received considerable attention. Studies have demonstrated a higher incidence of atherosclerotic complications in patients with periodontal disease. Tissue factor (TF) has been known as a key initiator of the coagulation cascade, and the TF pathway is the primary physiological mechanism of initiation of blood coagulation. Recently, it has been shown that the circulating pool of TF in blood is associated with increased blood thrombogenicity in patients with coronary artery disease (CAD). Various tissues and saliva have been known to have TF activity. Consequently, the aim of this study was to investigate plasma TF levels and TF activity of saliva in periodontitis patients with and without diagnosed CAD. Twenty-six patients with a diagnosis of CAD and 26 systemically healthy patients were examined in the dental clinic, and the Community Periodontal Index Treatment Needs (CPITN) scores were recorded. Plasma TF levels were determined using commercially available ELISA kit. Salivary TF activities were determined according to Quick's one-stage method. Plasma TF levels were significantly increased in patients with CAD when compared with the control group. There was no difference in salivary TF activities between the 2 groups, but there was a strong and negative correlation between salivary TF activities and CPITN indexes in both groups. In order to determine the possible role of TF activity as a salivary marker in CAD and periodontitis and to fully understand the negative correlation between salivary TF activities and CPITN, TF activity of gingival crevicular fluid that may also affect saliva can be evaluated.

Topics: Adult; Aged; Aged, 80 and over; Coronary Artery Disease; Female; Humans; Male; Middle Aged; Periodontitis; Saliva; Thromboplastin

Enhanced expression of tissue factor (TF) may result in thrombosis contributing to acute clinical consequences of coronary artery disease. Several studies demonstrated elevated plasma levels of TF in patients with acute coronary syndrome (ACS). The aim of our study was to compare the concentrations of TF in coronary sinus (CS), proximal part of the left coronary artery (LCA) and peripheral vein (PV) of patients with ACS and stable coronary artery disease (SCAD). Time course of the TF plasma levels in PV was followed on day 1 and day 7 after index event of ACS presentation and was compared to day 0 values. No heparin was given prior to the blood sampling. Twenty-nine patients in the ACS group (age 63.6+/-10.8 years, 20 males, 9 females) and 24 patients with SCAD (age 62.3+/-8.1 years, 21 males, 3 females) were examined. TF plasma level was significantly higher in patients with ACS than in those with SCAD (239.0+/-99.3 ng/ml vs. 164.3+/-114.2 ng/ml; p=0.016). There was no difference in TF plasma levels in PV, CS and LCA (239.0+/-99.3 ng/ml vs. 253.7+/-131.5 ng/ml vs. 250.6+/-116.4 ng/ml, respectively). TF plasma levels tended to decrease only non-significantly on the day 7 (224.4+/-109.8 ng/ml). Significant linear correlation between TF and high sensitivity CRP (hs-CRP) levels on day 0 was found. In conclusion, TF plasma levels are elevated in patients with ACS not only locally in CS but also in systematic circulation. Our data support the relationship between TF production and proinflammatory mediators.

Topics: Acute Coronary Syndrome; Aged; Coronary Artery Disease; Coronary Sinus; Female; Humans; Male; Middle Aged; Thromboplastin

Topics: Chemistry Techniques, Analytical; Coronary Artery Disease; Humans; Thromboplastin

Interleukin-6 (IL-6) and tissue factor (TF) are elevated after myocardial ischemia during dobutamine stress echo (DSE). We examined the incremental prognostic value of IL-6 or TF measured during DSE over echocardiographic and clinical factors in patients with chronic coronary artery disease (CAD).. We studied 106 patients with angiographically documented CAD. IL-6 and TF were measured at rest, peak, and during recovery. A wall motion score index was calculated.. Fifty-seven (54%) patients had ischemia at DSE. During follow-up (63.7 +/- 20 months), 36 patients (33%) had an adverse event (12 cardiac deaths, 24 acute coronary events). Patients with events had a higher peak IL-6 (P = .02) but similar rest and recovery IL-6 than those without. Patients with peak IL-6 > or =3.14 pg/mL (upper tertile) had a hazard ratio of 2.7 (95% CI 1.44-5.37) (P < .01 for an adverse event). The addition of peak wall motion score index in a multivariable model including risk factors, ejection fraction, revascularization, and multivessel disease increased the model's c statistic from 0.66 to 0.70 (P = .04). The addition of peak IL-6 further increased the model's c statistic to 0.75 (P = .04). Tissue factor was not related with cardiac events.. Interleuikin-6 levels measured during the peak phase of DSE incrementally contribute to risk stratification in patients with chronic CAD.

Topics: Aged; Cardiac Catheterization; Coronary Artery Disease; Echocardiography, Stress; Female; Follow-Up Studies; Humans; Interleukin-6; Kaplan-Meier Estimate; Male; Middle Aged; Multivariate Analysis; Prognosis; Proportional Hazards Models; ROC Curve; Thromboplastin

It has been established that inflammation and enhanced pro-coagulant activity are associated with the pathogenesis of atherosclerotic vascular disease. We evaluated and compared the contributions of the factor (F)XIa and tissue factor (TF) activity in plasma of patients with coronary artery disease (CAD). Citrate plasma was obtained prior to therapy from 53 patients with stable angina (29 with a history of previous myocardial infarction; CAD-MI) and 30 with acute coronary syndrome (ACS) within 12 hours from pain onset. Four ACS patients treated with heparin were excluded. FXIa and TF activity were determined in clotting assays based upon the prolongation of clotting time by inhibitory monoclonal antibodies. Twenty-five of 26ACS patients (96%) and 22 of 29 CAD-MI patients (76%) had quantifiable FXIa (50 +/- 33 and 42 +/- 45pM, respectively). Ten of 26 (38%) ACS patients and only three of 53 (6%) stable CAD patients showed TF activity (<0.4pM). No FXIa or TF activity was observed in age-matched healthy controls (n = 12). For both CAD-MI and ACS patients, there were correlations (p < 0.05) between FXIa and interleukin-6 (R(2) = 0.59 and 0.39, respectively) and between FXIa and TAT (R(2) = 0.64 and 0.63, respectively). In conclusion, the majority of ACS and CAD-MI patients have circulating FXIa that correlates with markers of coagulation and inflammation.

Topics: Acute Coronary Syndrome; Aged; Angina Pectoris; Antithrombin III; Biomarkers; Blood Coagulation; Blood Coagulation Tests; Case-Control Studies; Coronary Artery Disease; Factor Xa; Humans; Inflammation; Interleukin-6; Male; Middle Aged; Myocardial Infarction; Peptide Hydrolases; Thromboplastin

Topics: Angina Pectoris; Biomarkers; Blood Coagulation; Cardiovascular Diseases; Coronary Artery Disease; Humans; Lipoproteins; Myocardial Ischemia; Predictive Value of Tests; Prognosis; Risk Assessment; Severity of Illness Index; Thromboplastin

Tissue factor (TF), the initiator of coagulation, circulates in blood and contributes to thrombosis in patients with coronary artery disease (CAD). TF is present in the alpha-granules of platelets. Therapy with clopidogrel results in inhibition of platelet degranulation. Whether clopidogrel affects circulating TF is unknown. This study examined the effect of clopidogrel on TF level in the blood of patients with stable CAD and ST-elevation myocardial infarction (STEMI) as well as healthy controls.. Thirty-three patients with CAD and twenty with STEMI were studied pre and post clopidogrel therapy (loading dose 300 mg, then 75 mg daily). All were treated with aspirin 100 mg/d. The control groups consisted of thirty healthy male volunteers also treated with clopidogrel and ten patients with CAD treated with aspirin only. TF concentration in blood drawn pre and 96 h post clopidogrel administration was measured by enzyme-linked immunosorbent assay.. Patients with CAD and STEMI had significantly more TF in blood than healthy controls. Clopidogrel reduced TF in stable CAD patients to levels seen in healthy controls. No alterations in TF were found in controls and patients with STEMI post clopidogrel therapy. Clopidogrel reduced sCD40L level in stable CAD patients, but not in STEMI patients. A correlation between TF and sCD40L was found for the combined CAD and control, but not STEMI group.. Clopidogrel leads to a reduction of not only sCD40L but also TF in stable CAD. The reduction of TF may lead to a reduced thrombogenicity, contributing to the benefits of clopidogrel therapy.

Topics: Adult; CD40 Ligand; Clopidogrel; Coronary Artery Disease; Female; Humans; Male; Middle Aged; Myocardial Infarction; Platelet Aggregation Inhibitors; Solubility; Thromboplastin; Ticlopidine; Treatment Outcome

Although serum amyloid A (SAA) is a useful biomarker of coronary artery disease (CAD), its direct role in procoagulation is obscure. This study investigates the impact of SAA on the expression and activity of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in endothelial cells.. SAA was found to disturb the balance of TF and TFPI expression and activity in human endothelial cells. SAA (20 microg/mL) markedly induced TF expression between 4 to 8 hours in both protein and mRNA levels, as well as TF activity. Conversely, incubation of SAA (20 microg/mL) for 24 and 48 hours was found to significantly inhibit TFPI secretion, transcription, and activity. Pretreatment with formyl peptide receptor-like 1 (FPRL1) inhibitors (Pertussis toxin and WRWWWW) could block the SAA effects on TF and TFPI. Furthermore, pretreatment with the respective specific mitogen-activated protein kinase (MAPK) inhibitors (SB203580, PD98059, and SP600125) and NFkappaB inhibitor (Bay-11 to 7082) could block SAA-dependent TF induction. SAA also directly induced activation of MAP kinases and NFkappaB.. The stimulating effect of SAA was faster-acting on the expression and activity of TF and the inhibitory effect was slower-acting on TFPI. The effects are mediated through FPRL1, MAP kinases and NFkappaB.

Topics: Blotting, Western; Cells, Cultured; Coronary Artery Disease; Coronary Vessels; Endothelial Cells; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Humans; Lipoproteins; Probability; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Serum Amyloid A Protein; Thromboplastin; Umbilical Veins

Topics: Aged; Coronary Artery Disease; Female; Fibrin Fibrinogen Degradation Products; Humans; Lipoprotein(a); Lipoproteins; Male; Middle Aged; Severity of Illness Index; Thromboplastin

Elevated plasma C-reactive protein (CRP) levels predict coronary events, but it is unclear whether CRP plays a role in thrombosis associated with these events. We investigated tissue factor (TF) induction by CRP on peripheral blood mononuclear cells (PBMC) from patients with coronary disease.. PBMC from 35 patients with stable angina (SA) in study 1, 10 male patients with SA, 10 with unstable angina (UA) and 10 matched controls in study 2, and 25 patients with inflammatory disorders (ID) and 24 normal controls in study 3 were stimulated with CRP, interferon-gamma (IFN) or lipopolysaccharide (LPS), or their combination. PBMC from additional normal donors were also stimulated with CRP in adherent and non-adherent conditions, and TF activity, antigen and mRNA expression detected.. CRP (5-25 microg mL(-1)) dose dependently induced more TF on PBMC from SA patients than 42 contemporary controls (P = 0.001, study 1). Compared with controls, patients with SA or UA had higher basal, and much higher CRP- or CRP/LPS-induced monocyte TF activity although serum CRP levels were similar (study 2). IFN induced monocyte TF activity in patients with angina, but not in controls. Basal or CRP-induced TF levels did not differ between controls and ID, even though ID patients had much higher serum CRP levels (study 3). CRP-induced monocyte TF activity correlated with serum CRP levels in controls (P = 0.005) and ID (P = 0.007) in study 3, but not in patients with angina (P =0.84) in study 2. CRP induced more TF activity, protein and mRNA under adherent than non-adherent conditions implying that it may mainly target macrophages in lymphocyte-rich lesions.. Our results indicate that monocytes from patients with angina are preactivated and express TF but CRP is unlikely to be a major priming factor in vivo. IFN and CRP further increase TF levels that may contribute to the hypercoagulable state in coronary disease.

Topics: Adult; Aged; Angina Pectoris; C-Reactive Protein; Case-Control Studies; Cells, Cultured; Coronary Artery Disease; Dose-Response Relationship, Drug; Female; Gene Expression Regulation; Humans; Interferon-gamma; Leukocytes, Mononuclear; Lipopolysaccharides; Male; Middle Aged; Thrombophilia; Thromboplastin

Tissue factor (TF) has been implicated in coronary artery disease (CAD). High levels of circulating TF are found in patients with acute atherothrombotic events. Whether high serum TF levels predict risk of future CAD independent of known risk factors remains unknown.. We conducted a prospective case-control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk population study. Cases (n=1037) were apparently healthy men and women, aged 45-79 years, who developed fatal or non-fatal CAD during follow-up. Controls (n=2005) were matched by age, sex, and enrolment time. Serum TF levels were measured using high-affinity antibodies.. In men, median TF levels were not significant higher in cases than in controls (59.0 pg mL-1, range: 16.7-370.4 vs. 54.9 pg mL-1, range: 16.2-452.4). In women, median TF levels were not significant higher in controls than in cases (73.4 pg mL-1, range: 16.7-492.3 vs. 50.5 pg mL-1, range: 16.5-376.7). The incidence of smoking was about double in the lowest compared with the highest TF quartile. Correcting for sex, age, body mass index, smoking, diabetes, systolic blood pressure, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol and C-reactive protein levels, the risk of future CAD was 1.05 (95% CI: 0.81-1.36) for people in the highest TF quartile, compared with those in the lowest (P-value for linearity=0.8).. High levels of serum TF were not independently associated with an increased risk of future CAD in apparently healthy individuals.

Topics: Aged; Blood Pressure; C-Reactive Protein; Case-Control Studies; Coronary Artery Disease; Female; Follow-Up Studies; Humans; Incidence; Lipoproteins, HDL; Lipoproteins, LDL; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Risk Factors; Smoking; Thromboplastin

To determine the proportion of platelets and fibrin in coronary thrombi.. Immunohistochemical and morphometric means to examine the coronary arteries of 31 patients who died of acute myocardial infarction.. Fresh thrombi were detected in the feeding arteries of infarction areas in 23 cases (74%) and were associated with plaque rupture in 18 (78%) and plaque erosion in 5 (22%). An immunohistochemical study showed that the thrombi consisted of a mixture of fibrin and platelets as well as some other types of blood cells. The fibrin and platelet positive areas in the thrombi associated with plaque rupture accounted for 74 (19)% and 35 (20)% (p < 0.01) and those associated with erosion accounted for 51 (6)% and 70 (21)%, respectively, of the total areas. Areas of positive immunoreactivity for tissue factor and C reactive protein were also significantly greater in ruptured than in eroded plaques.. These results indicate that the proportions of fibrin and of platelets differ in coronary thrombi on ruptured and eroded plaques. Higher proportions of tissue factor and C reactive protein contribute more significantly to thrombus formation on plaque rupture than on plaque erosion.

Topics: Aged; Aged, 80 and over; Biomarkers; Blood Platelets; C-Reactive Protein; Coronary Artery Disease; Coronary Thrombosis; Female; Fibrin; Humans; Male; Middle Aged; Risk Factors; Thromboplastin

Topics: Biomarkers; Coronary Artery Disease; Echocardiography, Stress; Humans; Interleukin-6; Myocardial Ischemia; Predictive Value of Tests; Thromboplastin

To explore whether normal platelet contains tissue factor (TF), and the significance of platelet-associated TF (PATF).. Platelets were isolated by Sepharose 2B gel column. ELISA was used to detect the TF content in the lysates of washed platelets. Procoagulant activity of PATF was measured by one stage clotting time assay. The mRNA of TF was detected by reverse transcription polymerase chain reaction (RT-PCR).. A certain amount of TF antigen (16.37 +/- 6.39) ng/L was detected in the washed-platelet lysates. Upon activation by collagen, platelets released TF and caused a marked increase in TF level in plasma (P <0.05). Resting platelets had no TF procoagulant activity, while procoagulant activity of platelets activated by collagen increased significantly, which could be blocked by TF McAb and poor VII plasma. TF mRNA could not be detected in washed platelets. TF content in platelets from patients with coronary heart disease was significantly higher than that from normal controls (P < 0.05). Resting platelets from the patients showed a higher procoagulant activity, which could be inhibited by TF McAb.. Platelets contain TF and the latter released by activated platelet was functionally active. Platelet itself might not synthesize TF. Protein content and procoagulant activity of PATF in patients with coronary heart disease were higher than that in controls. All these indicate that platelet may be involved in coagulation and thrombosis by releasing TF.

Topics: Adolescent; Adult; Blood Platelets; Coronary Artery Disease; Female; Humans; Male; Middle Aged; Platelet Activation; Thromboplastin

Matrix metalloproteinases (MMPs) cause extracellular matrix degradation and may be involved in the rupture of atherosclerotic plaques by degrading fibrous cap, resulting in the intravascular thrombus formation. Here we examined whether local overexpression of MMP-9 alters the characteristics of arteriosclerotic vascular lesions and promotes thrombosis after balloon injury in porcine coronary arteries in vivo.. Balloon angioplasty was performed in the left coronary arteries followed by injection of adenovirus vector solution encoding either MMP-9 or beta-galactosidase (beta-gal) gene into the injured coronary arteries. Three weeks after the gene transfer, histological examination demonstrated that macroscopic intravascular thrombus formation was noted at the MMP-9-transfected site but not at the beta-gal-transfected site. Microscopic intramural thrombus area was significantly larger at the MMP-9-transfected site as compared to the beta-gal-transfected site. Co-transfection of tissue inhibitor of metalloproteinase-1 (TIMP-1) with MMP-9 prevented the intravascular thrombus formation in vivo. Western blot analysis revealed the reduced expression of intact tissue factor pathway inhibitor-1 and the increased tissue factor (TF) expression at the MMP-9-transfected sites.. These results provide the first in vivo evidence that overexpression of MMP-9 promotes intravascular thrombus formation after balloon injury due in part to the activation of TF-mediated coagulation cascade.

Topics: Adenoviridae; Angioplasty, Balloon, Coronary; Animals; Coronary Artery Disease; Coronary Thrombosis; Genetic Vectors; Lipoproteins; Male; Matrix Metalloproteinase 9; Swine; Thromboplastin; Tissue Inhibitor of Metalloproteinase-1; Transfection

Thrombogenesis, angiogenesis, and endothelial damage/dysfunction are components in the pathogenesis of atherosclerosis.. To investigate the relation of these variables to atherosclerotic disease severity and the possible interrelations between the three.. 111 patients attending for coronary angiography were studied (85 male, 26 female; mean (SD) age, 61.6 (10.0) years). Plasma concentrations of von Willebrand factor (vWf, a marker of endothelial damage/dysfunction), vascular endothelial growth factor (VEGF, associated with angiogenesis), soluble VEGF receptor Flt-1 (sFlt-1), and tissue factor (TF, a key component of coagulation) were measured by an enzyme linked immunosorbent assay. Following angiography, disease severity was assessed by the number of coronary vessels diseased (> 50% stenosis) and by a coronary atheroma score.. All indices were raised in the patients compared with 34 healthy controls except sFlt-1, which was lower in the patients. No significant correlations were found between the coronary atheroma score and values of vWf (Spearman correlations: r = 0.21, p = 0.83), VEGF (r = 0.11, p = 0.27), or TF (r = -0.04, p = 0.68). However, there was an inverse correlation between plasma sFlt-1 and coronary atheroma score (r = -0.19, p = 0.049). The number of vessels diseased had no relation to any marker. Correlations were found between TF and VEGF (r = 0.25, p = 0.008) and between TF and sFlt-1 (r = 0.42, p < 0.001) in the patients.. Despite evidence of abnormal angiogenesis (VEGF and sFlt-1), thrombogenesis (TF), and endothelial damage/dysfunction (vWf) in the patients with coronary artery disease, there was no correlation between VEGF, sFlt-1, vWf, or TF and angiographically defined disease severity.

Topics: Coronary Angiography; Coronary Artery Disease; Coronary Thrombosis; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Neovascularization, Pathologic; Regression Analysis; Risk Factors; Thromboplastin; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1; von Willebrand Factor

The tissue factor plays a crucial role in initiating blood coagulation after plaque rupture in patients with acute coronary syndrome. It is abundant in atherosclerotic plaques. Moreover, P-selectin, some cytokines, endotoxin and immune complexes can stimulate monocytes and induce the tissue factor expression on their surface. The aim of the study was to compare plasma levels of the tissue factor, tissue factor pathway inhibitor, P-selectin, E-selectin and ICAM-1 in patients with acute myocardial infarction, unstable angina pectoris, stable coronary artery disease and normal control subjects. In addition, plasma levels of the tissue factor, tissue factor pathway inhibitor, P-selectin, E-selectin and ICAM-1 were measured in the blood withdrawn from the coronary sinus in a subgroup of patients with unstable angina pectoris and stable coronary artery disease in which the difference between concentrations in the coronary sinus and systemic blood was calculated. A significant increase in tissue factor pathway inhibitor plasma levels was detected in patients with acute myocardial infarction (373.3+/-135.1 ng/ml, p<0.01) and unstable angina pectoris (119.6+/-86.9 ng/ml, p<0.05) in contrast to the patients with stable coronary artery disease (46.3+/-37.5 ng/ml) and normal subjects (45.1+/-14.3 ng/ml). The plasma levels of tissue factor pathway inhibitor were significantly increased both in the coronary sinus and systemic blood in the patients with unstable angina pectoris. There was only a non-significant trend to higher plasma levels of the tissue factor in patients with acute myocardial infarction and unstable angina pectoris as compared to the patients with stable coronary artery disease and normal subjects, the values being 129.1+/-30.2 pg/ml, 130.5+/-57.8 pg/ml, 120.2+/-45.1 pg/ml and 124.9+/-31.8 pg/ml, respectively. Plasma levels of soluble P-selectin was only slightly, but non-significantly higher in patients with unstable angina pectoris and stable coronary artery disease (184.2+/-85.4 ng/ml and 201.6+/-67.9 ng/ml, respectively) than in patients with the acute myocardial infarction (157.4+/-88.4 ng/ml) or normal subjects (151.4+/-47.1 ng/ml). The difference in plasma levels of soluble ICAM-1 between the blood withdrawn from the coronary sinus and systemic circulation correlated significantly with the corresponding difference in plasma levels of soluble P-selectin and E-selectin. In conclusion, the tissue factor and the tissue factor pathway inhibitor play

Topics: Adult; Aged; Angina, Unstable; Cell Adhesion Molecules; Coronary Artery Disease; E-Selectin; Female; Humans; Intercellular Adhesion Molecule-1; Linear Models; Lipoproteins; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; P-Selectin; Thromboplastin

Topics: Arteriosclerosis; Coronary Artery Disease; Coronary Thrombosis; Disease Progression; Endothelium, Vascular; Humans; Magnetic Resonance Imaging; Risk Factors; Thromboplastin; Vasa Vasorum

Monocytes play a prominent role in inflammation, coagulation and atherosclerosis by their ability to produce tissue factor (TF) and cytokines. The aim of the present study was to establish whether virus-infected monocytes initiate coagulation. In addition, the production of cytokines by monocytes may accelerate the chronic process of atherosclerosis and may contribute to coronary syndromes by eliciting plaque instability.. Monocytes were isolated by Vacutainer(R), BD Biosciences, Alphen aan den Rijn, Netherlands and subsequent magnetic cell sorting (MACS(R), Milteny Biotec, Bergish Gladbach, Germany). Coagulation times in normal pooled plasma and Factor VII-deficient plasma were measured after infection with cytomegalovirus (CMV), Chlamydia pneumoniae (Cp) and influenza A\\H1N1. Anti-TF antibodies were added to neutralize TF expressed on monocytes. Interleukins (IL) 6, 8 and 10 were measured in the supernatants.. Chlamydia pneumoniae- and CMV-infected monocytes decreased the clotting time by 60%, and influenza-infected monocytes by 19%, as compared to uninfected monocytes. Procoagulant activity was absent when Factor VII-deficient plasma or anti-TF antibodies were used. Monocytes produced both IL-6 and IL-8 after infection with CMV (317 pg mL-1 and 250 pg mL-1) or Cp (733 pg mL-1 and 268 pg mL-1). Similar results were obtained for influenza virus-infected monocytes, but the levels of both cytokines were 3-5-fold higher (1797 pg mL-1 and 725 pg mL-1). Interleukin-10 was not produced by infected monocytes.. The procoagulant activity of virus-infected monocytes is TF-dependent. Although influenza infection did not generate a significant reduction in clotting time, the pronounced expression of IL-6 and IL-8 may induce local and/or systemic inflammatory reactions, which may be associated with plaque rupture and atherosclerosis. The lack of production of the anti-inflammatory cytokine IL-10 may even accelerate these processes.

Topics: Antibodies; Chlamydophila Infections; Coronary Artery Disease; Cytomegalovirus Infections; Humans; Influenza A virus; Influenza, Human; Interleukin-10; Interleukin-6; Interleukin-8; Monocytes; Thromboplastin; Virus Diseases; Whole Blood Coagulation Time

Defined angiographically, no-reflow (NR) manifests as an acute reduction in coronary flow in the absence of epicardial vessel obstruction. One candidate protein to cause coronary NR is tissue factor (TF), which is abundant in atherosclerotic plaque and a cofactor for activated plasma coagulation factor VII. Scrapings from atherosclerotic carotid arteries contained TF activity (corresponding to 33.03 +/- 13.00 pg/cm(2) luminal plaque surface). Active TF was sedimented, indicating that TF was associated with membranes. Coronary blood was drawn from 6 patients undergoing coronary interventions with the distal protection device PercuSurge GuardWire (Traatek, Miami, FL). Fine particulate material that was recovered from coronary blood showed TF activity (corresponding to 91.1 +/- 62.16 pg/mL authentic TF). To examine the role of TF in acute coronary NR, blood was drawn via a catheter from coronary vessels in 13 patients during NR and after restoration of flow. Mean TF antigen levels were elevated during NR (194.3 +/- 142.8 pg/mL) as compared with levels after flow restoration (73.27 +/- 31.90 pg/mL; P =.02). To dissect the effects of particulate material and purified TF on flow, selective intracoronary injection of atherosclerotic material or purified relipidated TF was performed in a porcine model. TF induced NR in the model, thus strengthening the concept that TF is causal, not just a bystander to atherosclerotic plaque material. The data suggest that active TF is released from dissected coronary atherosclerotic plaque and is one of the factors causing the NR phenomenon. Thus, blood-borne TF in the coronary circulation is a major determinant of flow.

Topics: Angioplasty; Animals; Blood Flow Velocity; Carotid Stenosis; Coronary Artery Disease; Coronary Circulation; Hemostasis; Humans; Immunohistochemistry; Injections, Intra-Arterial; Models, Animal; Stents; Swine; Thromboplastin

Topics: Angina Pectoris; Angioplasty, Balloon, Coronary; Animals; Anticoagulants; Blood Vessels; Coronary Artery Disease; Factor Xa Inhibitors; Humans; Lipoproteins; Recombinant Proteins; Recurrence; Thromboplastin; Thrombosis

Higher levels of tissue factor (the initiator of blood coagulation) have been found in coronary atherosclerotic plaques of patients with unstable coronary artery disease, but it is not established whether they are associated with a different thrombotic response to in vivo plaque rupture. In 40 patients undergoing directional coronary atherectomy, prothrombin fragment 1 + 2, a marker of thrombin generation, was measured in intracoronary blood samples obtained proximally and distally to the coronary atherosclerotic plaque before and after the procedure. Before the procedure, plasma prothrombin fragment 1 + 2 levels were significantly increased across the lesion in patients with unstable, but not in those with stable, coronary disease (unstable, median increase, 0.37 nM; range, -0.35-1.16 nM) (stable, median increase, -0.065 nM; range, -0.58-1.06 nM) (P =.0021). After plaque removal, an increase in prothrombin fragment 1 + 2 across the lesion was observed only in patients with unstable coronary disease (unstable, median increase, 0.25 nM; range, -1.04-4.9 nM) (stable, 0.01 nM; range, -0.48-3.59 nM) (P =.036)]. There was a correlation between the tissue factor content of the plaque and the increase in thrombin generation across the lesion (rho = 0.33; P =.038). The higher tissue factor content found in plaques obtained from patients with unstable coronary disease was associated with a local increase in thrombin generation, thus suggesting a link with the in vivo thrombogenicity of the plaque.

Topics: Aged; Atherectomy, Coronary; Coronary Artery Disease; Female; Hemostatics; Humans; Male; Middle Aged; Peptide Fragments; Prospective Studies; Prothrombin; Radiography; Risk Factors; Thrombin; Thromboplastin; Thrombosis

Apoptotic microparticles are responsible for almost all tissue factor activity of the plaque lipid core. We hypothesized that elevated levels of procoagulant microparticles could also circulate in the peripheral blood of patients with recent clinical signs of plaque disruption and thrombosis.. We studied 39 patients with coronary heart disease, including 12 patients with stable angina and 27 patients with acute coronary syndromes (ACS), and 12 patients with noncoronary heart disease. We isolated the circulating microparticles by capture with annexin V and determined their procoagulant potential with a prothrombinase assay. The cell origins of microparticles were determined in an additional 22 patients by antigenic capture with specific antibodies. The level of procoagulant microparticles did not differ between stable angina patients and noncoronary patients (10.1+/-1.6 nmol/L phosphatidylserine [PS] equivalent versus 9.9+/-1.6 nmol/L PS equivalent, respectively). However, procoagulant microparticles were significantly elevated in patients with ACS (22.2+/-2.7 nmol/L PS equivalent) compared with other coronary (P<0.01) or noncoronary (P<0.01) patients. Microparticles of endothelial origin were significantly elevated in patients with ACS (P<0.01), which suggests an important role for endothelial injury in inducing the procoagulant potential.. High levels of procoagulant endothelial microparticles are present in the circulating blood of patients with ACS and may contribute to the generation and perpetuation of intracoronary thrombi.

Topics: Acute Disease; Angina Pectoris; Antigens, CD; Apoptosis; CD146 Antigen; Coronary Artery Disease; Coronary Thrombosis; Endothelium, Vascular; Female; Humans; Male; Membrane Glycoproteins; Middle Aged; Neural Cell Adhesion Molecules; Phosphatidylserines; Platelet Endothelial Cell Adhesion Molecule-1; Prospective Studies; Receptors, Cell Surface; Thrombophilia; Thromboplastin

Elevated plasma levels of C-reactive protein (CRP) in population studies and in patients with unstable coronary syndromes are predictive of future adverse events, including cardiac death and myocardial infarction, implicating inflammation in pathogenesis. Although CRP is considered a marker of inflammation, it induces monocyte tissue factor (TF) and may play a prothrombotic role in atherosclerosis and its complications.. Peripheral blood mononuclear cells (PBMCs) from 79 healthy men and women aged 26 to 83 years and 21 healthy postmenopausal women taking hormone replacement therapy (HRT) were stimulated with CRP, lipopolysaccharide (LPS), interferon-gamma (IFN), or their combination. Levels of CRP in the normal range (1 to 5 microg/mL) increased basal monocyte TF 4- to 6-fold and 40-fold at higher concentrations (25 microg/mL). Coincubation of LPS with CRP produced a greater-than-additive response. IFN did not induce TF but synergized with CRP to approximately double activity. There was a striking positive correlation between age and monocyte TF induction, with a dramatic rise on monocytes from postmenopausal women that was not apparent on cells from women taking HRT.. Synergy between CRP and inflammatory mediators may play a direct prothrombotic role in the pathogenesis of coronary atherosclerosis and its acute complications by increasing monocyte/macrophage TF. This may contribute to age and sex differences in coronary events and to the protective effects of HRT.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Analysis of Variance; C-Reactive Protein; Coronary Artery Disease; Drug Synergism; Female; Hormone Replacement Therapy; Humans; Inflammation; Interferon-gamma; Lipopolysaccharides; Male; Middle Aged; Monocytes; Postmenopause; Sex Factors; Thromboplastin

BACKGROUND-Intravascular clotting has been implicated in the pathogenesis of cardiac allograft vasculopathy (CAV). We previously identified the expression of tissue factor (TF), the primary cellular initiator of blood coagulation, within the coronary intima, which was associated with neointimal thickening. In the present study, the effect of recombinant hirudin on CAV was assessed in Lewis to Fisher rat heterotopic cardiac allografts. METHODS AND RESULTS-Transplant recipients were randomized to a control group (n=10) and a hirudin-treated group (n=12; 2 mg. kg(-1). d(-1) SC). Histological evaluations of rejection, CAV, and TF staining were performed 120 days after transplantation. No significant differences were observed between the 2 groups with respect to the degree of rejection. Hirudin significantly (P<0.05) suppressed the development of CAV in the graft microvessels, but it was less effective in large coronary arteries. Graft intimal cells, isolated by laser-assisted cell picking, showed a marked upregulation of TF gene transcription, which was prevented by hirudin (P<0.01). As demonstrated by immunohistochemistry and quantitative analyses of TF mRNA levels by real-time polymerase chain reaction, hirudin treatment resulted in a significant reduction of TF protein and mRNA expression (P<0.001). CONCLUSIONS-Treatment with hirudin in this rat cardiac transplant model inhibited TF expression and decreased neointimal hyperplasia. These results suggest that TF inhibition by hirudin, in addition to its direct effect on thrombin, may attenuate the hypercoagulable state and prevent the development of CAV at least in restricted sites of the graft coronary vasculature.

Topics: Animals; Coronary Artery Disease; Coronary Vessels; Heart Transplantation; Hirudins; Male; Postoperative Period; Rats; Rats, Inbred F344; Rats, Inbred Lew; Thromboplastin; Transplantation, Homologous

Tissue factor (TF) initiates the extrinsic pathway of blood coagulation by acting as a cofactor for Factor VII. Inhibition of the Factor VIIa-TF complex is mediated by the tissue factor pathway inhibitor (TFPI), which is a serine protease inhibitor with three Kunitz-type domains. The localization of TF and TFPI protein has been examined immunohistochemically in various atherosclerotic lesions of coronary arteries from 22 autopsy cases and their messenger RNA expression has been confirmed by reverse transcription-polymerase chain reaction. Four types of atherosclerotic lesion (types I, II, III, and IV) were classified according to the method described by Stary et al. TF and TFPI were localized in endothelial cells, macrophages, macrophage-derived foam cells, and smooth muscle cells in the intimal lesions, medial smooth muscle cells, and endothelial cells of the microvessels in the adventitia. Immunohistochemical double staining revealed the co-localization of TF and TFPI in the endothelial cells and macrophages in four types of atherosclerotic lesions. In type III and IV lesions, the number of TF- and TFPI-positive cells was increased, accompanied by extracellular localization of TF and TFPI in the lipid core of atherosclerotic plaques. Fibrin deposition was found around TF- and TFPI-positive macrophages and in the lipid core of atherosclerotic plaques. TF and TFPI messenger RNA were detected more frequently in coronary arteries with type III and IV lesions than in those with type I and II lesions. The co-localization of TF and TFPI was demonstrated in various atherosclerotic lesions of coronary arteries and was shown to be intimately related to fibrin deposition in advanced atherosclerotic plaques. The co-localization of TF and TFPI may thus be closely associated with thrombogenicity in atherosclerotic lesions of coronary arteries.

Topics: Aged; Aged, 80 and over; Coronary Artery Disease; Coronary Vessels; Endothelium, Vascular; Female; Fibrin; Foam Cells; Humans; Immunohistochemistry; Lipoproteins; Macrophages; Male; Middle Aged; Muscle, Smooth, Vascular; Polymerase Chain Reaction; RNA, Messenger; Serine Proteinase Inhibitors; Thromboplastin

To investigate the changes of tissue factor (TF) and tissue factor pathway inhibitor(TFPI) activities in patients with hypertension or coronary atherosclerotic heart (CAH) disease.. TF activity was measured by two-stage assay, and TFPI activity was detected according to Sandset's method.. Plasma TF activity in both patients with hypertension and patients with CAH disease was higher than that of normal control(P < 0.05).. Hypercoagulative state may be involved in the pathogenetic processes of hypertension and CAH diseases. TF and TFPI activities have the likelihood to become the accessory diagnostic indexes for hypertension and CAH diseases.

Topics: Adult; Aged; Coronary Artery Disease; Female; Humans; Hypertension; Lipoproteins; Male; Middle Aged; Thromboplastin

Tissue factor (TF) has been implicated in several important biologic processes, including fibrin formation, atherogenesis, angiogenesis, and tumor cell migration. In that plasminogen activators have been implicated in the same processes, the potential for interactions between TF and the plasminogen activator system was examined. Plasminogen was found to bind directly to the extracellular domain of TF apoprotein (amino acids 1-219) as determined by optical biosensor interaction analysis. A fragment of plasminogen containing kringles 1 through 3 also bound to TF apoprotein, whereas isolated kringle 4 and miniplasminogen did not. Expression of TF on the surface of a stably transfected Chinese hamster ovary (CHO) cell line stimulated plasminogen binding to the cells by 70% more than to control cells. Plasminogen bound to a site on the TF apoprotein that appears to be distinct from the binding site for factors VII and VIIa as judged by a combination of biosensor and cell assays. TF enhanced two-chain urokinase (tcuPA) activation of Glu-plasminogen, but not of miniplasminogen, in a dose-dependent, saturable manner (half maximal stimulation at 59 pmol/L). TF apoprotein induced an effect similar to that of relipidated TF, but a relatively higher concentration of the apoprotein was required (half maximal stimulation at 3.8 nmol/L). The stimulatory effect of TF on plasminogen activation was confirmed when plasmin formation was examined directly on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In accord with this, TF inhibited fibrinolysis by approximately 74% at a concentration of 14 nmol/L and almost totally inhibited the binding of equimolar concentrations of plasminogen to human umbilical vein endothelial cells and human trophoblasts. Further, CHO cells expressing TF inhibited uPA-mediated fibrinolysis relative to a wild-type control. TF apoprotein and plasminogen were found to colocalize in atherosclerotic plaque. These data suggest that plasminogen localization and activation may be modulated at extravascular sites through a high-affinity interaction between kringles 1 through 3 of plasminogen and the extracellular domain of TF.

Topics: Animals; Apoproteins; Binding Sites; Binding, Competitive; Biosensing Techniques; Cells, Cultured; CHO Cells; Coronary Artery Disease; Cricetinae; Cricetulus; Endothelium, Vascular; Factor VII; Fibrinolysin; Fibrinolysis; Humans; Kinetics; Kringles; Phospholipids; Plasminogen; Plasminogen Activators; Protein Binding; Recombinant Fusion Proteins; Thromboplastin; Transfection; Urokinase-Type Plasminogen Activator

Coronary atherosclerotic-plaque thrombosis is a key event in the pathogenesis of unstable angina and myocardial infarction. Although plaque rupture or fissuring frequently occurs in atherosclerosis, only a small proportion of ruptured plaques develop thromboses.. Tissue-factor antigen and activity were measured in atherectomy samples from 50 consecutive patients with coronary artery disease (stable angina n = 19, unstable angina n = 24, and myocardial infarction n = 7).. Median tissue-factor antigen and activity concentrations were significantly higher in plaques from patients with unstable angina and myocardial infarction than in those from patients with stable angina (antigen: 66.1 pg/mg [interquartile range 43.8-82.5] vs 32.4 pg/mg [9.8-43.4], p = 0.0001; activity: 0.22 mU/mg [0.17-0.41] vs 0.13 mU/mg [0.05-0.16], p = 0.0004).. Tissue-factor, an initiator of the coagulation cascade, may account for the different thrombotic responses to the rupture of human coronary atherosclerotic plaques.

Topics: Angina Pectoris; Angina, Unstable; Antigens; Coronary Artery Disease; Humans; Myocardial Infarction; Thromboplastin

Recent observations suggest that thrombosis in vivo is initiated via the tissue factor (TF) pathway. The TF activity of human coronary atheroma has not been reported.. Directional coronary atherectomy (DCA) specimens from 63 lesions were analyzed with the use of a quantitative TF-specific activity assay. The median content of TF was 10 ng/g plaque (95% CI, 6 to 13 ng/g; range, 0 to 47 ng/g). After homogenization of the specimens, TF activity was detected in 28 of 31 lesions (90%). With a polyclonal anti-human TF antibody, the use of immunohistochemistry detected TF antigen in 43 of 50 lesions (86%); TF antigen was expressed in cellular and acellular areas of the plaque. Histologically defined thrombus was present in 19 of the 43 lesions with detectable TF antigen and in none of the 7 lesions without detectable TF antigen (19 of 43 versus 0 of 7; P < .02). TF antigen was undetectable with immunohistochemistry in 4 of 13 restenotic lesions (31%) and in 3 of 37 de novo lesions (8%) (P < .05).. TF contributes to the procoagulant activity of most atherosclerotic lesions treated with DCA. The association of immunohistochemically detectable TF with plaque thrombus suggests that TF plays a role in coronary thrombosis. Diminished TF expression in restenotic lesions may in part account for the lower complication rate that has been associated with DCA of restenotic versus de novo lesions. Inhibition of TF may represent a therapeutic goal for the prevention of thrombotic complications associated with percutaneous coronary interventions.

Topics: Antigens; Arteriosclerosis; Biological Availability; Coronary Artery Disease; Factor Xa; Humans; Immunohistochemistry; Staining and Labeling; Thromboplastin; Time Factors

Accelerated coronary atherosclerosis in cardiac allografts is the major limiting factor for long-term survival after heart transplantation. There is growing evidence that activation of the coagulation mechanism is involved in the development of transplant atherosclerosis. Tissue factor (TF) expression by cells of the monocyte/macrophage system may represent an important mechanism underlying the fibrin deposition in the affected vessels. In the present study, we investigated the effect of cyclosporine A (CsA) on the lipopolysaccharide (LPS)-induced procoagulant activity (PCA) in human monocytes/macrophages. CsA exerted a dose-dependent inhibitory effect on LPS-induced monocyte/macrophage PCA, which was identified as TF activity based on functional and immunologic characterization. As shown by reverse transcriptase-polymerase chain reaction, CsA reduced the transcription of the TF gene in LPS-stimulated monocytes/macrophages. Electrophoretic mobility shift assay showed that CsA inhibited the LPS-induced activation of the nuclear factor kappa B (NF-kappa B). As shown by Western blot analysis, CsA treatment decreased the nuclear translocation of NF-kappa B, thereby suggesting the mechanism for the inhibitory effect of CsA on TF induction. Hence, a nonimmunologic effect of CsA may contribute to its successful use in transplant medicine.

Topics: Biological Transport; Blood Coagulation Factors; Cell Nucleus; Cells, Cultured; Coronary Artery Disease; Cyclosporine; Depression, Chemical; Gene Expression Regulation; Heart Transplantation; Humans; Lipopolysaccharides; Macrophages; Monocytes; NF-kappa B; Postoperative Complications; Protein Binding; Thromboplastin; Transcription, Genetic

Macrophage expression of tissue factor may be responsible for coronary thrombogenicity in patients with plaque rupture. In patients without plaque rupture, smooth muscle cells may be the thrombogenic substrate. This study was designed to identify the cellular correlations of tissue factor in patients with unstable angina.. Tissue from 50 coronary specimens (1560 pieces) from patients with unstable angina and 15 specimens from patients with stable angina were analyzed. Total and segmental areas (in square millimeters) were identified with trichrome staining. Macrophages, smooth muscle cells, and tissue factor were identified by immunostaining. Tissue factor content was larger in unstable angina (42 +/- 3%) than in stable angina (18 +/- 4%) (P = .0001). Macrophage content was also larger in unstable angina (16 +/- 2%) than in stable angina (5 +/- 2%) (P = .002). The percentage of tissue factor located in cellular areas was larger in coronary samples from patients with unstable angina (67 +/- 8%) than in samples from patients with stable angina (40 +/- 5%) (P = .00007). Multiple linear stepwise regression analysis showed that coronary tissue factor content correlated significantly (r = .83, P < .0001) with macrophage and smooth muscle cell areas only in tissue from patients with unstable angina, with a strong relationship between tissue factor content and macrophages in the atheromatous gruel (r = .98, P < .0001).. Tissue factor content is increased in unstable angina and correlates with areas of macrophages and smooth muscle cells, suggesting a cell-mediated thrombogenicity in patients with acute coronary syndromes.

Topics: Adult; Aged; Angina Pectoris; Angina, Unstable; Atherectomy, Coronary; Coronary Artery Disease; Coronary Vessels; Female; Humans; Immunohistochemistry; Lipids; Macrophages; Male; Middle Aged; Muscle, Smooth, Vascular; Regression Analysis; Thromboplastin