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The hypercoagulable state of malignancy: pathogenesis and current debate.

A hypercoagulable or prothrombotic state of malignancy occurs due to the ability of tumor cells to activate the coagulation system. It has been estimated that hypercoagulation accounts for a significant percentage of mortality and morbidity in cancer patients. Prothrombotic factors in cancer include the ability of tumor cells to produce and secrete procoagulant/fibrinolytic substances and inflammatory cytokines, and the physical interaction between tumor cell and blood (monocytes, platelets, neutrophils) or vascular cells. Other mechanisms of thrombus promotion in malignancy include nonspecific factors such as the generation of acute phase reactants and necrosis (i.e., inflammation), abnormal protein metabolism (i.e., paraproteinemia), and hemodynamic compromise (i.e., stasis). In addition, anticancer therapy (i.e., surgery/chemotherapy/hormone therapy) may significantly increase the risk of thromboembolic events by similar mechanisms, e.g., procoagulant release, endothelial damage, or stimulation of tissue factor production by host cells. However, not all of the mechanisms for the production of a hypercoagulable state of cancer are entirely understood. In this review, we attempt to describe what is currently accepted about the pathophysiology of the hypercoagulable state of cancer. We also discuss whether or not to screen patients with idiopathic deep venous thrombosis for an underlying malignancy, and whether this would be beneficial to patients. It is hoped that a better understanding of these mechanisms will ultimately lead to the development of more targeted treatment to prevent thromboembolic complications in cancer patients. It is also hoped that antithrombotic strategies may also have a positive effect on the process of tumor growth and dissemination.

Antineoplastic Agents↗

Hypercoagulable states and stroke: a selective review.

Blood disorders have been implicated in approximately 5% to 10% of ischemic stroke, with an increased frequency in younger patients. Most disorders are associated with an increased thrombotic tendency and, therefore, an increased risk of ischemic stroke. Less commonly, a bleeding diathesis may predispose a patient to intracranial hemorrhage. While many conditions predisposing to thrombosis have been associated with stroke, there are relatively few prospective, epidemiological studies addressing hypercoagulable states and arterial stroke compared with the number of studies on the genetic thrombophilias, which are predominantly associated with venous thrombosis. When ordering tests of coagulation in stroke patients, one should keep in mind whether the results will influence therapy and/or patient outcome. It is generally not advocated to screen all stroke patients for a "hypercoagulable workup". Typically, patients to be screened for coagulation defects will have a prior history of one or more unexplained thromboembolic events. The yield for diagnosing a hypercoagulable state is typically greatest for young stroke patients or those with a family history of thrombosis and who have no other explanations for their stroke (cryptogenic stroke). The yield in typically low in unselected ischemic stroke patients and older patients. Treatment of a first stroke with a documented hypercoagulable state is typically long-term or indefinite duration warfarin, although there is a paucity of clinical trial data supporting this clinical approach.

Humans↗

A case of reversible posterior leukoencephalopathy syndrome caused by transient hypercoagulable state induced by infection.

We report a normotensive case of reversible posterior leukoencephalopathy syndrome caused by transient hypercoagulable state. Hypertension is the main risk factor for reversible posterior leukoencephalopathy syndrome, which is believed to occur as a result of high blood pressure-related dysfunction of cerebrovascular endothelial cells, because it commonly appears in hypertensive emergency. However, in this completely normotensive case, the typical clinical findings of reversible posterior leukoencephalopathy syndrome were triggered by transient hypercoagulable state without any blood pressure variation. The case was successfully treated with anticoagulation therapy using heparin. Thus, this case indicates that reversible posterior leukoencephalopathy syndrome is induced by cerebrovascular endothelial dysfunction, which is induced not only by high blood pressure but also hemostatic dysfunction.

Aged↗

An evaluation of 200 consecutive patients with spontaneous or recurrent thrombosis for primary hypercoagulable states.

Two hundred consecutive patients who were referred for evaluation of spontaneous or recurrent thrombosis were investigated for possible hypercoagulable states to determine the relative frequencies of these conditions in the Australian population and to identify features that would indicate which patients should be investigated with the expensive battery of tests for hypercoagulable states. Thirty-two percent were found to have prolongation of the postvenous occlusion euglobulin clot lysis time (PVO-ELT), 32% were found to have elevated levels of plasminogen activator inhibitor-1 (PAI) and 66% were found to have reduced release of tissue plasminogen activator (tPA). Antiphospholipid antibodies were found in 12%. Hereditary antithrombin III deficiency was found in 2%. Hereditary deficiency of the naturally-occurring anti-coagulant factors protein C and protein S was found in 2%. Age, sex, site of thrombosis (venous or arterial), or presence of a family history was not helpful in predicting a group more likely to have abnormal investigation results. Reduced fibrinolytic activity and the presence of antiphospholipid antibodies are the most common findings in patients with thromboembolic disease. Further prospective studies are required to assess the natural history and appropriate management of patients with these abnormalities.

Adolescent↗

Clinical and laboratory evaluation of the hypercoagulable states.

In summary, every patient presenting with a new (or recurrent) thromboembolic event should be carefully assessed for potential predisposing factors. This starts with a thorough patient history and complete physical examination. If indicated, the clinical assessment is then used to guide the clinical laboratory evaluation for a potential hypercoagulable state. Identification of a specific hypercoagulable state, primary or secondary, is extremely important in the prognosis and therapeutic management of the individual patient.

Blood Coagulation Disorders↗

Effect of degree of blood pressure on the hypercoagulable state in chronic atrial fibrillation.

To investigate the hypothesis that higher levels of blood pressure would further promote the hypercoagulable state in atrial fibrillation (AF) by increasing the degree of hemostatic abnormalities, we studied 82 consecutive patients with chronic nonvalvular AF who were not taking antithrombotic therapy. Patients with AF had higher levels of plasma fibrin D-dimer, von Willebrand factor, and fibrinogen than controls in sinus rhythm, and no differences between tertiles of either systolic, diastolic, or mean blood pressure were found, suggesting other mechanisms may be contributing to the hypercoagulable state in AF.

Aged↗

The hypercoagulable state in sleep apnea is related to comorbid hypertension.

OBJECTIVE: Obstructive sleep apnea (OSA) is associated with increased prevalence of atherosclerotic disease. A hypercoagulable state thought to underly atherosclerosis has been described in both OSA and systemic hypertension. We wondered about the respective contribution of apnea and hypertension to a hypercoagulable state. DESIGN: Eighty-seven subjects with symptoms suggestive of OSA, mean age 47 years (range 32-64 years), underwent polysomnography and blood pressure (BP) screening. OSA was diagnosed when respiratory disturbance index (RDI) > or = 15. Subjects having systolic BP (SBP) > 140 mmHg and/or diastolic BP (DBP) > 90 mmHg were classified as having hypertension. Three hypercoagulability markers were measured: thrombin/antithrombin III complex (TAT), fibrin D-dimer (DD), and von Willebrand factor antigen (vWF:ag). RESULTS: Analysis of variance and multiple linear regression were performed on the following four subject groups: (1) normotensive non-apneics (n = 19), (2) normotensive apneics (n = 38), (3) hypertensive non-apneics (n = 11), and (4) hypertensive apneics (n = 19). OSA (groups 2 and 4) had no significant main effect on hemostasis. Hypertensives (groups 3 and 4) had higher plasma levels of TAT (median/inter-quartile range, 148/59-188 versus 77/53-108 pmol/l; P = 0.009) and of DD (376/265-721 versus 303/190-490 ng/ml; P = 0.040) than normotensives (groups 1 and 2). Across all subjects, SBP was the only significant predictor of TAT (P = 0.001) and of DD (P = 0.004), whereas DBP was the only significant predictor of vWF:ag (P = 0.029). These findings persisted even after controlling for gender, age, body mass index, RDI, mean SaO2, and hematocrit. CONCLUSION: Hypercoagulability in OSA is mediated by comorbid hypertension and might account for high cardiovascular morbidity in OSA in general.

Adult↗

Management and prevention of thromboembolic events in patients with cancer-related hypercoagulable states: a risky business.

OBJECTIVE: To determine the optimal strategy for managing and preventing thromboembolic events in malignancy-associated hypercoagulable states. DESIGN: A Markov-based decision and cost-effectiveness analysis was performed. The authors explicitly considered consequences of embolic and bleeding events, filter complications, and cancer-related excess mortality. Data were drawn from the current literature. The main outcome measure for each strategy was the quality-adjusted life expectancy and the total average variable costs. SUBJECTS: Patients with advanced malignancies prone to develop thromboembolic events, patients with acute proximal deep venous thrombosis (DVT), and patients who have survived a first episode of pulmonary embolism (PE). INTERVENTIONS: The authors considered three different interventions: 1) OBSERVATION, in which neither anticoagulant therapy nor filter placement is pursued, 2) ANTICOAGULATION, in which long-term anticoagulant therapy is started immediately, and 3) VENA CAVAL FILTER. MAIN RESULTS: Vena caval filter was the preferred strategy for every malignancy studied, yielding an 11% gain in quality-adjusted life expectancy, compared with observation, for patients with acute DVT, and an 18% gain for patients having survived a PE. Anticoagulant therapy yielded gains of 9% and 16%, respectively. Compared with anticoagulant therapy, filter was less costly due to the avoidance of additional expenses incurred by bleeding events. Prophylactic therapy was the least effective of the three strategies examined. CONCLUSIONS: Vena caval filter placement and long-term anticoagulation therapy yield similar outcomes in the setting of cancer-related hypercoagulable states. However, filter insertion is less expensive than anticoagulation. Given the short life expectancy and morbidity of patients with end-stage malignancy, patient preferences for health states must be considered in the decision-making process. If active treatment is pursued, vena caval filter should be used as a primary therapy. Prophylactic therapy is not warranted in any circumstance.

Aged↗

Hypercoagulable state in a hypobaric, hypoxic environment causes non-bacterial thrombotic endocarditis in rats.

High-altitude hypoxia causes polycythaemia and a hypercoagulable state in humans and animals. This study examines the effects of a hypobaric, hypoxic environment (HHE) on the blood coagulation system in rats. A total of 170 male Wistar rats were housed in a chamber at the equivalent of 5500 m in altitude for 1-12 weeks. After 2 weeks of exposure to HHE, platelet counts decreased significantly; after 4 weeks, the prothrombin and activated partial thromboplastin times were significantly prolonged, compared with those of control rats. In addition, individual coagulation factors (VII, IX, X, XI, and XII) were significantly decreased at 8 weeks (P < 0.05). Levels of anti-thrombin III and alpha 2-plasmin inhibitor also decreased (between 4 and 8 weeks). After 4-12 weeks of exposure to HHE, 30 of 56 rats (54 per cent) developed (i) non-bacterial thrombotic endocarditis (NBTE) or (ii) infarction of the myocardium or kidney, or both (i) and (ii). The incidence of NBTE increased from 33 per cent (5/15 rats) at 4 weeks to 100 per cent (7/7 rats) at 12 weeks. Electron microscopy showed detached endothelial cells in the mitral valves at 1 week; platelets adhered to the subendocardial matrix and platelet aggregation with thrombus formation was seen at 2 weeks of exposure. The results suggest that exposure to HHE induces a hypercoagulable state and causes an NBTE in rats that may result in consumption coagulopathy.

Altitude Sickness↗

Hypercoagulable states as an evolving risk for spontaneous venous and arterial thrombosis.

This study of 49 patients with spontaneous venous and arterial thrombosis identified 27 with hypercoagulable states: 13 had only venous thrombosis (VT), six had episodes of VT followed by arterial thrombosis (AT) and eight had AT only. All 27 patients were less than 42 years of age; 22 had specific natural anticoagulant or fibrinolytic deficiencies: antithrombin III (nine patients), protein C (eight patients), protein S (three patients), heparin cofactor II (two patients), tissue plasminogen activator release (one patient) and mixed antithrombin III and protein S (one patient). The remaining five patients had recurrent thrombotic events associated with resistance to heparin anticoagulation, but no established laboratory diagnosis. Clotting complications included recurrent VT, pulmonary embolism, multiple failed arterial procedures and lower extremity amputation. The remaining 22 patients (mean age of 53 years, range of 46 to 63 years), 12 with VT and ten with AT, did not have laboratory evidence of hypercoagulability and none had recurrent vascular occlusions. All these patients were successfully treated by conventional therapy without any additional thrombotic events during the follow-up period. Young adults with spontaneous thrombotic events should be screened for possible hypercoagulable states. Additionally, these young patients need further evaluation and treatment of cardiovascular risk factors. Those with premature atherosclerosis have an especially poor prognosis despite surgical intervention and anticoagulant therapy.

Adult↗

The effects of gemfibrozil upon the hypercoagulable state in dyslipidaemic patients with chronic renal failure.

BACKGROUND: The dyslipidaemia of chronic renal disease could contribute to a hypercoagulable state by activation of blood coagulation and/or impairment of fibrinolysis, thereby increasing cardiovascular disease (CVD) risk. METHODS: We measured the coagulation activation marker prothrombin fragment F1 + 2 (F1 + 2), fibrinogen, plasminogen activator inhibitor-1 activity (PAI1), interleukin-6 (IL6), insulin, lipids and lipoprotein(a) (Lp(a)), in 12 patients with chronic renal disease before and after gemfibrozil. RESULTS: Gemfibrozil significantly reduced triglycerides by 44% and increased HDL-cholesterol by 31% without significant change in LDL cholesterol. Before treatment, patients had increased F1 + 2, fibrinogen and IL6, but similar PAI1 compared with the controls, consistent with a hypercoagulable and persistent inflammatory state. Following treatment, F1 + 2 decreased to within the normal range and this reduction correlated with the decrease in triglycerides and inversely with the increase in HDL-cholesterol. A non-significant decrease in fibrinogen was inversely correlated with a significant increase in albumin. However, Lp(a) and PAI1 activity significantly increased whilst insulin and IL6 were unchanged. CONCLUSIONS: Gemfibrozil improved the uraemic dyslipidaemia and hypercoagulable state by reduction in activation of blood coagulation, indirectly suggesting a reduction in lipid-dependent extrinsic pathway activity which should contribute to reduced risk of thrombosis and CVD. Reduced fibrinogen and increased albumin are consistent with a reduction in the acute phase response. Increased PAI1 and Lp(a) could impair fibrinolysis and potentially increase CVD risk, although the mechanism for these effects is uncertain but does not appear related to cytokine or insulin mediated mechanisms and requires further study. Large prospective studies are required to determine if gemfibrozil can reduce CVD events in uraemia.

Adult↗

Prothrombin gene mutation G20210A, homocysteine, antiphospholipid antibodies and other hypercoagulable states in ocular thrombosis.

The purpose of the present study was to determine whether using an extended panel of laboratory tests increases the detection of a hypercoagulable state in patients with ocular thromboses. Twenty consecutive patients with ocular thromboses (vein, artery, or choriocapillaris occlusions) underwent testing for activated protein C resistance/factor V Leiden, prothrombin G20210A, lupus anticoagulant, anticardiolipin antibodies, hyperhomocysteinemia, and deficiencies of protein C, protein S, and antithrombin. For each patient, we selected two age-matched and gender-matched individuals without ocular thromboses as controls. Sixteen of the 20 patients (80%) had one or more laboratory tests that supported a hypercoagulable condition. Prothrombin G20210A (P < 0.02) and hyperhomocysteinemia (P < 0.0006) were significantly more frequent in ocular thrombosis patients compared with controls. The most common condition was antiphospholipid antibody syndrome, present in 40% of patients (confirmed by repeat testing at least 6 weeks later), but this did not reach statistical significance compared with the controls. No patients with ocular thromboses had hereditary abnormalities of protein S, protein C, or antithrombin. In conclusion, an extended panel of laboratory tests improved the detection of a hypercoagulable state in ocular thromboses. Testing for homocysteine, antiphospholipid antibodies, and the prothrombin G20210A mutation should be considered in patients with ocular thromboses.

Activated Protein C Resistance↗

Renal transplantation in patients with hypercoagulable states.

Early vascular thrombotic complications in renal transplantation frequently result in loss of the allograft with an increased long-term incidence of renal dysfunction from venous and arterial thrombosis. Hypercoagulable states are recognized risk factors of allograft thrombosis but are seldom discussed in the literature. This is the first report of preemptive heparin anticoagulation of two hypercoagulable patients undergoing renal transplantation, resulting in long term allograft success with warfarin anticoagulation. We recommend that any hemodialysis patient who has had recurrent dialysis graft thrombosis with a few months' time be evaluated for possible hypercoagulable state. Our experience suggests that appropriate management of such patients includes warfarin therapy. Renal transplantation can be successful in such patients provided heparin is given before, during, and after surgery followed by reinstitution of warfarin prior to discharge from the hospital.

Anticoagulants↗

Evaluation of the in vitro detection of the hypercoagulable state using the thrombin generation test and plasma clot impedance test.

This study reports the correlation of the thrombin generation test and the plasma clot impedance test with clinical evidence of hypercoagulability. Thrombin generation is increased and the rate of change of plasma from a liquid to a gel (clot impedance) is increased in situations where the risk of thrombosis is increased. These situations include increasing clinical signs and/or symptoms of thromboembolism, positive lung scans, postoperative total hip replacement, patients over 40 years old, low serum antithrombin III, thrombocytosis, transient cerebral ischemia, and positive isotope venogram for thrombosis. The two tests failed to indicate a significant effect of antiplatelet drugs on the hypercoagulable state. This study shows that the thrombin generation and plasma clot impedance tests are practical, rapid and useful tests for the detection and monitoring of the hypercoagulable state.

Adult↗

Hypercoagulable states and strokes.

Several hematologic disorders and hemostatic defects increase risk of ischemic stroke. A common feature of these disorders is the creation of a prothrombotic state, now commonly referred to as "hypercoagulable state." Hematologic diseases such as essential thrombocythemia, polycythemia vera, and thrombotic thrombocytopenic purpura clearly cause stroke. Effective treatment is now available for these disorders. Association of hemostatic defects with stroke risk is still at the investigational stage. Although a number of factors such as soluble thrombomodulin, fibrinogen, factor VIII, von Willebrand factor, and plasminogen activator inhibitor-1 are associated with stroke risk, their predictive values remain unknown. Furthermore, causal relationship has not been established.

Blood Coagulation↗

The Jeremiah Metzger Lecture. Hypercoagulable states: challenges and opportunities.

Thromboregulatory physiology is essentially a function of the blood vessel wall. Constitutive endothelial cell activities maintain blood fluidity by down regulating the initiation as well as, the propagation of blood coagulation. The major systems involved include: the Protein C, TFPI, plasmin generating and antithrombin pathways, all of which are focused on the cell membrane. Altered regulation of these endothelial functions forms the basis of the pathophysiologic events associated with the inherited primary hypercoagulable states. Secondary hypercoagulable syndromes occurring in various clinical states with conversion to a vascular thrombogenic phenotype reflect non constitutive activated endothelial cell functions with concomitant down regulation of the constitutive anticoagulant surface activity. So called idiopathic clinical thrombosis in most circumstances represents multi hit events in which specific genetic abnormalities or polymorphisms together with specific acquired alterations in geographically distinct endothelial cell beds culminate in a recognizable coagulation phenotype.

Animals↗

Plasma D-dimer levels and their relationship to serum fibrinogen/fibrin degradation products in hypercoagulable states.

Plasma D-dimer was measured and compared with serum fibrinogen/fibrin degradation product levels (FDPs) in patients with disseminated intravascular coagulation (DIC) and other conditions associated with a hypercoagulable state. D-dimer (N less than 200 ng/ml) was elevated in all 43 patients with DIC, in 48 of 59 patients with liver disease, in 22 of 27 patients with acute leukaemia at presentation, in 17 of 23 patients with malignant disease, in 29 of 39 women in the third trimester of a complicated pregnancy, in 17 of 18 patients with deep venous thrombosis and in only four of 27 patients with acute myocardial infarction. There was a significant correlation between plasma D-dimer and serum FDP levels (P less than 0.01) as follows; DIC: r = 0.58, liver disease: r = 0.57, acute leukaemia: r = 0.84, malignancy: r = 0.87. The frequent elevation of D-dimer observed in liver disease, acute leukaemia, malignancy and complicated pregnancy indicates that a hypercoagulable state is a common occurrence in these conditions although in liver disease elevated levels resulting from a failure of normal clearance mechanisms cannot be excluded. The close relationship between D-dimer and FDP levels suggests that serum FDPs predominantly arise from the interaction of plasmin with crosslinked fibrin rather than with fibrinogen in the conditions in which these were compared.

Blood Coagulation Disorders↗