vitamin-k-semiquinone-radical and Thrombophilia

Topics: Administration, Oral; Anticoagulants; Antithrombins; Atrial Fibrillation; Brain Ischemia; COVID-19; Drug Monitoring; Drug Substitution; Factor Xa Inhibitors; Humans; Inpatients; Prognosis; SARS-CoV-2; Thrombophilia; Venous Thromboembolism; Vitamin K

Venous thromboembolism (VTE) in children is a rare occurrence, although in recent decades we have seen an increase due to several factors, such as the rise in survival of subjects with chronic conditions, the use of catheters, and the increased sensitivity of diagnostic tools. Besides inherited thrombophilia, acquired conditions such as cardiovascular diseases, infections, chronic disorders, obesity and malignancy are also common risk factors for paediatric VTE. The treatment of paediatric VTE consists of the use of heparins and/or vitamin K antagonists to prevent dissemination, embolization, and secondary VTE. Randomized clinical trials of direct oral anticoagulants in paediatric VTE are ongoing, with the aim to improve the compliance and the care of patients. We reviewed the physiological and pathological mechanisms underlying paediatric thrombosis and updated the current diagnosis and treatment options.

Topics: Anticoagulants; Child; Heparin; Humans; Neoplasms; Randomized Controlled Trials as Topic; Risk Factors; Thrombophilia; Venous Thromboembolism; Vitamin K

Antiphospholipid syndrome (APS), heparin-induced thrombocytopenia, and paroxysmal nocturnal hemoglobinuria are 3 acquired thrombophilias that carry a high risk of venous and arterial thromboembolism. Management of these conditions has largely included anticoagulation with a vitamin K antagonist after an initial period of a parenteral anticoagulant, for as long as the thrombotic risk is still present. The available evidence for the use of direct oral anticoagulants (DOACs) is limited and primarily consists of case series and cohort studies, which are summarized in this chapter. Randomized trials evaluating DOACs in patients with APS are reviewed. Further research is needed prior to widely adopting DOACs for use in these high-risk acquired thrombophilias; however, there may be selected low-risk subgroups where DOAC use is possible after careful consideration and patient discussion.

Topics: Administration, Oral; Anticoagulants; Antiphospholipid Syndrome; Disease Management; Hemoglobinuria, Paroxysmal; Heparin; Humans; Thrombocytopenia; Thrombophilia; Thrombosis; Vitamin K

The present article provides an update on anticoagulant treatment in patients with atrial fibrillation in distinct clinical scenarios requiring particular considerations, such as ischaemic heart disease, electrical cardioversion, pulmonary vein ablation, the presence of valvular disease with or without prosthetic valves, and renal insufficiency, as well as old age and frailty. In patients with non-valvular atrial fibrillation, the presence of renal insufficiency increases both thrombotic and haemorrhagic risk. In mild and moderate stages, direct-acting anticoagulants confer a greater benefit than warfarin, although they usually require dose adjustment. In renal failure/dialysis, there is no solid evidence that warfarin is beneficial and the use of direct-acting anticoagulants is not recommended. Because of its pathophysiology, oral anticoagulation could have a beneficial effect in patients with heart disease. However, vitamin K antagonists have not shown a satisfactory risk-benefit ratio. In contrast, direct-acting anticoagulants, at reduced doses, could have a beneficial effect in this scenario in association with antiplatelet agents. The use of direct-acting anticoagulants prior to electrical cardioversion in patients with non-valvular atrial fibrillation seems to be associated with a risk of cardioembolic events that is at least comparable to that of vitamin K antagonists. Their use avoids delay in the application of electrical cardioversion in patients without adequate INR levels. In the context of their use before and after atrial fibrillation ablation, dabiga-tran and rivaroxaban have demonstrated at least non-inferiority with vitamin K antagonists in terms of safety. In patients with any type or grade of valvular disease and atrial fibrillation, the indication of antithrombo-tic treatment must be evaluated in the same way as in patients with atrial fibrillation and no valvular di-sease. Whenever anticoagulation is required, direct-acting anticoagulants are the treatment of choice in nearly all situations, except in patients with mechanical valves or who have significant rheumatic mitral disease, who should be treated with vitamin K antagonists. The choice of appropriate antithrombotic stra-tegy in frail elderly patients is complex and involves multiple factors beyond assessment of embolic and haemorrhagic risk. Comprehensive geriatric assessment is essential for an individualised final decision. Moreover, any such decision should be consensus-based

Topics: Acute Coronary Syndrome; Administration, Oral; Anticoagulants; Atrial Fibrillation; Clinical Trials as Topic; Electric Countershock; Fibrinolytic Agents; Heart Valve Diseases; Hemorrhage; Humans; International Normalized Ratio; Meta-Analysis as Topic; Multicenter Studies as Topic; Myocardial Ischemia; Renal Insufficiency; Risk Assessment; Secondary Prevention; Thromboembolism; Thrombophilia; Vitamin K; Warfarin

Antiphospholipid syndrome (APS), heparin-induced thrombocytopenia, and paroxysmal nocturnal hemoglobinuria are 3 acquired thrombophilias that carry a high risk of venous and arterial thromboembolism. Management of these conditions has largely included anticoagulation with a vitamin K antagonist after an initial period of a parenteral anticoagulant, for as long as the thrombotic risk is still present. The available evidence for the use of direct oral anticoagulants (DOACs) is limited and primarily consists of case series and cohort studies, which are summarized in this chapter. Randomized trials evaluating DOACs in patients with APS are reviewed. Further research is needed prior to widely adopting DOACs for use in these high-risk acquired thrombophilias; however, there may be selected low-risk subgroups where DOAC use is possible after careful consideration and patient discussion.

Topics: Administration, Oral; Anticoagulants; Antiphospholipid Syndrome; Hemoglobinuria, Paroxysmal; Heparin; Humans; Patient Education as Topic; Risk Factors; Thrombocytopenia; Thrombophilia; Vitamin K

As non-valvular atrial fibrillation (AF) brings a risk of stroke, oral anticoagulants (OAC) are recommended. In 'real world' clinical practice, many patients (who may be, or perceived to be, intolerant of OACs) are either untreated or are treated with anti-platelet agents. We hypothesised that edoxaban has a better net clinical benefit (NCB, balancing the reduction in stroke risk vs increased risk of haemorrhage) than no treatment or anti-platelet agents. We performed a network meta-analysis of published data from 24 studies of 203,394 AF patients to indirectly compare edoxaban with aspirin alone, aspirin plus clopidogrel, and placebo. Edoxaban 30 mg once daily significantly reduced the risk of all stroke, ischaemic stroke and mortality compared to placebo and aspirin. Compared to aspirin plus clopidogrel, there was a lower risk of intra-cranial haemorrhage (ICH). Edoxaban 60 mg once-daily had a reduced risk of any stroke and systemic embolism compared to placebo, aspirin, and aspirin plus clopidogrel. Mortality rates for both edoxaban doses were estimated to be lower compared to any anti-platelet, and significantly lower compared to placebo. With overall reduced risk of ischemic stroke and ICH, both edoxaban doses bring a NCB of mean (SD) 1.68 (0.15) saved events per 100 patients per year compared to anti-platelet drugs in a clinical trial population. The NCB was demonstrated to be lower, at 0.77 (0.12) events saved (p< 0.01) when modeled to data from a 'real world' cohort of AF patients. In conclusion, edoxaban is likely to provide even better protection from stroke and ICH than placebo, aspirin alone, or aspirin plus clopidogrel in both clinical trial populations and unselected community populations. Both edoxaban doses would also bring a positive NCB compared to anti-platelet drugs or placebo/non-treatment based on 'real world' data.

Topics: Anticoagulants; Aspirin; Atrial Fibrillation; Brain Ischemia; Cerebral Hemorrhage; Clopidogrel; Drug Synergism; Drug Therapy, Combination; Embolism; Factor Xa Inhibitors; Humans; Mortality; Numbers Needed To Treat; Observational Studies as Topic; Platelet Aggregation Inhibitors; Pyridines; Randomized Controlled Trials as Topic; Risk; Risk Assessment; Stroke; Thiazoles; Thrombophilia; Ticlopidine; Vitamin K

Direct oral anticoagulants (DOACs) are widely used as an alternative for warfarin. However, the impact of DOACs on mortality outcomes compared with warfarin remains unclear.. To estimate the mortality outcomes in patients treated with DOACs vs. warfarin (or another vitamin K antagonist).. MEDLINE, EMBASE and CENTRAL databases (inception to September 2014), conference abstracts and www.clinicaltrials.gov, were searched, without language restriction. Studies were selected if there were phase III, randomized trials comparing DOACs with warfarin in patients with non-valvular atrial fibrillation or venous thromboembolism.. Thirteen randomized controlled trials involving 102 707 adult patients were included in the analysis. The case-fatality rate of major bleeding was 7.57% (95% CI, 6.53-8.68; I(2) = 0%) in patients taking DOACs and 11.04% (95% CI, 9.16-13.07; I(2) = 33.3%) in patients taking warfarin. The rate of fatal bleeding in adult patients receiving DOACs was 0.16 per 100 patient-years (95% CI, 0.12-0.20; I(2) = 36.5%). When compared with warfarin, DOACs were associated with significant reductions in fatal bleeding (RR, 0.53; 95% CI, 0.43-0.64; I(2) = 0%), cardiovascular mortality (RR, 0.88; 95% CI, 0.82-0.94; I(2) = 0%) and all-cause mortality (RR, 0.91; 95% CI, 0.87-0.96; I(2) = 0%).. The use of DOACs compared with warfarin is associated with a lower rate of fatal bleeding, case-fatality rate of major bleeding, cardiovascular mortality and all-cause mortality.

Topics: Adult; Anticoagulants; Antithrombins; Atrial Fibrillation; Cardiovascular Diseases; Factor Xa Inhibitors; Hemorrhage; Humans; Mortality; Risk; Thromboembolism; Thrombophilia; Treatment Outcome; Vitamin K; Warfarin

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Benzimidazoles; Dabigatran; Elective Surgical Procedures; Emergencies; Factor Xa Inhibitors; Hemorrhage; Humans; Kidney Diseases; Morpholines; Orthopedic Procedures; Postoperative Complications; Premedication; Pyrazoles; Pyridines; Pyridones; Randomized Controlled Trials as Topic; Risk; Rivaroxaban; Thiophenes; Thrombophilia; Vitamin K

Anticoagulants are effective at preventing and treating thrombosis, but can cause bleeding. For decades, vitamin K antagonists (VKAs) have been the only available oral anticoagulants. The development of non-VKA oral anticoagulants (NOACs), which inhibit either factor Xa or thrombin stoichiometrically, has provided alternatives to VKAs for several indications. The results of recent large-scale randomised controlled trials comparing NOACs with VKAs for the prevention of stroke in patients with non-valvular atrial fibrillation (AF) have produced some unexpected results. As a group, NOACs showed similar efficacy as warfarin, but a reduced risk of major bleeding. The reduction in bleeding with NOACs was greatest with intracranial hemorrhage. In contrast, the relative risk of gastro-intestinal bleeding was increased with some NOACs. In this review, we explore the potential mechanisms as well as the implications of these organ-specific bleeding patterns.

Topics: Anticoagulants; Atrial Fibrillation; Blood Coagulation Factors; Endothelium, Vascular; Factor Xa Inhibitors; Gastrointestinal Hemorrhage; Hemorrhage; Humans; International Normalized Ratio; Intestinal Absorption; Intracranial Hemorrhages; Organ Specificity; Randomized Controlled Trials as Topic; Stroke; Thrombophilia; Thromboplastin; Vitamin K; Warfarin

Vitamin K antagonists have been shown to be effective in the primary and secondary prevention of systemic and cerebral emboli in patients with cardiac causes of embolism, especially atrial fibrillation. The reduced risk of stroke is greater in secondary prevention, although this reduction is accompanied by an inherent risk of hemorrhagic complications, among which cerebral hemorrhage is especially serious. The therapeutic window of these agents is limited and the best benefit/risk profile is obtained with an INR of between 2 and 3. The anticoagulant effect obtained shows marked variability, requiring frequent clinical and laboratory monitoring of the treatment. The introduction of oral anticoagulants that would aid the administration of these agents with equal or greater efficacy and lower risk is required.

Topics: Anticoagulants; Atrial Fibrillation; Blood Coagulation; Drug Monitoring; Fibrinolytic Agents; Heart Diseases; Humans; International Normalized Ratio; Intracranial Embolism; Primary Prevention; Risk; Secondary Prevention; Stroke; Thrombophilia; Vitamin K

Stroke and atrial fibrillation (AF) constitute a true vascular epidemic with catastrophic consequences. The most common and devastating complication of AF is cardioembolic stroke but this catastrophic event can be predicted and prevented. Accurate etiologic diagnosis of stroke is essential for effective prevention. The percentage of cryptogenic ischemic strokes is too high and detection of AF and other causes of cardioembolic events should be improved. Cardioembolic cerebral ischemia can be prevented. However, because of physician inertia, lack of patient adherence and the problems of vitamin K antagonists, many patients are at risk of cerebral ischemia. Recently, major advances with drugs such as dronedarone, dabigatran and FXa inhibitors have opened the way to improving stroke prevention, as reflected in therapeutic guidelines, and neurologists should be familiar with these drugs. There is reason to hope that much suffering can be avoided.

Topics: Anticoagulants; Atrial Fibrillation; Benzimidazoles; beta-Alanine; Brain Ischemia; Dabigatran; Double-Blind Method; Factor Xa Inhibitors; Fibrinolytic Agents; Heart Diseases; Hemorrhage; Humans; International Normalized Ratio; Intracranial Embolism; Multicenter Studies as Topic; Prevalence; Randomized Controlled Trials as Topic; Risk Factors; Single-Blind Method; Thrombophilia; Vitamin K

The vitamin K antagonists (VKA) available for stroke prevention in patients with atrial fibrillation have many drawbacks due to their difficult clinical use and high risk of bleeding. Currently, several drugs are being developed as possible substitutes for VKA that have many advantages such as the lack of monitoring requirement and scarce pharmacologic and food interactions. The present article provides an update on the new oral anticoagulants that are in a more advanced stage of clinical research, their pharmacologic properties, advantages and disadvantages and their results in recent clinical trials.

Topics: Administration, Oral; Anticoagulants; Azetidines; Benzimidazoles; Benzylamines; beta-Alanine; Clinical Trials as Topic; Dabigatran; Drug Monitoring; Drugs, Investigational; Hemorrhage; Humans; Morpholines; Multicenter Studies as Topic; Patient Care Planning; Pyrazoles; Pyridones; Randomized Controlled Trials as Topic; Rivaroxaban; Stroke; Thiophenes; Thrombophilia; Vitamin K

The standard multipotent anticoagulants (unfractionated and low molecular weight heparins, antagonists of vitamin K) are commonly used for treatment and/or prophylaxis of different thrombotic complications, such as deep vein thrombosis, thrombophilia, pulmonary embolism, myocardial infarction, stroke and so on. Advantages and shortcomings of these anticoagulants are considered. The modern tendencies to use small selective direct inhibitors of thrombin or factor Xa are surveyed. The search of the new targets in the coagulation cascade for development of new promising anticoagulants and improvement in antithrombotic therapy is discussed.

Topics: Anticoagulants; Benzimidazoles; beta-Alanine; Blood Coagulation; Dabigatran; Factor Xa; Factor Xa Inhibitors; Heparin, Low-Molecular-Weight; Hirudins; Humans; Platelet Aggregation Inhibitors; Thrombin; Thromboembolism; Thrombophilia; Venous Thrombosis; Vitamin K; Warfarin

New oral anticoagulant drugs are emerging as alternatives to warfarin for the prevention of stroke in patients with non-valvular atrial fibrillation. Two agents are direct factor Xa inhibitors (rivaroxaban and apixaban), and the third is a direct thrombin inhibitor (dabigatran). They have been separately compared to warfarin in large randomised trials. Our objective was to indirectly compare the three agents to each other for major efficacy and safety outcomes. Studies were assessed for comparability and the odds ratios of selected outcomes for each anticoagulant versus one another were estimated indirectly. The three cohorts differed significantly in terms of CHADS(2) score and the number of individuals with a past history of stroke, transient ischemic attack or systemic embolism. The estimated odds ratio of stroke or systemic embolism was 1.35 for rivaroxaban vs dabigatran 150 mg (p=0.04), 0.97 for rivaroxaban versus dabigatran 110 mg (p=0.81), 1.22 for apixaban versus dabigatran 150 mg (p=0.18), 0.88 for apixaban versus dabigatran 110 mg (p=0.34) and 0.90 for apixaban versus rivaroxaban (p=0.43). The estimated odds ratio of major bleeding was 1.10 for rivaroxaban versus dabigatran 150 mg (p=0.36), 1.28 for rivaroxaban versus dabigatran 110 mg (p=0.02), 0.74 for apixaban versus dabigatran 150 mg (p=0.004), 0.87 for apixaban versus dabigatran 110 mg (p=0.17) and 0.68 for apixaban versus rivaroxaban (p<0.001). In conclusion, the available data indicate no significant difference in efficacy between dabigatran 150 mg and apixaban for the prevention of stroke or systemic embolism in patients with non-valvular atrial fibrillation. It appears however that apixaban is associated with less major bleeding than dabigatran 150 mg or rivaroxaban and that rivaroxaban is less effective than dabigatran 150 mg in preventing stroke or systemic embolism. Such an indirect comparison should be used only to generate hypotheses which need to be tested in a dedicated randomised trial comparing the three drugs directly.

Topics: Aged; Anticoagulants; Antithrombins; Atrial Fibrillation; Benzimidazoles; beta-Alanine; Clinical Trials, Phase III as Topic; Dabigatran; Embolism; Factor Xa Inhibitors; Female; Heart Valve Diseases; Hemorrhage; Humans; Ischemic Attack, Transient; Male; Morpholines; Multicenter Studies as Topic; Pyrazoles; Pyridones; Randomized Controlled Trials as Topic; Rivaroxaban; Secondary Prevention; Severity of Illness Index; Stroke; Thiophenes; Thrombophilia; Vitamin K; Warfarin

Venous thrombosis typically involves the lower extremities. Rarely, it can occur in cerebral, splanchnic, or renal veins, with a frightening clinical impact. Other rare manifestations are upper-extremity deep vein thrombosis, that can complicate with pulmonary embolism and post-thrombotic syndrome, and retinal vein occlusion, significantly affecting the quality of life. This review is focused on venous thromboses at unusual extra-abdominal sites. Local infections or cancer are frequent in cerebral sinus-venous thrombosis. Upper-extremity deep vein thrombosis is mostly due to catheters or effort-related factors. Common risk factors are inherited thrombophilia and oral contraceptive use. Acute treatment is based on heparin; in cerebral sinus-venous thrombosis, local or systemic fibrinolysis should be considered in case of clinical deterioration. Vitamin-K antagonists are recommended for 3-6 months; indefinite anticoagulation is suggested for recurrent thrombosis or unprovoked thrombosis and permanent risk factors. However, such recommendations mainly derive from observational studies; there are no data about long-term treatment of retinal vein occlusion.

Topics: Anticoagulants; Catheters; Contraceptives, Oral; Heparin; Humans; Postthrombotic Syndrome; Pulmonary Embolism; Retinal Vein Occlusion; Risk Factors; Thrombophilia; Upper Extremity Deep Vein Thrombosis; Vitamin K; Warfarin

On of the most common, and serious, complications in cardiac surgery is postoperative bleeding. According to the majority of studies, between 10% and 92% of patients subjected to elective surgery require transfusions of blood products and blood derivatives. Transfusions and reinterventions are associated with longer stays in critical care units and a decrease in survival rates. There have been some important changes in the treatment of changes in haemostasis and post-surgical bleeding in the last few years, particularly with the introduction into clinical practice of working procedures backed up by clinical guidelines, as well as the appearance of new drugs. The aim of this work is to describe the main characteristics and update the use of prothrombin complexes that are currently available in Spain, with special emphasis on their use in cardiac surgery.

Topics: Anticoagulants; Blood Coagulation Factors; Blood Loss, Surgical; Blood-Borne Pathogens; Cardiac Surgical Procedures; Contraindications; Disease Transmission, Infectious; Drug Contamination; Drug Costs; Heart Diseases; Hemorrhagic Disorders; Hemostatics; Humans; Postoperative Hemorrhage; Preanesthetic Medication; Thrombophilia; Thrombosis; Vitamin K

Vitamin K antagonists and heparins have been standard anticoagulation drugs over the past decades. They are effective and safe but they have several drawbacks which has led to the development of new oral anticoagulants. Dabigatran etexilate is a specific oral thrombin inhibitor and rivaroxaban and apixaban are oral inhibitors of factor Xa. These agents produce a predictable anticoagulant response after fixed-dose administration so that routine coagulation monitoring is unnecessary. Currently, dabigatran etexilate, rivaroxaban and apixaban are licensed for thromboprophylaxis after elective total hip or knee replacement surgery. Since august 2011, dabigatran etexilate is licensed for patients with atrial fibrillation, rivaroxaban will follow. However, indications will be expanded e.g. for therapy of venous thromboembolism. It is important to be aware of the pharmacokinetic and pharmacodynamic profiles of these new agents. The drugs considerably influence the global test of coagulation thus making an interpretation of test results difficult. Currently, there is a lack of suitable coagulation tests to monitor anticoagulation in emergency cases, such as bleeding. Specific antidotes are not yet available.

Topics: Administration, Oral; Antithrombins; Arthroplasty, Replacement, Hip; Atrial Fibrillation; Benzimidazoles; Blood Coagulation Tests; Critical Care; Dabigatran; Drug Approval; Factor Xa Inhibitors; Fibrinolytic Agents; Hemorrhage; Heparin; Humans; Morpholines; Postoperative Complications; Pyrazoles; Pyridines; Pyridones; Rivaroxaban; Thiophenes; Thrombophilia; Vitamin K

The optimal course of oral anticoagulant therapy is determined according to the risk of recurrent venous thromboembolism after stopping therapy and the risk of anticoagulant-related bleeding. Clinical risk factors appear to be important in predicting the risk of recurrence whereas the influence of biochemical and morphological tests is uncertain. The risk of recurrent venous thromboembolism is low when the initial episode was provoked by a reversible major risk factor (surgery): 3 months of anticoagulation is sufficient. Conversely, the risk is high when venous thromboembolism was unprovoked or associated with persistent risk factor (cancer): 6 months or more prolonged anticoagulation is necessary. After this first estimation, the duration of anticoagulation may be modulated according to the presence or absence of certain additional risk factors (major thrombophilia, chronic pulmonary hypertension, massive pulmonary embolism): 6 months if pulmonary embolism was provoked and 12 to 24 months if pulmonary embolism was unprovoked. If the risk of anticoagulant-related bleeding is high, the duration of anticoagulation should be shortened (3 months if pulmonary embolism was provoked and 3 to 6 months if it was unprovoked). Lastly, if pulmonary embolism occurred in association with cancer, anticoagulation should be conducted for 6 months or more if the cancer is active or treatment is on going. Despite an increasing knowledge of the risk factors for recurrent venous thromboembolism, a number of issues remain unresolved. Randomised trials comparing different durations of anticoagulation are needed.

Topics: Age Factors; Anticoagulants; Antiphospholipid Syndrome; Cohort Studies; Drug Administration Schedule; Female; Fibrin Fibrinogen Degradation Products; Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Hypertension, Pulmonary; Male; Neoplasms; Prospective Studies; Pulmonary Embolism; Randomized Controlled Trials as Topic; Recurrence; Risk Factors; Sex Factors; Thrombophilia; Time Factors; Vena Cava Filters; Venous Thrombosis; Vitamin K

Heparins, either unfractionated or low-molecular-weight (UFH and LMWHs), and vitamin K antagonists (VKAs) are currently the anticoagulants of choice for the prevention of post-operative venous thromboembolism (VTE) and for the treatment of acute venous and arterial thromboembolism. While VKAs are widely used in the US, LMWHs are the standard of care in the EU. Although efficacious, these agents are associated with a number of drawbacks, such as the risk of heparin-induced thrombocytopenia, the need for frequent coagulation monitoring in the case of UFH and VKAs, and the parenteral mode of administration in the case of heparins, which can lead to problems associated with patient compliance. There is a need for new anticoagulants that overcome these limitations. Direct, small-molecule inhibitors of coagulation proteins targeting a single enzyme in the coagulation cascade - particularly thrombin or Factor Xa - have been developed in recent years. Two agents, the direct thrombin inhibitor dabigatran and the direct Factor Xa inhibitor rivaroxaban, have recently been approved in the EU and several other countries for the prevention of VTE after total hip or knee replacement surgery. Here we will review data that suggest that the antithrombin-independent mechanism of action of these agents, particularly that of direct Factor Xa inhibitors, leads to increased efficacy with similar safety profiles compared with the antithrombin-dependent heparins. Although the end of the heparins era is not to be expected, the new anticoagulants presented in this review potentially represent the future of anticoagulation.

Topics: Anticoagulants; Antithrombin III; Blood Coagulation Factors; Clinical Trials as Topic; Drug Design; Enzyme Inhibitors; Factor V; Factor Xa; Factor Xa Inhibitors; Hemorrhage; Heparin; Heparin, Low-Molecular-Weight; Humans; Molecular Weight; Postoperative Complications; Purpura, Thrombocytopenic, Idiopathic; Thrombophilia; Venous Thromboembolism; Vitamin K

Heparin-induced thrombocytopenia (HIT) is an immune-mediated disorder caused by the development of antibodies to platelet factor 4 (PF4) and heparin. The thrombocytopenia is typically moderate, with a median platelet count nadir of approximately 50 to 60 x 10(9) platelets/L. Severe thrombocytopenia has been described in patients with HIT, and in these patients antibody levels are high and severe clinical outcomes have been reported (eg, disseminated intravascular coagulation with microvascular thrombosis). The timing of the thrombocytopenia in relation to the initiation of heparin therapy is critically important, with the platelet count beginning to drop within 5 to 10 days of starting heparin. A more rapid drop in the platelet count can occur in patients who have been recently exposed to heparin (within the preceding 3 months), due to preformed anti-heparin/PF4 antibodies. A delayed form of HIT has also been described that develops within days or weeks after the heparin has been discontinued. In contrast to other drug-induced thrombocytopenias, HIT is characterized by an increased risk for thromboembolic complications, primarily venous thromboembolism. Heparin and all heparin-containing products should be discontinued and an alternative, non-heparin anticoagulant initiated. Alternative agents that have been used effectively in patients with HIT include lepirudin, argatroban, bivalirudin, and danaparoid, although the last agent is not available in North America. Fondaparinux has been used in a small number of patients with HIT and generally appears to be safe. Warfarin therapy should not be initiated until the platelet count has recovered and the patient is systemically anticoagulated, and vitamin K should be administered to patients receiving warfarin at the time of diagnosis of HIT.

Topics: Anticoagulants; Arginine; Autoantibodies; Contraindications; Disseminated Intravascular Coagulation; Fondaparinux; Heparin; Hirudins; Humans; Pipecolic Acids; Platelet Count; Platelet Factor 4; Polysaccharides; Recombinant Proteins; Sulfonamides; Thrombocytopenia; Thrombophilia; Time Factors; Venous Thromboembolism; Vitamin K; Warfarin

Cancer is linked with hypercoagulability and risk of thrombosis and this close association was recognized by Armand Trousseau in 1865. The relation between cancer and blood coagulation is reciprocal: cancer induces a hypercoagulable state and predisposes to thrombosis and activation of platelets, blood coagulation and fibrinolysis interfere with tumor cell biology, tumor growth, angiogenesis and metastatic process. In the present article, we analyze the clinical trials which assessed the influence of anticoagulant treatment on the survival of patients with cancer. The available data show that low-molecular-weight heparins (LMWHs) tend to be more effective and safer than vitamin K antagonists (VKA) in improving survival in patients with cancer. The beneficial effect of anticoagulation with either LMWHs or VKA is not universal for all patients with cancer. There are some histological types of cancers which, at early stages, appear to be more sensitive than others to the effect of anticoagulant treatment. The available clinical trials, although limited, are encouraging for the beneficial effect of anticoagulant treatment on the survival of cancer patients. More clinical trials are needed, targeting groups of patients homogenous regarding the type of cancer, the stage of the disease and life expectancy. The forthcoming clinical trials have to address some issues regarding the optimal dose, the timing and the duration of treatment with LMWH in relation to chemotherapy or other anticancer therapies.

Topics: Animals; Anticoagulants; Clinical Trials as Topic; Double-Blind Method; Drug Screening Assays, Antitumor; Fibrinolytic Agents; Hemorrhage; Heparin; Heparin, Low-Molecular-Weight; Humans; Meta-Analysis as Topic; Mice; Multicenter Studies as Topic; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Randomized Controlled Trials as Topic; Research Design; Survival Analysis; Thrombophilia; Thrombosis; Vitamin K; Warfarin

In the mid-19th century, Virchow identified hypercoagulability as part of the triad leading to venous thrombosis, but the specific causes of hypercoagulability remained a mystery for another century. The first specific cause to be identified was antithrombin III deficiency. Many other causes of thrombophilia, both genetic and acquired, have been discovered since then. The 2 most common genetic causes of thrombophilia are the Leiden mutation of factor V and the G20210A mutation of prothrombin. The most common acquired cause is antiphospholipid syndrome. These factors increase the relative risk of an initial episode of venous thromboembolism (VTE) by a factor of 2 to 10, but the actual risk remains relatively modest. Therefore, thrombophilia screening to prevent initial episodes of VTE is not indicated, except possibly in women with a family history of idiopathic VTE who are considering oral contraceptive therapy. Some physicians screen for thrombophilia to aid decision making concerning the duration of anticoagulant therapy. However, several studies have demonstrated that, with the exception of antiphospholipid syndrome, thrombophilia does not significantly increase the risk of recurrent VTE. On the other hand, idiopathic VTE significantly increases the risk of recurrence in patients with or without thrombophilia.

Topics: Anticoagulants; Factor V; Humans; Hyperhomocysteinemia; Mass Screening; Recurrence; Risk Assessment; Risk Factors; Thromboembolism; Thrombophilia; Vitamin K; Warfarin

Topics: Anticoagulants; Azetidines; Benzylamines; Clinical Trials, Phase III as Topic; Drug Design; Factor Xa Inhibitors; Follow-Up Studies; Fondaparinux; Humans; Polysaccharides; Randomized Controlled Trials as Topic; Recurrence; Thromboembolism; Thrombophilia; Venous Thrombosis; Vitamin K

It is now possible to identify hereditary risk factors in a substantial percentage of patients presenting with a venous thrombotic event. Discovery of the factor V Leiden and prothrombin G20210A mutations has greatly increased the percentage of patients in whom venous thrombosis can be attributed to hereditary thrombophilia. There is considerable uncertainty, however, as to how this information should be used in patient management. Although prolonged anticoagulation at an international normalized ratio (INR) of 2 to 3 is highly effective in preventing thrombotic recurrences, this benefit is partially offset by the risk of major bleeding and the inconvenience associated with oral vitamin K antagonists. Although low-intensity anticoagulation at a target INR of 1.5 to 2 has recently been shown to be effective in preventing recurrent venous thromboembolism after 3 to 6 months of treatment at an INR of 2 to 3, it has not been demonstrated to reduce the risk of major bleeding complications. A decision as to the overall benefit of extended anticoagulation therefore continues to require clinical assessment of an individual patient's risk of recurrence in the absence of treatment and the risk of bleeding at the chosen INR target range.

Topics: Anticoagulants; Factor V; Humans; International Normalized Ratio; Mutation; Prothrombin; Recurrence; Risk; Risk Factors; Thromboembolism; Thrombophilia; Time Factors; Venous Thrombosis; Vitamin K; Warfarin

Topics: Anticoagulants; Female; Humans; Platelet Aggregation Inhibitors; Thrombophilia; Vitamin K

Topics: Adenocarcinoma; Anticoagulants; Carcinoma, Small Cell; Clinical Trials as Topic; Colorectal Neoplasms; Heparin; Humans; Lung Neoplasms; Neoplasms; Odds Ratio; Thrombophilia; Vitamin K

The optimal duration of oral anticoagulant therapy after a first episode of venous thromboembolism is still a matter of debate. It is essential to balance the desired effect of the anticoagulants in reducing recurrences against the risk of major bleeding. The aims of this paper are to describe the current concepts in this field.. Recent data, based on randomised controlled trials, suggest that it is necessary to tailor the duration of anticoagulation individually according to the topography of venous thromboembolism and the presence of risk factors. A 6-week treatment for patients with isolated calf vein thrombosis is sufficient. For proximal thrombosis and/or pulmonary embolism, a short anticoagulant course seems sufficient in patients with temporary risk factors (3 months) and a longer anticoagulant course (6 months at least) is recommended for cases with permanent risk factors or idiopathic venous thromboembolism. The inherited or acquired hypercoagulable states can be divided into those that are common and associated with a modest risk of recurrence (i.e., isolated factor V Leiden or G20210A prothrombin gene) and those that are uncommon but associated with a high risk of recurrence (i.e., antithrombin, protein C or S deficiencies and anticardiolipin antibodies). Thus, the presence of one of these last abnormalities favours more prolonged anticoagulant therapy.. 1) For patients at high risk of recurrence, there is a paucity of evidence-based medicine, particularly for patients with biological thrombophilia, and randomised controlled trials in this population are required. An assessment of low- or fixed-dose oral anticoagulation is also necessary in order to reduce the bleeding risk. 2) It is not always possible to precisely determine the optimal duration with the available data. We have performed a meta-analysis on summary data which suggests that a long course of oral anticoagulant therapy is superior to a short course. An individual meta-analytic approach is needed to draw more precise conclusions on an interesting and important clinical topic and we propose to perform this analysis in a international collaborative group.

Topics: Administration, Oral; Aged; Anticoagulants; Humans; Iatrogenic Disease; Meta-Analysis as Topic; Prospective Studies; Pulmonary Embolism; Randomized Controlled Trials as Topic; Recurrence; Risk Factors; Thromboembolism; Thrombophilia; Time Factors; Venous Thrombosis; Vitamin K

Over the last 30 years, a growing body of evidence has documented the role of hyperhomocysteinemia (HHcy) as an independent vascular risk factor. However, the mechanisms through which elevated circulating levels of homocysteine (Hcy) cause vascular injury and promote thrombosis remain elusive. Most findings have been achieved in in vitro studies employing exceedingly high concentrations of Hcy, whereas only a few studies have been carried out in vivo in humans. In homocystinuric patients, homozygotes for mutations of the gene coding for the cystathionine beta-synthase enzyme, abnormalities of coagulation variables reflecting a hypercoagulable state, have been reported. In vitro studies provide a biochemical background for such a state. In homocystinuric patients, an in vivo platelet activation has also been reported. The latter abnormality is not corrected by the bolus infusion of concentrations of hirudin, which determines a long-lasting impairment of the conversion of fibrinogen to fibrin by thrombin; in contrast, it appears at least in part lowered by the administration of the antioxidant drug probucol. During the autooxidation of Hcy in plasma, reactive oxygen species are generated. The latter initiate lipid peroxidation in cell membranes (potentially responsible for endothelial dysfunction) and in circulating lipoproteins. Oxidized low-density lipoproteins (LDL) may trigger platelet activation as well as some of the hemostatic abnormalities reported in such patients. Thus the oxidative stress induced by Hcy may be a key process in the pathogenesis of thrombosis in HHcy. Accumulation of adenosylhomocysteine in cells (a consequence of high circulating levels of homocysteine) inhibits methyltransferase enzymes, in turn preventing repair of aged or damaged cells. This mechanism has been recently documented in patients with renal failure and HHcy and provides an additional direction to be followed to understand the tendency to thrombosis in moderate HHcy.

Topics: Adolescent; Adult; Arteriosclerosis; Blood Coagulation; Cardiovascular Diseases; Cellular Senescence; Child; Endothelium, Vascular; Female; Genetic Predisposition to Disease; Homocysteine; Homocystinuria; Humans; Hyperhomocysteinemia; Lipid Peroxidation; Lipoproteins, LDL; Male; Methyltransferases; Oxidation-Reduction; Platelet Activation; Reactive Oxygen Species; Renal Insufficiency; Risk Factors; S-Adenosylhomocysteine; Thrombophilia; Thromboxane B2; Vitamin K

There is considerable evidence that the hemostatic system is involved in the growth and spread of malignant disease. There is an increased incidence of thromboembolic disease in patients with cancers and hemostatic abnormalities are extremely common in such patients. Antihemostatic agents have been successfully used to treat a variety of experimental tumors, and several clinical trials in humans have been initiated. Although metastasis is undoubtedly multifactorial, intravascular coagulation activation and peritumor fibrin deposition seem to be important. The mechanisms by which hemostatic activation facilitates the malignant process remain to be completely elucidated. Of central importance may be the presence on malignant cells of tissue factor and urokinase receptor. Recent studies have suggested that these proteins, and others, may be involved at several stages of metastasis, including the key event of neovascularization. Tissue factor, the principal initiator of coagulation, may have additional roles, outside of fibrin formation, that are central to the biology of some solid tumors.

Topics: Animals; Anticoagulants; Antineoplastic Agents; Biomarkers; Blood Coagulation Tests; Cell Adhesion; Cysteine Endopeptidases; Disseminated Intravascular Coagulation; Factor Xa; Fibrin; Fibrinolysis; Hemostasis; Heparin; Humans; Monocytes; Neoplasm Metastasis; Neoplasm Proteins; Neoplasms; Neoplasms, Experimental; Neoplastic Cells, Circulating; Neovascularization, Pathologic; Platelet Activation; Platelet Aggregation Inhibitors; Receptors, Thrombin; Thrombophilia; Thrombophlebitis; Thromboplastin; Vitamin K

Rivaroxaban is a new oral anticoagulant (NOAC) that can be prescribed in a fixed dose, making regular monitoring and dose adjustments unnecessary. It has been proven to be safe and effective in comparison with enoxaparin/vitamin K antagonists (LMWH/VKA) for the (extended) treatment of venous thromboembolism in the EINSTEIN studies. Nevertheless, there is a need for information regarding the clinical impact of (major) bleeding events with NOACs such as rivaroxaban.. A post-hoc analysis was performed to compare the severity of clinical presentation and subsequent clinical course of major bleeding with rivaroxaban vs. LMWH/VKA.. Two investigators performed a blinded classification of major bleeding using a priori defined criteria. During the EINSTEIN studies, data concerning the clinical course and measures applied were prospectively collected for each major bleed.. Treatment with LMWH/VKA caused more major bleeding events (1.7%) than rivaroxaban (1.0%; hazard ratio, 0.54; 95% confidence interval [CI], 0.37-0.79). Major bleeding events during rivaroxaban therapy had a milder presentation (23% were adjudicated to the worst categories vs. 38% for LMWH/VKA; hazard ratio or HR, 0.35; 95% CI, 0.17-0.74; P = 0.0062). The clinical course was severe in 25% of all major bleeding events associated with rivaroxaban, compared with 33% of LMWH/VKA-associated bleeds (HR, 0.46; 95% CI, 0.22-0.96; P = 0.040).. Rivaroxaban-associated major bleeding events occurred less frequently, had a milder presentation and appeared to take a less severe clinical course compared with major bleeding with LMWH/VKA.

Topics: Anticoagulants; Blood Coagulation Factors; Factor VIIa; Factor Xa Inhibitors; Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Kaplan-Meier Estimate; Plasma; Prospective Studies; Pulmonary Embolism; Recombinant Proteins; Rivaroxaban; Severity of Illness Index; Single-Blind Method; Thrombophilia; Venous Thrombosis; Vitamin K

Vitamin K antagonists (VKA) are used to prevent recurrent disease in patients with venous thromboembolism (VTE). Their efficacy and safety depend on individual time in therapeutic range (iTTR) and variability of International Normalised Ratios (INR). We aimed to identify independent predictors of poor VKA control > 28 days. In a prospective cohort of 3825 VTE patients, separate logistic regression analyses were performed to identify predictors of low iTTR (first quartile) and instability (iTTR median). Subsequently, the association between these predictors and clinical outcomes was investigated. Weight < 50 kg (odds ratio [OR]=1.89; 95 % confidence interval [CI] 1.03-3.49), active cancer at baseline (OR=1.52; CI1.05-2.19), secondary VTE (OR=1.42; CI1.20-1.68), and INR < 2.0 at stop of double therapy (OR=1.35; CI1.09-1.67) were independent predictors of low iTTR. The first two were also predictive for instability (OR=1.96; CI1.06-3.63 and OR=1.95; CI1.36-2.80, respectively). ORs of early (≤ 28 days) low iTTR and instability depended on VKA type. In acenocoumarol users, early low iTTR was an independent predictor of subsequent low iTTR (OR=1.92; CI1.31-2.80) and instability (OR=1.55; CI1.07-2.23). In warfarin users, early low iTTR (OR=1.36; CI1.09-1.69) and instability (OR=1.25; CI1.01-1.55) were additionally predictive for low iTTR, but only the latter was predictive for instability (OR=1.91; CI1.57-2.32). Many predictors of VKA control also predicted premature discontinuation, but only region was prognostic for clinical outcome. In conclusion, we identified several independent predictors of low iTTR and instability > 28 days, which showed some similarities but did not fully overlap. Early VKA control was of additional value for prediction of both, but had to be interpreted in the context of VKA type.

Topics: Acenocoumarol; Administration, Oral; Aged; Anticoagulants; Drug Therapy, Combination; Enoxaparin; Female; Hemorrhage; Humans; International Normalized Ratio; Male; Middle Aged; Neoplasms; Prognosis; Recurrence; Risk Factors; Thrombophilia; Treatment Outcome; Venous Thromboembolism; Vitamin K; Warfarin

Topics: Cardiolipins; Factor V; Genetic Predisposition to Disease; Humans; Mutation; Phlebography; Plasminogen Activator Inhibitor 1; Polymorphism, Single Nucleotide; Prothrombin; Pulmonary Embolism; Risk; Thrombophilia; Venous Thrombosis; Vitamin K

During commencement of oral anticoagulant therapy (OAT) a theoretical possibility of a transient hypercoagulable state emerges from the difference in plasma half-life between the vitamin K-dependent pro-coagulation factors II and X, and the vitamin K-dependent anticoagulant proteins C and S. In the present study, markers reflecting the activity in the haemostatic system (prothrombin fragment 1+2 [F1+2], D-dimer and soluble fibrin) was assessed during initiation of OAT compared to subcutaneously administered low-molecular weight heparin (LMWH) which does not cause any imbalance between the concentrations of the pro- and anticoagulation proteins.. Thirty-three patients with atrial fibrillation were randomly treated either with OAT (warfarin 10, 7.5, and 5 mg for three consecutive days) or LMWH administered in a fixed dose of 200 anti-Xa IU/kg body weight in one subcutaneous injection daily. The biochemical markers were measured at baseline, and after 12, 36 and 60 h of treatment.. After introducing antithrombotic therapy, none of the biochemical markers increased within the study period in the two treatment groups. The level of F1+2 had declined significantly at 60 h in both groups. The level of soluble fibrin showed a significant decrease within the first 60 h in the OAT group, and no significant changes were seen in the LMWH group. No significant change in the level of D-dimer was seen during the first 60 h of treatment in either group. Taken together, no transient hypercoagulable state could be identified within the first 60 h of commencing OAT in patients with atrial fibrillation.

Topics: Administration, Oral; Aged; Atrial Fibrillation; Biomarkers; Blood Coagulation Factors; Dalteparin; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinolytic Agents; Half-Life; Humans; Male; Middle Aged; Peptide Fragments; Prothrombin; Stroke; Thrombophilia; Time Factors; Vitamin K; Warfarin

It is yet unclear whether vitamin K antagonist treatment should be stopped abruptly or gradually after an episode of venous thromboembolism. The mode of withdrawal might influence a potential development of a hypercoagulable state, which could influence the risk for recurrent disease.. We prospectively studied 37 consecutive patients in whom acenocoumarol was discontinued either abrupt (18) or gradually (19) (2/3 and 1/3 of the initial dose for one week). Blood sampling was performed at various time points up to 18 days after complete withdrawal and was analysed for INR, prothrombin fragment F1 + 2 and D-dimer. All patients were clinically followed-up for the assessment of the association between hypercoagulability and occurrence of disease such as recurrent venous thromboembolism or malignancy.. An approximately fourfold increase was observed (median increase from 0.3 to 1.3 nmol/l) in the F1 + 2 levels after both abrupt and gradual withdrawal and in the D-dimer concentrations in the abrupt withdrawal group (0.10 to 0.44 mg/l), while those in whom acenocoumarol was discontinued gradually showed a less pronounced increase of the D-dimer levels (0.11 to 0.29 mg/L) (not significant). During follow-up one recurrent venous thromboembolic event occurred in each group, and a diagnosis of cancer was made four times. All these patients had the highest D-dimer concentrations measured in the entire study group.. This study indicates the potential for a hypercoagulable state after acenocoumarol discontinuation, which was not prevented by tapering the acenocoumarol dose. D-dimer, measured 2 to 3 weeks after acenocoumarol withdrawal, might be an important tool to identify patients at risk for recurrent venous thromboembolism and/or for the presence of an underlying malignancy.

Topics: Acenocoumarol; Adolescent; Adult; Aged; Anticoagulants; Drug Administration Schedule; Female; Humans; Male; Middle Aged; Thromboembolism; Thrombophilia; Venous Thrombosis; Vitamin K

Warfarin is employed more frequently than acenocoumarol because of its longer half-life (36 h), theoretically providing more stable anticoagulation, and avoiding factor VII fluctuations that potentially occur during acenocoumarol treatment (half-life 10 h). The aim of our study was to compare acenocoumarol with warfarin in the same group of 103 patients who started oral anticoagulation with acenocoumarol and then changed to warfarin. In these patients we compared the previous period of six months on acenocoumarol treatment (July-December 1996) with a new six-month period on warfarin (July-December 1997). We wished to know whether warfarin could improve the quality and the stability of oral anticoagulation of our patients and whether there was a difference between the two drugs in the weekly mean dose per patient. Moreover in order to detect the possible daily fluctuation of factor VII, we evaluated a further group of 54 patients. A subgroup of these patients was treated with warfarin while another received acenocoumarol. In the first group of patients, 1,158 and 1,064 PTs were carried out with acenocoumarol and warfarin, respectively. The percentage of PTs in the therapeutic range was 59% with acenocoumarol and 62% with warfarin (p=0.4). The mean number of visits per patient was 12 and 11, and the mean number of visits in the therapeutic range was 7 and 7, respectively. The last check in file method did not show any difference between the two drugs. Overdose states were 51 (4.4%) with acenocoumarol and 30 (2.8%) with warfarin (p=0.4). A good correlation (r=0.92) was found between the acenocoumarol and the warfarin weekly mean dose. The mean warfarin/acenocoumarol weekly dose ratio was 2.08 (range: 1.25-3.30; CI 95%: 1.99-2.16). In the second group of patients, factor VII levels with both drugs were higher 24 h after administration than 16 h after, showing that their daily fluctuation was independent of the drug's half-life, since factor VII levels in patients with a low vitamin K intake were not increased. Our results showed that warfarin did not appear to be better than acenocoumarol in the performance of an Anticoagulation Clinic in terms of PTs within the therapeutic range per patient. It seems that the behaviour of factor VII was affected by the intake of vitamin K rather than by the short half-life of acenocoumarol.

Topics: Acenocoumarol; Administration, Oral; Adult; Aged; Anticoagulants; Cross-Over Studies; Dose-Response Relationship, Drug; Factor VII; Female; Humans; Male; Middle Aged; Prothrombin Time; Thrombophilia; Treatment Outcome; Vitamin K; Warfarin

Monitoring of vitamin K antagonist treatment with the international normalized ratio (INR) is obligatory, whereas this only applies to direct oral anticoagulants (DOAC) or low molecular weight heparin in the context of selected clinical scenarios. For DOAC the focus is on the determination of trough and peak plasma levels of the drug but for low molecular weight heparins the focus is on anti-Xa activity. The timing of blood sampling in relation to drug intake is essential for the interpretation of the results. A new-onset thrombocytopenia during hospitalization is common. The cause can frequently be identified based on the classification of the underlying disease, the day of onset and documentation of the dynamics of thrombocytopenia as well as the medication history. The importance of thrombophilia testing following a venous thromboembolism has decreased in the absence of clear therapeutic consequences; however, antiphospholipid antibody syndrome must not be overlooked as both the duration of treatment and the choice of anticoagulant depend on this.. Während bei einer Vitamin-K-Antagonisten-Therapie die Therapieüberwachung (International Normalized Ratio [INR]) obligat ist, gilt dies für direkte orale Antikoagulanzien (DOAK) oder niedermolekulares Heparin (NMH) nur in ausgewählten klinischen Szenarien. Bei DOAK steht die Bestimmung von Tal- und Spitzenspiegeln des Medikaments im Plasma im Vordergrund, bei NMH die Anti-Xa-Aktivität. Der Zeitpunkt der Probenabnahme in Relation zur Einnahme ist für die Bewertung essenziell. Eine neu aufgetretene Thrombozytopenie im Rahmen stationärer Behandlungen ist häufig. Einordnung der Grunderkrankung, Tag des Auftretens sowie Erfassung medikamentöser Einflüsse und ihrer Dynamik ermöglichen oft die Eingrenzung der Ursache. Die Thrombophilietestung nach venöser Thromboembolie wird aufgrund fehlender therapeutischer Konsequenz zunehmend seltener durchgeführt. Ein Antiphospholipidsyndrom darf aber nicht übersehen werden, da sowohl die Therapiedauer als auch die Wahl des Antikoagulans davon abhängen.

Topics: Anticoagulants; Heparin, Low-Molecular-Weight; Humans; Thrombocytopenia; Thrombophilia; Vitamin K

Evidence for the efficacy of direct oral anticoagulants (DOACs) to prevent cardiovascular (CV) events and mortality in older individuals with a low estimated glomerular filtration rate (eGFR) is lacking. We sought to characterize the association of oral anticoagulant use with CV morbidity in elderly patients with or without reductions in eGFRs, comparing DOACs with vitamin K antagonists (VKAs).. Population-based retrospective cohort study.. All individuals 66 years or older with an initial prescription for oral anticoagulants dispensed in Ontario, Canada, from 2009 to 2016.. DOACs (apixaban, dabigatran, and rivaroxaban) compared with VKAs by eGFR group (≥60, 30-59, and<30mL/min/1.73m. The primary outcome was a composite of a CV event (myocardial infarction, revascularization, or ischemic stroke) or mortality. Secondary outcomes were CV events alone, mortality, and hemorrhage requiring hospitalization.. High-dimensional propensity score matching of DOAC to VKA users and Cox proportional hazards regression.. 27,552 new DOAC users were matched to 27,552 new VKA users (median age, 78 years; 49% women). There was significantly lower risk for CV events or mortality among DOAC users compared with VKA users (event rates of 79.78 vs 99.77 per 1,000 person-years, respectively; HR, 0.82 [95% CI, 0.75-0.90]) and lower risk for hemorrhage (event rates of 10.35 vs 16.77 per 1,000 person-years, respectively; HR, 0.73 [95% CI, 0.58-0.91]). There was an interaction between eGFR and the association of anticoagulant class with the primary composite outcome (P<0.02): HRs of 1.01 [95% CI, 0.92-1.12], 0.83 [95% CI, 0.75-0.93], and 0.75 [95% CI, 0.51-1.10] for eGFRs of≥60, 30 to 59, and<30mL/min/1.73m. Retrospective observational study design limits causal inference; dosages of DOACs and international normalized ratio values were not available; low event rates in some subgroups limited statistical power.. DOACs compared with VKAs were associated with lower risk for the composite of CV events or mortality, an association for which the strength was most apparent among those with reduced eGFRs. The therapeutic implications of these findings await further study.

Topics: Aged; Aged, 80 and over; Antithrombins; Brain Ischemia; Cause of Death; Comorbidity; Dabigatran; Female; Glomerular Filtration Rate; Hemorrhage; Humans; Male; Mortality; Myocardial Infarction; Myocardial Revascularization; Ontario; Procedures and Techniques Utilization; Propensity Score; Proportional Hazards Models; Pyrazoles; Pyridones; Renal Insufficiency, Chronic; Retrospective Studies; Rivaroxaban; Thrombophilia; Vitamin K

Topics: 4-Hydroxycoumarins; Adult; Aftercare; Anticoagulants; Antiphospholipid Syndrome; England; Factor Xa Inhibitors; Fibrin Fibrinogen Degradation Products; Heparin, Low-Molecular-Weight; Humans; Incidence; Indenes; International Normalized Ratio; Neoplasms; Pyrazoles; Pyridones; Risk Assessment; Rivaroxaban; State Medicine; Systematic Reviews as Topic; Thrombophilia; Vena Cava Filters; Venous Thromboembolism; Vitamin K

Background In this prospective cohort study, we aimed to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) versus heparin/vitamin K antagonists for the treatment of venous thromboembolism (VTE) in patients with inherited thrombophilia. Methods and Results We enrolled consecutive patients with acute VTE and inherited thrombophilia treated with DOACs (cases) or heparin/vitamin K antagonists (controls), matched for age, sex, ethnicity, and thrombophilia type. End points were VTE recurrence and bleeding complications; residual vein thrombosis and post-thrombotic syndrome; VTE recurrence after anticoagulant discontinuation. Two hundred fifty-five cases (age 52.4±17.3 years, Female 44.3%, severe thrombophilia 33.1%) and 322 controls (age 49.7±18.1 years, Female 50.3%, severe thrombophilia 35.1%) were included. The cumulative incidence of VTE recurrence during anticoagulation was 1.09% in cases versus 1.83%, adjusted hazard ratio (HR) 0.67 (95% CI, 0.16-2.77). The cumulative incidence of bleeding was 10.2% in cases versus 4.97%, HR 2.24 (95% CI 1.10-4.58). No major bleedings occurred in cases (versus 3 in controls). No significant differences regarding residual vein thrombosis and post-thrombotic syndrome. After anticoagulant discontinuation, DOACs yielded a significantly lower 2-year VTE recurrence risk versus traditional anticoagulants (HR, 0.61 [95% CI, 0.47-0.82]). Conclusions DOACs and heparin/vitamin K antagonists showed a similar efficacy in treating VTE in patients with thrombophilia. Although major bleeding episodes were recorded solely with heparin/vitamin K antagonists, we noted an overall increased bleeding rate with DOACs. The use of DOACs was associated with a lower 2-year risk of VTE recurrence after anticoagulant discontinuation.

Topics: Administration, Oral; Adult; Factor Xa Inhibitors; Female; Heparin, Low-Molecular-Weight; Humans; Incidence; Male; Middle Aged; Prospective Studies; Recurrence; Thrombophilia; Venous Thromboembolism; Vitamin K

Managing severe valvular heart disease with mechanical valve replacement necessitates lifelong anticoagulation with a vitamin K antagonist. Optimal anticoagulation intensity for patients with mechanical valves remains uncertain; current recommendations are inconsistent across guideline bodies and largely based on expert opinion. In this review, we outline the history of anticoagulation therapy in patients with mechanical heart valves and critically evaluate current antithrombotic guidelines for these patients. We conclude that randomized trials evaluating optimal anticoagulation intensity in patients with mechanical valves are needed, and that future guidelines must better justify antithrombotic treatment recommendations.

Topics: Anticoagulants; Atrial Fibrillation; Drug Monitoring; Health Services Needs and Demand; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Hemorrhage; History, 20th Century; History, 21st Century; Humans; Multicenter Studies as Topic; Postoperative Complications; Practice Guidelines as Topic; Randomized Controlled Trials as Topic; Thrombophilia; Vitamin K

Essentials A pediatric pharmacogenetic dosing algorithm for acenocoumarol has not yet been developed. We conducted a multicenter retrospective follow-up study in children in the Netherlands. Body surface area and indication explained 45.0% of the variability in dose requirement. Adding the genotypes of VKORC1, CYP2C9 and CYP2C18 to the algorithm increased this to 61.8%.. Background The large variability in dose requirement of vitamin K antagonists is well known. For warfarin, pediatric dosing algorithms have been developed to predict the correct dose for a patient; however, this is not the case for acenocoumarol. Objectives To develop dosing algorithms for pediatric patients receiving acenocoumarol with and without genetic information. Methods The Children Anticoagulation and Pharmacogenetics Study was designed as a multicenter retrospective follow-up study in Dutch anticoagulation clinics and children's hospitals. Pediatric patients who used acenocoumarol between 1995 and 2014 were selected for inclusion. Clinical information and saliva samples for genotyping of the genes encoding cytochrome P450 (CYP) 2C9, vitamin K epoxide reductase complex subunit 1 (VKORC1), CYP4F2, CYP2C18 and CYP3A4 were collected. Linear regression was used to analyze their association with the log mean stable dose. A stable period was defined as three or more consecutive International Normalized Ratio measurements within the therapeutic range over a period of ≥ 3 weeks. Results In total, 175 patients were included in the study, of whom 86 had a stable period and no missing clinical information (clinical cohort; median age 8.9 years, and 49% female). For 80 of these 86 patients, genetic information was also available (genetic cohort). The clinical algorithm, containing body surface area and indication, explained 45.0% of the variability in dose requirement of acenocoumarol. After addition of the VKORC1, CYP2C9, and CYP2C18 genotypes to the algorithm, this increased to 61.8%. Conclusions These findings show that clinical factors had the largest impact on the required dose of acenocoumarol in pediatric patients. Nevertheless, genetic factors, and especially VKORC1, also explained a significant part of the variability.

Topics: Acenocoumarol; Adolescent; Age Factors; Algorithms; Anticoagulants; Biological Variation, Individual; Biotransformation; Body Surface Area; Child; Child, Preschool; Cytochrome P-450 Enzyme System; Dose-Response Relationship, Drug; Female; Follow-Up Studies; Genetic Association Studies; Humans; Infant; Male; Models, Biological; Polymorphism, Single Nucleotide; Practice Guidelines as Topic; Retrospective Studies; Saliva; Thrombophilia; Vitamin K

: Activated protein C resistance (APC-R) is assessed as part of thrombophilia screening, preferably in patients not taking oral anticoagulants. Rivaroxaban is known to alter some APC-R assays. To our knowledge, there have been no reports on the effect of rivaroxaban on the Russell viper venom time (RVVT)-based APC-R assay in real-life patients. In 168 consecutive outpatients suspected of having venous thromboembolism because of thrombophilia, APC-R was determined using the RVVT-based ProC Ac R assay (Siemens, Marburg, Germany). Patients receiving rivaroxaban or vitamin K antagonists were eligible. We measured rivaroxaban concentrations using the anti-Xa Biophen DiXal assay (Hyphen Biomed, Neuville-Sur-Oise, France) and factor V Leiden using the real-time PCR. APC-R was detected in 23 (28%) patients on rivaroxaban (n = 81) administrated 2-48 h since the blood draw, 15 (28%) patients on vitamin K antagonists (n = 54), and in four (12%) patients off anticoagulation (n = 33). Compared with nonanticoagulated patients, APC-R ratios were similar in patients on rivaroxaban, without any correlation with rivaroxaban concentrations (from 0 to 303 μg/l). None of the patients on rivaroxaban were found to have false-negative or false-positive APC-R ratios. Rivaroxaban concentrations up to 300 μg/l do not affect results of the ProC Ac R RVVT-based assay, which could be recommended in patients referred to a clinic for thrombophilia screening in whom the time since the last dose of rivaroxaban is uncertain.

Topics: Activated Protein C Resistance; Adult; Factor Xa Inhibitors; Female; Humans; Male; Middle Aged; Prothrombin Time; Rivaroxaban; Thrombophilia; Venous Thromboembolism; Vitamin K

Guidelines describing the perioperative management of antithrombotic therapy in patients requiring temporary interruption of vitamin K antagonists (VKAs) were first published in 2008. The objective of this study is to evaluate the perioperative management of anticoagulation of patients on chronic VKA and the incidence of bleeding and thrombotic complications pre and postpublication of the 2008 American College of Chest Physicians (ACCP) guidelines. A retrospective review of 40 patients on chronic VKA requiring temporary discontinuation of VKA due to an invasive or surgical procedure who were referred to a single haematology practice from January 2006 to June 2010. Demographics, indications of VKA, risk factors for thrombosis, type of procedure, bridging regimen and bleeding complications were recorded pre and post-2008 ACCP guidelines. Sixty-one procedures were performed in 40 patients; 60% were women. Indications for anticoagulation were secondary prevention of venous thrombosis (n = 27), arterial thrombosis (n = 8) or both arterial thrombosis and venous thrombosis (n = 4), and primary prevention of arterial thrombosis (n = 1). Twenty patients (50%) had thrombophilia. The most common surgical and invasive procedures were gastrointestinal (33%), gynaecological (15%) and orthopaedic (11%). Bridging regimen with therapeutic-dose subcutaneous low molecular heparin (LMWH) was used in 27 (67.5%) patients, prophylactic-dose LMWH in 12 (30%) and a combination of LMWH therapeutic and prophylactic-dose doses in 11 (27.5%). Three bleeding complications occurred prepublication of the 2008 ACCP practice guidelines, although no bleeding complications occurred after the guidelines were published. Adherence to the 2008 ACCP guidelines for the perioperative management of anticoagulation reduced bleeding complications in patients on chronic VKA treatment.

Topics: Adult; Aged; Aged, 80 and over; Anticoagulants; Female; Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Male; Middle Aged; Patient Compliance; Perioperative Care; Practice Guidelines as Topic; Retrospective Studies; Risk Factors; Thrombophilia; Thrombosis; Venous Thrombosis; Vitamin K; Young Adult

Topics: Adult; Aged; Anticoagulants; Atrial Fibrillation; Electric Countershock; Embolism; Factor Xa Inhibitors; Heart Diseases; Hemorrhage; Humans; International Normalized Ratio; Middle Aged; Morpholines; Multicenter Studies as Topic; Myocardial Infarction; Prospective Studies; Randomized Controlled Trials as Topic; Research Design; Risk; Rivaroxaban; Stroke; Thiophenes; Thrombophilia; Time Factors; Treatment Outcome; Vitamin K; Warfarin

The safety and effectiveness of non-vitamin K antagonist (VKA) oral anticoagulants, dabigatran or rivaroxaban, were compared with VKA in anticoagulant-naive patients with nonvalvular atrial fibrillation during the early phase of anticoagulant therapy.. With the use of the French medico-administrative databases (SNIIRAM and PMSI), this nationwide cohort study included patients with nonvalvular atrial fibrillation who initiated dabigatran or rivaroxaban between July and November 2012 or VKA between July and November 2011. Patients presenting a contraindication to oral anticoagulants were excluded. Dabigatran and rivaroxaban new users were matched to VKA new users by the use of 1:2 matching on the propensity score. Patients were followed for up to 90 days until outcome, death, loss to follow-up, or December 31 of the inclusion year. Hazard ratios of hospitalizations for bleeding and arterial thromboembolic events were estimated in an intent-to-treat analysis using Cox regression models. The population was composed of 19 713 VKA, 8443 dabigatran, and 4651 rivaroxaban new users. All dabigatran- and rivaroxaban-treated patients were matched to 16 014 and 9301 VKA-treated patients, respectively. Among dabigatran-, rivaroxaban-, and their VKA-matched-treated patients, 55 and 122 and 31 and 68 bleeding events and 33 and 58 and 12 and 28 arterial thromboembolic events were observed during follow-up, respectively. After matching, no statistically significant difference in bleeding (hazard ratio, 0.88; 95% confidence interval, 0.64-1.21) or thromboembolic (hazard ratio, 1.10; 95% confidence interval, 0.72-1.69) risk was observed between dabigatran and VKA new users. Bleeding (hazard ratio, 0.98; 95% confidence interval, 0.64-1.51) and ischemic (hazard ratio, 0.93; 95% confidence interval, 0.47-1.85) risks were comparable between rivaroxaban and VKA new users.. In this propensity-matched cohort study, our findings suggest that physicians should exercise caution when initiating either non-VKA oral anticoagulants or VKA in patients with nonvalvular atrial fibrillation.

Topics: Adolescent; Adult; Aged; Anticoagulants; Antithrombins; Arterial Occlusive Diseases; Atrial Fibrillation; Dabigatran; Databases, Factual; Factor Xa Inhibitors; Follow-Up Studies; Hemorrhage; Hospitalization; Humans; Middle Aged; Risk; Rivaroxaban; Thromboembolism; Thrombophilia; Vitamin K; Warfarin; Young Adult

Thrombin generation assay (TGA) is useful as a global functional test for assessing bleeding or thrombotic risk and its modification with therapy. We investigated TGA to assess anticoagulation status compared with the international normalized ratio (INR) system in patients with primary thrombophilia receiving and not undergoing thromboprophylaxis.. We studied 50 patients with at least one thrombotic event and a confirmed diagnosis of inherited thrombophilia. Thrombin generation was measured in platelet-poor plasma by calibrated automated thrombography (CAT).. Patients in optimal anticoagulation (INR: 2.0-3.0) showed an endogenous thrombin potential (ETP) of 14-56% of normal and a peak of 18-55% of normal. A significant inverse relationship between INR and thrombin generation parameters (ETP, peak and velocity index) and a linear correlation for lag time was found in patients treated with vitamin-K antagonists (VKA). Receiver-operating characteristics (ROC) analysis showed that the optimal cutoff for ETP was 1600.2 nM · min (111.6% of normal, with a sensitivity of 96.6% and a specificity of 92.9%) and for the peak was 298.3 nM (112.1% of normal, with a sensitivity of 96.4% and a specificity of 100%). According to this analysis, ETP was able to identify patients with increased thrombotic and hemorrhagic risk, correlating with severe clinical complications.. TGA showed excellent sensitivity and specificity for assessing anticoagulation status in patients with primary thrombophilia receiving VKA, with significant advantages with regard to INR. Clinical data strongly support ETP as a valuable indicator of thrombotic or hemorrhagic risk in patients receiving or not receiving thromboprophylaxis.

Topics: Adult; Anticoagulants; Calibration; Cohort Studies; Female; Healthy Volunteers; Hemorrhage; Heterozygote; Humans; International Normalized Ratio; Male; Middle Aged; Partial Thromboplastin Time; Prothrombin Time; Risk Factors; ROC Curve; Thrombelastography; Thrombin; Thrombophilia; Thrombosis; Vitamin K; Young Adult

The benefits of anti-vitamin K (AVK) drugs have been acknowledged in several indications. Such indications increasing with increasing age, AVK prescriptions also increases with age. At the same time, conditions involving significant bleeding are common in this elderly population. It is thus essential to recognize the determining factors. This study included all patients taking AVK drugs aged 75 years and older who sought emergency care at the Cochin Hospital from January to December 2011 for significant bleeding. These patients were compared with a cohort of patients aged 75 years or older who were taking AVK drugs and who were admitted to the same unit during the same time period for other reasons. The case-control comparison included demographic data, comorbidity factors, multiple medications, emergency measured INR, and CHA2DS2VASC level. The hemorrhagic risk was evaluated by HEMORR2HAGES and HAS-BLED. A total of 34 patients were studied and compared with 70 case-controls. The Charlson comorbidity index was higher in patients than case-controls (P<0.05), with a much higher hemorrhagic risk for scores ≥ 9 (OR=2.5; P<0.05). Multiple medication was also more predominant in patients (P<0.05). The risk of serious hemorrhage was also higher when the hemorrhagic scores were high, especially for HEMORR2HAGES (P<0.0001) and HAS-BLED (P<0.001). The risk of serious hemorrhage in elderly outpatients taking AVK drugs is related to their higher comorbidity and hemorrhagic levels which need to be evaluated before starting or stopping AVK treatment.

Topics: Age Factors; Aged; Aged, 80 and over; Anticoagulants; Atrial Fibrillation; Case-Control Studies; Comorbidity; Female; Hemorrhage; Humans; International Normalized Ratio; Male; Outpatients; Polypharmacy; Risk Factors; Thrombophilia; Vitamin K; Warfarin

For more than a decade, the only treatments available for the prevention of recurrent venous thromboembolism, were vitamin K inhibitors, or low molecular weight heparins (LMWH). Both have been very useful for this purpose; however, with the inconvenience of required frequent laboratory tests and the risk of provoking major hemorrhages. LMWH also carry the risk for immune reactions and the high cost of using it for an extended period of time. With the advent of the new anticoagulants, there is no need for laboratory tests, but there is no way to individualize the dose, or to neutralize their effect. They are also very expensive. Several recent articles have shown that aspirin, as the only treatment for the prevention of recurrent venous thromboembolism, gave good results in comparison to placebo. It has also been found that, after hip replacement surgery, the frequency of thromboembolism was similar in those patients treated with aspirin and those treated with LMWH. These results could open a new path in the search for the ideal treatment for the prevention of recurrent venous thromboembolism.

Topics: Anticoagulants; Antithrombins; Aspirin; Clinical Trials as Topic; Factor Xa Inhibitors; Heparin, Low-Molecular-Weight; Humans; Multicenter Studies as Topic; Pyrazoles; Pyridones; Recurrence; Thromboembolism; Thrombophilia; Venous Thrombosis; Vitamin K

About 40% of patients who receive oral anticoagulation would not start treatment with vitamin K antagonists due to the regular control they require and their interference with the diet and other concomitant medications.. To analyze the preferences of patients with non valvular atrial fibrillation for oral anticoagulants (OAs) for the stroke prevention.. Observational, multicentric study on preferences and maximum willingness to pay based on conjoint analysis: literature review, focus groups and semi-structured interviews with physicians and patients (n = 295) to define the attributes of OAs and their levels. Definition of scenarios that patients ordered according to their preferences. Clusters analysis to identify population groups by their preferences.. Eight scenarios were defined based on five attributes: efficacy, security, a fixed dose, need for coagulation controls and interactions with diet and medication. The most preferred attribute was the smaller number of embolisms in a year (importance: 30.15%) followed by the fixed dose of the OA (25.45%) and the smaller number of intracranial hemorrhage in a year (21.57%). Three clusters population were identified. The maximum amount patients' were willingness to pay for the OA was 66.76 ± 54.64 euros (mean) per month.. Efficacy and a fixed dose are the attributes of OA most valued by non valvular atrial fibrillation patients. There are groups of patients who differ in their preferences. This differences should be taken into account when deciding instauration or change on the OA treatment to ameliorate the accomplishment and prevention in this patients.

Topics: Administration, Oral; Aged; Aged, 80 and over; Anticoagulants; Atrial Fibrillation; Cross-Sectional Studies; Drug Interactions; Factor Xa Inhibitors; Food-Drug Interactions; Humans; Medication Adherence; Middle Aged; Patient Preference; Prescription Fees; Stroke; Thrombophilia; Time Factors; Vitamin K

Topics: Aged; Anticoagulants; Aryl Hydrocarbon Hydroxylases; Atrial Fibrillation; Comorbidity; Cytochrome P-450 CYP2C9; Denmark; Drug Monitoring; Female; Genotype; Humans; International Normalized Ratio; Linear Models; Male; Middle Aged; Outpatient Clinics, Hospital; Phenprocoumon; Prospective Studies; Severity of Illness Index; Stress, Psychological; Surveys and Questionnaires; Thrombophilia; Vitamin K; Warfarin

Vitamin K antagonists (VKAs) are widely used in thromboembolic diseases. We report five cases of necrotic leg ulcers having a particularly severe course and in which withdrawal of VKA treatment alone enabled healing.. Five patients presented with necrotic leg ulcers clinically evocative of necrotic angiodermatitis or vasculitis. Histological features were variable, including inconstantly inflammatory lesions (leukocytoclastic vasculitis) and microthrombosis. None of the patients had laboratory signs of autoimmune disease. Healing occurred in all patients only after withdrawal of VKA therapy (fluindione or acenocoumarol). Associated vascular diseases included superficial venous, distal arterial insufficiency and postphlebitic disease. In three cases, thrombotic factors were observed: hyperhomocysteinaemia or heterozygous Factor V Leiden mutation.. Although the causative role of VKAs is based solely on chronological criteria, this potential side effect deserves publication because of its practical therapeutic consequences. The physiopathological mechanisms accounting for the role of VKAs, including immunoallergic phenomena and, above all, microcirculatory thrombotic processes, are hypothetical and not universally accepted.

Topics: Acenocoumarol; Activated Protein C Resistance; Aged; Aged, 80 and over; Anticoagulants; Diabetic Angiopathies; Factor V; Female; Humans; Hyperhomocysteinemia; Leg Ulcer; Male; Necrosis; Phenindione; Polyarteritis Nodosa; Postoperative Complications; Purpura; Thrombophilia; Varicose Ulcer; Vasculitis, Leukocytoclastic, Cutaneous; Vitamin K

We present the case of a 19-year-old male athlete with protein C deficiency who developed proximal deep venous thrombosis and pulmonary embolism while abusing anabolic-androgenic steroids. Anabolic-androgenic steroids have been reported to have anticoagulatory and profibrinolytic effects in patients with protein C deficiency. Despite these antithrombotic effects, the patient developed repeated venous thromboembolism during treatment with low-molecular-weight heparin. The net effect of anabolic-androgenic steroids on the haemostatic system may change from antithrombotic to prothrombotic in male abusers of anabolic steroids with protein C deficiency.

Topics: Anticoagulants; Blood Coagulation Factors; Dalteparin; Doping in Sports; Enoxaparin; Hematoma, Subdural; Humans; Male; Methandrostenolone; Pleural Effusion; Protein C Deficiency; Pulmonary Embolism; Substance-Related Disorders; Thrombophilia; Thrombophlebitis; Vena Cava Filters; Vitamin K; Young Adult

Warfarin is the most utilized oral anticoagulant for the long term prophylaxes of thrombosis. Its use has been increased as new clinical conditions, capable of leading to thrombosis, have been detected. Due to the special characteristics of warfarin, such as the variability of doses for each individual, the narrow margin between adequate and inadequate doses, interaction with multiple pharmaceutical products, interference of its action by vitamin K present in the diet and the possibility of hemorrhagic complications or thrombotic recurrence, this drug requires a very careful dosage and strict laboratory and clinical monitoring. Despite being in the market for more than de fifty years and its many disadvantages, warfarin has not been substituted for the new oral anticoagulants. In 1999, warfarin was positioned eleventh on the list of the most used medicines in the world.

Topics: Anticoagulants; Drug Interactions; Drug Monitoring; Food-Drug Interactions; Hemorrhage; History, 20th Century; History, 21st Century; Humans; International Normalized Ratio; Mixed Function Oxygenases; Patient Education as Topic; Thrombophilia; Thrombosis; Vitamin K; Vitamin K Epoxide Reductases; Warfarin

Topics: Aged; Aged, 80 and over; Anticoagulants; Atrial Fibrillation; Female; Frail Elderly; Hemorrhage; Humans; Male; Risk; Thrombophilia; Vitamin K; Warfarin

Factor V Leiden (R506Q) mutation is the most commonly observed inherited genetic abnormality related to vein thrombosis. Lebanon has one of the highest frequencies of this mutation in the world with a prevalence of 14.4% in the general population. The aim of this study is to define risk factors including inherited genetic abnormalities among Lebanese patients with lower extremity deep vein thrombosis. We report the clinical outcome of patients with thrombophilia.. From January 1998 to January 2008, 162 patients (61 males and 101 females) were diagnosed with lower extremity deep vein thrombosis. Mean age was 61 years (range: 21 to 95 years).. The most frequent risk factors for vein thrombosis were surgery, advanced age, obesity, and cancer. Twenty-five patients had thrombophilia, 16 patients had factor V Leiden (R506Q) mutation, and seven patients had MTHFR C677T mutation. Ninety-two percent of patients screened for thrombophilia were positive. Screening was requested in young patients (16), patients with recurrent (11), spontaneous (8), and extensive (5) venous thrombosis, familial history (5), pregnancy (4), estroprogestative treatment (3), and air travel (1). Nine patients had one, 11 patients had two, and five had three of these conditions. Follow-up (6 to 120 months) of these 25 patients treated with antivitamin K did not reveal recurrences or complications related to venous thromboembolism.. Factor V Leiden mutation followed by MTHFR mutation are the most commonly observed genetic abnormalities in these series. Defining risk factors and screening for thrombophilia when indicated reduce recurrence rate and complications. Recommendations for thrombophilia screening will be proposed.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Anticoagulants; Asian People; Factor V; Female; Gene Frequency; Genetic Predisposition to Disease; Humans; Incidence; Lebanon; Lower Extremity; Male; Mass Screening; Methylenetetrahydrofolate Reductase (NADPH2); Middle Aged; Mutation; Neoplasms; Obesity; Recurrence; Risk Assessment; Risk Factors; Surgical Procedures, Operative; Thrombophilia; Treatment Outcome; Venous Thrombosis; Vitamin K; Young Adult

Topics: Administration, Oral; Aged; Aged, 80 and over; Anticoagulants; Aspirin; Atrial Fibrillation; Clinical Trials as Topic; Clopidogrel; Contraindications; Drug Therapy, Combination; Hemorrhage; Humans; Intracranial Embolism; Middle Aged; Multicenter Studies as Topic; Platelet Aggregation Inhibitors; Risk Factors; Severity of Illness Index; Thrombophilia; Ticlopidine; Vitamin K; Warfarin

This article discusses the management of venous thromboembolism (VTE) and thrombophilia, as well as the use of antithrombotic agents, during pregnancy and is part of the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that benefits do, or do not, outweigh risks, burden, and costs. Grade 2 recommendations are weaker and imply that the magnitude of the benefits and risks, burden, and costs are less certain. Support for recommendations may come from high-quality, moderate-quality or low-quality studies; labeled, respectively, A, B, and C. Among the key recommendations in this chapter are the following: for pregnant women, in general, we recommend that vitamin K antagonists should be substituted with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) [Grade 1A], except perhaps in women with mechanical heart valves. For pregnant patients, we suggest LMWH over UFH for the prevention and treatment of VTE (Grade 2C). For pregnant women with acute VTE, we recommend that subcutaneous LMWH or UFH should be continued throughout pregnancy (Grade 1B) and suggest that anticoagulants should be continued for at least 6 weeks postpartum (for a total minimum duration of therapy of 6 months) [Grade 2C]. For pregnant patients with a single prior episode of VTE associated with a transient risk factor that is no longer present and no thrombophilia, we recommend clinical surveillance antepartum and anticoagulant prophylaxis postpartum (Grade 1C). For other pregnant women with a history of a single prior episode of VTE who are not receiving long-term anticoagulant therapy, we recommend one of the following, rather than routine care or full-dose anticoagulation: antepartum prophylactic LMWH/UFH or intermediate-dose LMWH/UFH or clinical surveillance throughout pregnancy plus postpartum anticoagulants (Grade 1C). For such patients with a higher risk thrombophilia, in addition to postpartum prophylaxis, we suggest antepartum prophylactic or intermediate-dose LMWH or prophylactic or intermediate-dose UFH, rather than clinical surveillance (Grade 2C). We suggest that pregnant women with multiple episodes of VTE who are not receiving long-term anticoagulants receive antepartum prophylactic, intermediate-dose, or adjusted-dose LMWH or intermediate or adjusted-dose UFH, followed by postpartum anticoagulants (Grade 2C). For those pregnant women with prior VTE who are receiving l

Topics: Antibodies, Antiphospholipid; Antithrombin III Deficiency; Aspirin; Evidence-Based Medicine; Female; Fibrinolytic Agents; Heparin, Low-Molecular-Weight; Humans; Pregnancy; Pregnancy Complications, Cardiovascular; Risk Assessment; Risk Factors; Thrombophilia; Venous Thromboembolism; Vitamin K

Coumarin or anti-vitamin K oral anticoagulants have been used in anticoagulation therapy for more than 50 years. Well-designed studies have demonstrated the effectiveness of these drugs in the primary and secondary prevention of venous thromboembolic disease (VTD). Because of greater life expectancy and the increase in the indications for oral anticoagulation therapy (OAT), more and more patients are receiving this type of treatment. In Spain, approximately 1% of the population receives OAT. The mechanism of action of coumarin anticoagulants is based on inhibition of the interconversion of vitamin K and its 2,3-epoxide (vitamin K epoxide, which modulates gamma-carboxylation of the glutamic acid residues in the N-terminal regions of vitamin-K-dependent factors, namely, II, VII, IX, X, protein C, protein S and protein Z). Due to the lack of gamma-carboxylation, these factors lose their procoagulant activity. Major hemorrhagic complications of OAT in VTD after 3-6 months of treatment, with an INR of 2-3, occur in nearly 2% of patients. The hemorrhagic complications of OAT are related to the intensity of anticoagulation, patient characteristics, the concomitant use of drugs that interfere with hemostasis, and treatment duration. The risk of VTD recurrence after 3-6 months of OAT is high and can be more than 10% in patients with idiopathic thromboembolism or irreversible risk factors such as thrombophilia, cancer and other situations conferring permanent risk. The risk of recurrence is more frequent in men, in patients with thrombophilia especially in antithrombin deficiency, and in patients with cancer, residual venous obstruction, or elevated D dimer.

Topics: Administration, Oral; Age Factors; Aged; Anticoagulants; Coumarins; Drug Interactions; Female; Hemorrhage; Humans; Male; Neoplasms; Randomized Controlled Trials as Topic; Recurrence; Risk Factors; Sex Factors; Spain; Thrombophilia; Time Factors; Venous Thromboembolism; Vitamin K

Topics: Bias; Double-Blind Method; Drug Approval; Endpoint Determination; European Union; Fibrinolytic Agents; Humans; International Normalized Ratio; Patient Selection; Professional Practice; Prospective Studies; Randomized Controlled Trials as Topic; Single-Blind Method; Thrombophilia; Vitamin K

Topics: Anticoagulants; Bias; Case Management; Clinical Trials, Phase III as Topic; Cost-Benefit Analysis; Double-Blind Method; Fibrinolytic Agents; Heparin; Heparin, Low-Molecular-Weight; Humans; Patient Selection; Professional Practice; Prothrombin Time; Quality of Life; Randomized Controlled Trials as Topic; Thrombophilia; Treatment Outcome; Vitamin K

Human prothrombin complex concentrates (PCCs) are used for prevention and treatment of bleeding episodes in patients under warfarin therapy. PCCs contain human factor (F) II, FVII, FIX, FX, protein C and protein S. The concentrations of these coagulation factors contained in PCCs are variable and do not reflect entirely the capacity of these drugs to correct hemostasis. Furthermore, commercially available PCCs do not have exactly the same composition, though they are all labelled and prescribed in units per kg of FIX (10-40 IU of FIX/kg). As the final product generated by PCCs is thrombin, a thrombin generation (TG) test could theoretically be used for monitoring the hemostatic correction.. TG was measured in platelet free plasma in the presence of tissue factor 5 pm and phospholipids 4 microM with a final concentration of PCC of 0-0.1-0.2-0.3-0.4-0.5-0.75-1 IU ml(-1). The activity of vitamin K-dependent coagulation factors (i.e. FII, FVII, FIX, FX, protein C and protein S) were determined for each concentration of two different PCCs available on the French market.. Our results showed that the addition of two different PCCs dose-dependently increased the TG capacity in patients with INR of 2-2.5-3-4 and >7 (n = 15 subjects) that reached the normal values. We also found a significant correlation between endogenous thrombin potential (ETP) and INR (Pearson test, P < 0.0001). The two PCCs improved the TG parameters differently with increasing concentrations. The difference in the correction of TG capacity observed between the two drugs could be explained by a variable increase in FX, FVII and protein C with similar doses. These results strongly suggest that TG assay could be used for monitoring the clinical efficacy of PCC and for optimizing the therapeutic regimen towards a more individualized therapy involving the type of the bleeding complications, the level of inhibition of the coagulation system and the molecule content of the PCC.

Topics: Administration, Oral; Adult; Anticoagulants; Blood Coagulation Factors; Case-Control Studies; Enzyme Precursors; Female; Hemorrhage; Humans; In Vitro Techniques; Male; Middle Aged; Protein C; Thrombin; Thrombophilia; Vitamin K

Topics: Anticoagulants; Drug Administration Schedule; Factor Xa Inhibitors; Female; Fibrin; Fondaparinux; Humans; Middle Aged; Perioperative Care; Phenprocoumon; Polysaccharides; Postoperative Hemorrhage; Surgical Procedures, Operative; Thromboembolism; Thrombophilia; Venous Thrombosis; Vitamin K

Topics: Antibodies, Antiphospholipid; Anticoagulants; Antiphospholipid Syndrome; Dose-Response Relationship, Drug; Humans; International Normalized Ratio; Platelet Aggregation Inhibitors; Prothrombin Time; Thrombophilia; Vitamin K; Warfarin

Topics: Administration, Oral; Anticoagulants; Electric Countershock; Heart Valve Prosthesis; Hemoglobinuria; Heparin, Low-Molecular-Weight; Humans; Medical Audit; Neoplasms; Perioperative Care; Self Administration; Thromboembolism; Thrombophilia; Thrombosis; Vitamin K; Warfarin

LMWHs are the major anticoagulant/antithrombotic treatment given to pregnant women to prevent and treat venous thromboembolism despite the absence of specific clinical trials. An emerging indication, the prevention of adverse pregnancy outcomes, is under investigation. During pregnancy, LMWHs seem to be safe and efficient. Some uncertainties remain about the management of rare potential side effects, particularly in the event of heparin intolerance and with cross-reactivity to danaparoid sodium.

Topics: Abnormalities, Drug-Induced; Anticoagulants; Contraindications; Dermatitis, Allergic Contact; Female; Fibrinolytic Agents; Hemorrhage; Heparin; Humans; Pregnancy; Pregnancy Complications, Hematologic; Thrombocytopenia; Thrombophilia; Venous Thrombosis; Vitamin K

Making decisions about any modality of secondary prophylaxis in patients with venous thromobembolism (VTE) has to balance the risk of bleeding induced by anticoagulants against the benefit of reducing the risk of recurrent disease. It has to be kept in mind that the magnitude of risk is not only defined by the number of events per time period but also by the impact of the event on the fate of the patient. With standard intensity Vitamin K antagonists, the risk of bleeding is more closely related to comorbidities than to other factors, e.g. age. The risk of VTE recurrence differs largely between patient groups. The criterion of presence, or absence of a permanent or transient clinical trigger factor for the actual VTE episode has a greater impact than an abnormal result in thrombophilia testing. The standard period ofsecondary prophylaxis for proximal deep vein thrombosis and for pulmonary embolism is three to six months. The concept of prolonging this period for several months according to the risk of recurrence is seriously challanged by the observation that the prolongation period seems to delay recurrencies rather than truly avoiding them. For this reason, patients who clearly are threatened by recurrent episodes should receive indefinitive secondary prophylaxis. This is the case for cancer patients, patients with the antiphospholipid syndrome, and those who belong to families with severe and symptomatic protein C, protein S, or antithrombin deficiencies. Patients with recurrent VTE, with idiopathic VTE, or with combined thrombophilic conditions may only benefit from indefinitive secondary prophylaxis if the bleeding risk of the anticoagulant regimen under consideration is very low.

Topics: Anticoagulants; Comorbidity; Hemorrhage; Humans; Pulmonary Embolism; Risk Factors; Secondary Prevention; Thrombophilia; Venous Thrombosis; Vitamin K

The status of vitamin K in pregnant women was investigated using the highly sensitive method for des-gamma-carboxyprothrombin (protein induced by vitamin K absence [PIVKA-II]), electrochemiluminescence immunoassay. A gradual elevation of PIVKA-II related to gestational weeks was observed in healthy pregnant women, suggesting that a modest vitamin K deficiency takes place in gestation. Furthermore, throughout gestation the majority of pregnant women exceeded the healthy adult levels in PIVKA-II. Among complicated gestations of preeclampsia, a remarkable elevation of PIVKA-II was observed in severe preeclampsia, in which a high correlation between PIVKA-II level and coagulation parameters, including thrombin-antithrombin (TAT) complexes, was revealed. These data were suggestive that the vitamin K status readily decreased into a deficient status in hypercoagulative conditions. Among other complicated gestations, a moderate elevation of PIVKA-II was demonstrated in hyperemetic conditions, and, if at all, only a slight elevation of PIVKA-II was observed in other maternal diseases. The present study is the first report regarding the changes of PIVKA-II in pregnant women.

Topics: Adult; Biomarkers; Female; Gestational Age; Humans; Immunoassay; Luminescent Measurements; Pre-Eclampsia; Pregnancy; Protein Precursors; Prothrombin; Thrombophilia; Vitamin K

We assessed the predictive value of D-dimer levels in combination with residual venous obstruction (RVO) for recurrent venous thromboembolism (VTE) in a prospective cohort of outpatients after oral anticoagulant therapy (OAT) suspension for a first episode of idiopathic proximal deep vein thrombosis of the lower limbs during a 2-year follow-up. Patients (n=400) were enrolled on the day of OAT suspension when RVO was determined by compression ultrasonography (present in 48.6% of patients). D-dimer (cut-off value: 500 ng/mL) was measured 30+/-10 days afterwards (abnormal in 56.4% of patients). The overall recurrence rate was 16.7% (67/400; 95% confidence intervals - CI -: 13-21 %). The multivariate hazard ratio (HR) for recurrence was 3.32 (95% CI: 1.78-6.75; p<0.0001) for abnormal D-dimer compared to normal D-dimer and 1.2 (95% CI:0.72-2.07; p>0.05) for RVO compared to absent RVO. The recurrence rate was 5.7% (95% CI:2-13%) and 10.4% (95% CI:6-18%), respectively, for normal D-dimer either without or with RVO, 22.9% (95% CI: 14-33%) and 25.9% (95% CI: 18-35%), respectively, for abnormal D-dimer, either without or with RVO. When compared with normal D-dimer without RVO, the multivariate HR for recurrence was similar for abnormal D-dimer either with RVO (4.76 - 95% CI:1.78-12.8) or without RVO (4.3-95%:1.56-11.88). Abnormal D-dimer at one month after OAT withdrawal is an independent risk factor for recurrent VTE, while RVO at the time of OAT withdrawal, either with normal or abnormal D-dimer after one month, does not influence the risk of recurrence.

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Anticoagulants; Biomarkers; Female; Fibrin Fibrinogen Degradation Products; Follow-Up Studies; Humans; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Recurrence; Risk Factors; Thrombophilia; Venous Thrombosis; Vitamin K

Four factor deficiency is variably associated with mild to fatal bleeding. We describe a 3-month-old boy, born of consanguineous parents, who presented with a right subdural haematoma and a clotting screen showing a prothrombin time (PT) > 100 s, an activated partial thromboplastin time (aPTT) > 150 s, a fibrinogen of 0.4 g/l, and fibrinogen degradation products < 1 microg/ml. He was given 300 U of factor IX concentrate (containing factors II and X) and 1 mg of vitamin K intravenously. Forty-five minutes later, clotting tests showed a PT of 24 s, an aPTT of 31 s and a fibrinogen of 2.6 g/l. The patient was found to be deficient in all the vitamin K-dependent factors: factors II, VII, IX and X, protein C and protein S. A 14-base deletion was found in intron 1 (bases 1056-1069) of the gamma-carboxylase gene. The patient and his elder sister were homozygous for this deletion, whereas both parents were heterozygous. The deletion destroys a reverse palindromic sequence (TTGAGGCAA) of the type often associated with cis-acting elements. Our results suggest that this element may be involved in the regulation of gamma-carboxylase expression. Expression studies are being completed so that this region can be definitively ascribed as a cis-acting element involved in gene regulation.

Topics: Blood Coagulation Factors; Blood Coagulation Tests; Carbon-Carbon Ligases; Consanguinity; Factor VII Deficiency; Factor X Deficiency; Female; Hematoma, Subdural; Hemophilia B; Humans; Hypoprothrombinemias; Infant; Introns; Male; Protein C Deficiency; Protein Processing, Post-Translational; Protein S Deficiency; Sequence Deletion; Thrombophilia; Vitamin K

Topics: 4-Hydroxycoumarins; Adult; Anticoagulants; Diagnosis, Differential; Humans; Indenes; Male; Priapism; Thrombophilia; Vitamin K

The endothelial protein C receptor (EPCR) facilitates protein C activation and plays a protective role in the response to Escherichia coli-mediated sepsis in primates. Previously, a soluble form of EPCR (sEPCR) in human plasma was characterized, and several studies indicated that generation of sEPCR is regulated by inflammatory mediators, including thrombin-mediated up-regulation of surface metalloproteolytic activity in vitro. This study addressed the question of whether plasma sEPCR levels reflect changes in thrombin generation in patients undergoing anticoagulant treatment. The sEPCR levels in patients treated with coumarin-type oral anticoagulants were significantly lower than those in healthy asymptomatic adult volunteers (105.3 +/- 70.8 ng/mL [n = 55] versus 165.8 +/- 115.8 ng/mL [n = 200]; P <.0001). A similar decline in plasma sEPCR levels was found in patients treated with unfractionated heparin. In healthy volunteers, sEPCR levels declined to about 100 ng/mL within 3 days after initiation of an 8-day period of warfarin administration and increased within 2 days after its cessation. Plasma sEPCR levels returned to pretreatment values within 1 week, and the changes in plasma sEPCR levels mirrored changes in values for international normalized ratios. A similar decline in sEPCR levels with time was observed in 7 patients beginning treatment with warfarin for a thrombotic disorder. Prothrombin fragment 1 + 2 levels also decreased in volunteers and patients given warfarin. These results show that plasma sEPCR levels decline in response to treatment with anticoagulants whose mechanism of action is known to decrease in vivo thrombin production.

Topics: Adult; Aged; Anticoagulants; Biomarkers; Blood Coagulation Factors; Cardiovascular Diseases; Endothelium, Vascular; Enzyme Activation; Female; France; Genetic Variation; Heparin; Humans; Italy; Male; Metalloendopeptidases; Models, Biological; Peptide Fragments; Protein C; Prothrombin; Receptors, Cell Surface; Solubility; Thrombin; Thrombophilia; Vitamin K; Warfarin

To investigate the relationship among lipids, coagulation and thrombosis in the absence of atherosclerosis, spontaneous or dietary-induced hyperlipidemic (FHL) rats were studied. FHL showed higher levels of coagulation factors VII, IX, X, VIII and XII and a shortening of the occlusion time (OT) of an artificial arterial prosthesis as compared with normolipidemic (FNL) animals. Damage of abdominal aorta of FHL was followed by increased fibrin deposition in the vascular intima as compared to FNL. After 5 months of cholesterol-rich diet FNL showed increased cholesterol, triglycerides and factor II, VII, IX, X, XII levels. A significant shortening of the OT and increased fibrin deposition was also observed. Two-month diet withdrawal restored the initial condition. Warfarin treatment, at a dose decreasing vitamin K-dependent factor to levels found in FNL, prolonged the OT and reduced fibrin deposition, without modifying F XII or changing lipid profile. An increase in the activated form of F VII was observed. In contrast, no difference was found in F VII clearance. High lipid levels favour the process of thrombus formation by increasing the activation of vitamin K-dependent coagulation factors. Low-dose warfarin treatment reverts the prothrombotic effect of hyperlipidemia.

Topics: Administration, Oral; Animals; Anticoagulants; Aorta, Abdominal; Aortic Diseases; Blood Coagulation Factors; Blood Vessel Prosthesis; Cholesterol, Dietary; Diet, Atherogenic; Disease Models, Animal; Enzyme Activation; Factor VII; Hypercholesterolemia; Hyperlipidemias; Hypertriglyceridemia; Postoperative Complications; Rats; Rats, Inbred Strains; Rats, Sprague-Dawley; Thrombophilia; Thrombosis; Vitamin K; Warfarin

Topics: Blood Coagulation; Hemostatics; Heparin Antagonists; Humans; Liver; Thrombophilia; Vitamin K