vitamin-k-semiquinone-radical and Renal-Insufficiency

Traditionally, venous thromboembolism (VTE) resulting from major transient risk factors (e.g., surgery or trauma) or a major persistent risk factor such as cancer, has been defined as being provoked, whereas unprovoked VTE encompasses events without an identifiable cause. These categorizations influence anticoagulant treatment duration; unlike VTE provoked by major transient risk factors, extended anticoagulation beyond 3 months is advised for patients with cancer or unprovoked VTE due to risk persistence after treatment cessation. However, some patients with VTE provoked by minor transient or minor persistent risk factors may also be candidates for extended anticoagulation therapy due to the continuing risk of recurrence. In patients who require extended therapy, vitamin K antagonists (VKAs) are effective but are associated with an increased risk of bleeding and various treatment burdens (e.g., anticoagulation monitoring and dose adjustment). Evaluations of extended VTE treatment with the less-burdensome direct oral anticoagulants such as apixaban, dabigatran, edoxaban, and rivaroxaban show that they are at least as safe and effective as VKAs in a broad range of patients. In addition, apixaban and rivaroxaban offer more than one dosing option, allowing tailoring of treatment to the patient's specific risk factor profile. Analysis of more granular definitions for risk factor groupings has also yielded vital information on the most appropriate strategies for the treatment of patients with specific risk factors, highlighting that extended anticoagulation treatment may benefit those with minor transient and persistent environmental and nonenvironmental risk factors who commonly receive shorter-duration therapy.

Topics: Aged; Anticoagulants; Humans; Patient Selection; Precision Medicine; Pyrazoles; Pyridones; Renal Insufficiency; Risk Factors; Rivaroxaban; Venous Thromboembolism; Vitamin K; Withholding Treatment

Cancer-associated venous thromboembolism (CAT) is a common complication associated with high morbidity and mortality. In accordance with major clinical trials comparing low-molecular-weight heparin (LMWH) with a vitamin K antagonist (VKA), LMWH is currently the standard treatment for CAT, owing to its efficacy for thrombosis recurrence and improved safety profile compared to VKA. Over the past few years, direct oral anticoagulants (DOACs) have emerged as potential alternative therapies to LMWH due to their convenient route of administration and predictable pharmacokinetics, but evidence for their use in CAT is inconclusive, as only a small fraction of the study populations in these trials had CAT. Recently, two large head-to-head trials comparing DOACs to LMWH in CAT patients reported comparable efficacies of DOACs with increased bleeding risk. Occasionally, CAT treatment can be challenging due to the heterogeneity of underlying malignancies and comorbidities. Renal insufficiency and gastrointestinal defects are the main obstacles in anticoagulant selection. Careful choice of treatment candidates and proper anticoagulant strategies are critical for the treatment of CAT; hence, more studies are required to address these challenges.

Topics: Administration, Oral; Anticoagulants; Clinical Trials as Topic; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Renal Insufficiency; Risk Factors; Venous Thromboembolism; 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

Venous thromboembolism (VTE) is one of the leading causes of death in cancer patients, which are known to have a 5- to 7-fold increased risk for VTE. The anticoagulant treatment of VTE in cancer patients is less effective with a three-fold increased risk of VTE recurrence compared to non-cancer patients, and it is less safe with more than double rates of major bleeding. Compared to vitamin-K antagonists (VKA), long-term secondary prevention with low molecular weight heparin (LMWH) has been shown to reduce the risk of recurrent VTE in cancer-associated thrombosis (CAT), and therefore, current international guidelines recommend the use of LMWH over VKA. With increasing age, cancer prevalence and VTE incidence increase while renal function decreases. Anti-cancer treatment may impair renal function additionally. Therefore, renal insufficiency is a frequent challenge in CAT patients, which is associated with a higher risk of both bleeding and recurrent VTE. Both VKA and LMWH may be associated with less efficacy and higher bleeding risk in renal insufficiency. Unfortunately, there is a lack of prospective data on renal insufficiency and CAT. A recent sub-analysis from a large randomized controlled trial shows that the bleeding risk in patients with severe renal insufficiency in CAT is not elevated with the use of LMWH compared to VKA while efficacy is maintained. In addition, LMWH treatment has several practical advantages over VKA, particularly in patients with CAT while they are receiving anti-cancer treatment.

Topics: Anticoagulants; Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Recurrence; Renal Insufficiency; Venous Thromboembolism; Vitamin K; Warfarin

Heparin, whose discovery goes back one hundred years, was first detected as a thromboplastin from liver tissue, and its anticoagulant action was only identified later. The procoagulant action of heparin, which was later characterized as an immunologic reaction by binding to platelet-factor IV, presenting as heparin-induced thrombocytopenia, remains as a side effect. For more than 60 years heparin has been the immediate anticoagulant of choice in many clinical indications. Further development of heparins resulted in the production of low-molecular weight heparins and Fondaparinux, which substituted heparin for many indications and has received many more new indications, including administration for non-anticoagulant purposes. This development is still ongoing and has resulted in more than 300 registered clinical trials at the end of 2015. All types of heparins are still investigated in patients with impairment of renal function to improve the safety of treatment. New therapeutic strategies for the prevention and treatment of thromboembolism, as well as of the non-anticoagulant actions of natural and modified types of heparins, are studied intensively. The clinical study designs include treatment with vitamin-K and non-vitamin K oral anticoagulants. Consequently, heparins, low-molecular weight heparins and Fondaparinux play an important role in the human health care system.

Topics: Anticoagulants; Clinical Trials as Topic; Drug Design; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Humans; Polysaccharides; Renal Insufficiency; Thromboembolism; Vitamin K

Atrial fibrillation (AF) is a common cardiac rhythm disturbance and is associated with a 5-fold increased risk of stroke. The most important risk factors for stroke in patients with AF are previous stroke and age ≥ 75 years. Canadian guidelines recommend anticoagulant therapy for patients with AF who are older than the age of 65 years, but the elderly often remain undertreated, primarily because of concerns regarding bleeding. Non-vitamin K oral anticoagulants appear to be safer, at least as efficacious, and more convenient than warfarin, and are a cost-effective alternative for elderly patients with AF. We review the evidence for the use of antithrombotic agents for stroke prevention in elderly patients (age ≥ 75 years) with nonvalvular AF.

Topics: Accidental Falls; Aged; Anticoagulants; Atrial Fibrillation; Cognitive Dysfunction; Coronary Artery Disease; Fibrinolytic Agents; Hemorrhage; Humans; Platelet Aggregation Inhibitors; Polypharmacy; Renal Insufficiency; Risk Assessment; Stroke; Vitamin K

To investigate the relative effect of warfarin versus non-vitamin K oral anticoagulants (NOACs) in thrombotic and bleeding outcomes in subgroups of atrial fibrillation (AF) patients with varying degrees of renal dysfunction.. Systemic review and meta-regression analyses on NOACs versus warfarin, supplemented with indirect comparisons were conducted. The eligibility criteria for inclusion were randomised controlled trials comparing NOACs against warfarin for stroke prevention in AF patients. Outcomes of interest were stroke or systemic embolism (SE) and major bleeding.. Five studies comprising 72,845 AF patients randomised to either a NOAC or warfarin were included in the meta-regression analysis. A shift in strata from no renal impairment to renal impairment resulted in a non-significant impact on bleeding and stroke/SE, indicating similar safety and efficacy, despite renal function status. Apixaban was associated with less major bleeding compared to dabigatran and rivaroxaban but not edoxaban in patients with moderate renal impairment. For efficacy outcomes, only dabigatran 150 mg was statistically significantly favoured compared to edoxaban 30 mg. For efficacy outcomes in mild renal impairment, both dabigatran 150 mg and rivaroxaban 10 mg (J-ROCKET) were statistically significantly favoured against edoxaban 30 mg.. Non-vitamin K oral anticoagulants had similar efficacy and safety compared to warfarin across different levels of renal function. Indirect comparisons suggest that apixaban and edoxaban were associated with a better safety profile in patients with moderate renal impairment. However, caution is warranted when interpreting indirect comparisons of drugs investigated in different trials. Prescribers should fit the most appropriate NOAC to the AF patient characteristics (and vice versa) to individualise effective stroke prevention.

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Clinical Trials as Topic; Hemorrhage; Humans; Randomized Controlled Trials as Topic; Renal Insufficiency; Stroke; Treatment Outcome; Vitamin K; Warfarin

Vitamin K antagonists (VKA)-related nephropathy is a novel entity characterized by acute kidney injury related to International Normalized Ratio supratherapeutic levels. Non-vitamin K antagonists oral anticoagulants (NOACs) have a predictable dose-response relationship and an improved safety profile. We hypothesized that these drugs do not have an increased risk of incident renal failure, which may be detrimental for the use of NOACs.. Systematic review and meta-analysis of phase III randomized controlled trials (RCTs). Trials were searched through Medline, Cochrane Library and public assessment reports in August 2014. Primary outcome was renal failure. NOACs were evaluated against any comparator. Random-effects meta-analysis was performed by default, and pooled estimates were expressed as Risk Ratio (RR) and 95%CI. Heterogeneity was evaluated with I(2) test.. Ten RCTs fulfilled inclusion criteria (one apixaban RCT, three dabigatran RCTs, and six rivaroxaban RCTs), enrolling 75 100 patients. Overall NOACs did not increase the risk of renal failure with an RR 0.96, 95%CI 0.88-1.05 compared with VKA or Low-molecular weight heparin (LMWH), without significant statistical heterogeneity (I(2)  = 3.5%). Compared with VKA, NOACs did not increase the risk of renal failure (RR 0.96, 95%CI 0.87-1.07; I(2)  = 17.8%; six RCTs). Rivaroxaban did not show differences in the incidence of renal failure compared with LMWH (RR 1.20, 95%CI 0.37-3.94; four trials), but there was an increased risk of creatinine elevation RR 1.25, 95%CI 1.08-1.45; I(2)  = 0%.. NOACs had a similar risk of renal failure compared with VKA/LMWH in phase III RCTs. Post-marketing surveillance should be warranted.

Topics: Administration, Oral; Anticoagulants; Clinical Trials, Phase III as Topic; Humans; International Normalized Ratio; Randomized Controlled Trials as Topic; Renal Insufficiency; Risk Assessment; Vitamin K

The major practical advantage of the direct oral anticoagulants (DOACs), comprising the thrombin inhibitor dabigatran and the factor Xa inhibitors apixaban, edoxaban, and rivaroxaban, over vitamin K antagonists is their fixed dosing without the need for laboratory monitoring. With the recent, rapid introduction of the DOACs for the treatment of acute venous thromboembolism (VTE), clinicians are now faced with various questions regarding the efficacy and safety of these compounds overall and in specific high-risk populations. The collective evidence from 6 large clinical trials involving 27,000 patients has demonstrated that DOACs are as effective as vitamin K antagonists (VKA) in preventing recurrent VTE while being associated with a significantly lower risk of major bleeding. These findings are consistent in subgroups of patients with pulmonary embolism, the elderly, and those patients with a high body weight or moderate renal insufficiency, making these agents suitable for a broad spectrum of patients with VTE. DOACs are also an attractive treatment option in patients with VTE and concomitant cancer, thrombotic antiphospholipid syndrome, or heparin-induced thrombocytopenia, but the currently available clinical data is insufficient to make evidence-based recommendations on the use of DOACs in these settings. Several studies evaluating the efficacy and safety of DOACs in these high-risk populations are underway.

Topics: Administration, Oral; Anticoagulants; Antiphospholipid Syndrome; Clinical Trials as Topic; Factor Xa Inhibitors; Hemorrhage; Humans; Neoplasms; Pulmonary Embolism; Recurrence; Renal Insufficiency; Risk; Thrombin; Thrombocytopenia; Thrombosis; Treatment Outcome; Venous Thromboembolism; Venous Thrombosis; Vitamin K

Regarding anticoagulant therapies there has been a remarkable shift in recent years. The objective of this brief overview is to provide relevant information and guidelines on the advantages and disadvantages of novel anticoagulants addressing specifically the surgical disciplines. Hitherto, conventional anticoagulant therapy in patients with a high thrombosis risk was largely limited to heparins and vitamin-K antagonists (VKA). Their modes of action, the difficulties in managing VKAs (e.g., bridging therapy) and the risk of HIT (heparin-induced thrombocytopenia) associated with heparins are briefly discussed. Novel anticoagulants supposedly eliminate these obstacles. Fondaparinux (Arixtra®) is a fully synthetic pentasaccharide which acts like a heparin but has an increased half life. Fondaparinux has a diminished risk of HIT. However, no specific antidote is currently available for Fondaparinux. The novel oral anticoagulants (NOAC) dabigatran etexilat (Pradaxa®), rivaroxaban (Xarelto®) and apixaban (Eliquis®), also known as "direct" anticoagulants, act independently from antithrombin by inhibiting thrombin, as in the case of dabigatran, or by inhibiting factor Xa, as in the case of rivaroxaban and apixaban. It is assumed that they are suitable for long-term use and do not require laboratory monitoring. Nevertheless, clinical experience is very limited and caution rather than quick conclusions is necessary. Two major drawbacks are on the one hand the risk of drug accumulation in kidney and/or liver disease and, on the other hand, the lack of specific antidotes. In addition, interactions with other medication may have unexpected effects on serum drug levels. Therefore, the analysis of drug levels in the plasma may become necessary in subgroups of patients.. Studies establishing clear recommendations for the desirable and measurable reference range are needed. Similarly, evidence-based recommendations regarding perioperative prevention of thrombosis are required ("bridging": yes or no?). Irrespective of these issues, the authors predict a further expansion of the use of NOACs.

Topics: Administration, Oral; Anticoagulants; Benzimidazoles; Blood Coagulation Tests; Dabigatran; Drug Interactions; Factor Xa Inhibitors; Fondaparinux; Heparin; Humans; International Normalized Ratio; Liver Failure; Metabolic Clearance Rate; Morpholines; Perioperative Care; Polysaccharides; Pyrazoles; Pyridines; Pyridones; Renal Insufficiency; Rivaroxaban; Thiophenes; Thrombocytopenia; Thrombosis; Vitamin K

The use of new oral anticoagulants (NOACs) in patients with impaired renal function has raised major concerns, in particular the possibility of an increased risk of bleeding due to accumulation. The aims of this work were to assess the safety of NOACs in patients with renal failure and describe the relationship between clinical events and drug renal excretion magnitude.. All phase III trials comparing NOACs with vitamin K antagonists (VKAs) in patients with estimated glomerular filtration (eGFR) rate < 50 mL min(-1) were eligible. The main safety and efficacy outcomes were major bleeding and thrombosis. A meta-regression was performed to estimate the correlation between the treatment effect estimate and the percentage of renal excretion.. Nine studies (12 272 patients) were included. A significantly greater relative reduction in major bleeding was seen for NOACs with renal excretion <50% (RR, 0.61; CI, 0.51-0.74) than for those with high renal excretion (RR, 0.96; CI, 0.85-1.07) (interaction test, P < 0.0001). A linear relationship between the relative risk of major bleeding and the magnitude of renal excretion was found by meta-regression (R(2)  = 0.66, P = 0.03). For thrombosis, a greater treatment effect of NOA vs. INR-adjusted VKA was observed in patients with eGFR < 50 mL min(-1) (RR 0.78, CI 0.67-0.92), but no correlation between treatment effect and renal excretion was found.. New oral anticoagulants were at least as effective as VKAs, with reduced risks of major bleeding and thrombosis in patients with eGFR < 50 mL min(-1) . The renal excretion of these new drugs seemed to modify the safety profile, contrary to the efficacy.

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Clinical Trials, Phase III as Topic; Glomerular Filtration Rate; Hemorrhage; Humans; Renal Insufficiency; Thrombosis; Treatment Outcome; Venous Thromboembolism; Vitamin K; Warfarin

Novel oral anticoagulants (NOACs) have been developed as alternatives for vitamin K antagonists (VKAs) for the prevention of thromboembolic events in patients with a variety of medical conditions. In this review, we summarize the current data on NOACs safety and efficacy compared to VKAs and in specific patients' groups including heart valve replacement, venous thromboembolism, advanced renal failure and the elderly.

Topics: Administration, Oral; Anticoagulants; Chemistry, Pharmaceutical; Humans; Pulmonary Embolism; Renal Insufficiency; Thromboembolism; Vitamin K

The majority of patients with nonvalvular atrial fibrillation (AF) will require anticoagulation therapy for reducing the risk of stroke, the most devastating complication of AF. Although traditionally vitamin K antagonists have been used for this purpose, they have important limitations that interfere with their use in clinical practice. Different clinical trials have shown the benefits of new oral anticoagulants over warfarin, but patients included in the ROCKET-AF trial were found to be at a higher risk of AF-related complications. Moreover, rivaroxaban has been proven to be effective and safe in patients with AF and moderate renal dysfunction as well as in those with ischemic heart disease. Rivaroxaban is taken only once daily; this may improve medication adherence and, secondarily, it provides a higher protection and reduction in the risk of stroke. This article provides an extensive review of the available evidence about rivaroxaban, with a special focus on nonvalvular AF.

Topics: Anticoagulants; Antithrombins; Atrial Fibrillation; Humans; Ischemic Attack, Transient; Medication Adherence; Morpholines; Renal Insufficiency; Rivaroxaban; Severity of Illness Index; Stroke; Thiophenes; Thromboembolism; Vitamin K; Warfarin

Decision making with regard to thromboprophylaxis should be based upon the absolute risks of stroke/thromboembolism and bleeding and the net clinical benefit for a given patient. As a consequence, a crucial part of atrial fibrillation (AF) management requires the appropriate use of thromboprophylaxis, and the assessment of stroke as well as bleeding risk can help inform management decisions by clinicians. The objective of this review article is to provide an overview of stroke and bleeding risk assessment in AF. There would be particular emphasis on when, how, and why to use these risk stratification schemes, with a specific focus on the CHADS2 [congestive heart failure, hypertension, age, diabetes, stroke (doubled)], CHA2DS2-VASc [congestive heart failure or left ventricular dysfunction, hypertension, age ≥ 75 (doubled), diabetes, stroke (doubled)-vascular disease, age 65-74 and sex category (female)], and HAS-BLED [hypertension (i.e. uncontrolled blood pressure), abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR (if on warfarin), elderly (e.g. age >65, frail condition), drugs (e.g. aspirin, NSAIDs)/alcohol concomitantly] risk scores.

Topics: Aged; Anticoagulants; Aspirin; Atrial Fibrillation; Biomarkers; Echocardiography; Female; Fibrinolytic Agents; Hemorrhage; Humans; Male; Practice Guidelines as Topic; Renal Insufficiency; Risk Assessment; Risk Factors; Stroke; Thromboembolism; Vitamin K

Current evidence-based guidelines provide recommendations for prophylaxis and treatment of venous thromboembolism (VTE) in a variety of surgical patients.. A systematic Ovid Medline search (from 1950 to the present) was conducted for relevant articles using the following search terms: "venous thromboembolism," "thrombophlebitis," "thromboembolism," "pulmonary embolism," "heparin," "low-molecular-weight heparin," "postoperative complications," and "anticoagulants.". Pharmacologic and mechanical approaches are available for VTE prophylaxis, including low-dose unfractionated heparin, low-molecular-weight heparin, vitamin K antagonists, fondaparinux, intermittent pneumatic compression devices, and graduated compression stockings. Permanent inferior vena cava filters are not recommended for primary VTE prophylaxis, although they do have a role in the prevention of pulmonary embolism in patients with recent VTE who cannot have surgery delayed. Retrievable inferior vena cava filters are under investigation for primary VTE prophylaxis in trauma patients. New anticoagulants that inhibit factor Xa and thrombin will soon be available for the prevention and treatment of VTE in surgical patients.

Topics: Anticoagulants; Contraindications; Heparin; Humans; Intermittent Pneumatic Compression Devices; Patient Care Team; Postoperative Complications; Practice Guidelines as Topic; Renal Insufficiency; Risk Factors; Stockings, Compression; Surgical Procedures, Operative; Venous Thromboembolism; Vitamin K

Topics: Animals; Anticoagulants; Calcinosis; Chronic Disease; Humans; Renal Dialysis; Renal Insufficiency; Vascular Diseases; Vitamin K; Vitamin K Deficiency; Warfarin

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

The optimal management of major bleeding in patients receiving vitamin K antagonists (VKA) for venous thromboembolism (VTE) is unclear.. We used the RIETE (Registro Informatizado Enfermedad TromboEmbólica) registry to assess the management and 30-day outcomes after major bleeding in patients receiving VKA for VTE.. From January 2013 to December 2017, 267 of 18,416 patients (1.4%) receiving long-term VKA for VTE had a major bleeding (in the gastrointestinal tract 78, intracranial 72, hematoma 50, genitourinary 20, other 47). Overall, 151 patients (57%) received blood transfusion; 110 (41%) vitamin K; 37 (14%) fresh frozen plasma; 29 (11%) pro-haemostatic agents and 20 (7.5%) a vena cava filter. During the first 30 days, 59 patients (22%) died (41 died of bleeding) and 13 (4.9%) had a thrombosis. On multivariable analysis, patients with intracranial bleeding (hazard ratio [HR]: 4.58; 95%CI: 2.40-8.72) and those with renal insufficiency at baseline (HR: 2.73; 95%CI: 1.45-5.15) had an increased mortality risk, whereas those receiving vitamin K had a lower risk (HR: 0.47; 0.24-0.92). On the other hand, patients receiving fresh frozen plasma were at increased risk for thrombotic events (HR: 4.22; 95%CI: 1.25-14.3).. Major bleeding in VTE patients receiving VKA carries a high mortality rate. Intracranial bleeding and renal insufficiency increased the risk. Fresh frozen plasma seems to increase this risk for recurrent VTE.

Topics: Aged; Aged, 80 and over; Anticoagulants; Blood Transfusion; Female; Hemorrhage; Hemostatics; Humans; Male; Middle Aged; Renal Insufficiency; Retrospective Studies; Treatment Outcome; Venous Thromboembolism; Vitamin K

In a randomized trial (ie, Comparison of Low-Molecular-Weight Heparin versus Oral Anticoagulant Therapy for the Prevention of Recurrent Venous Thromboembolism in Patients with Cancer [CLOT]) that evaluated secondary prophylaxis of recurrent venous thromboembolism (VTE) in patients with cancer, dalteparin reduced the relative risk by 52% compared to oral vitamin K antagonists (VKAs; hazard ratio = 0.48, P = .002). A recent subgroup analysis in patients with moderate to severe renal impairment also revealed lower absolute VTE rates with dalteparin (3% vs 17%; P = .011). To measure the economic value of dalteparin in these populations, a pharmacoeconomic analysis was conducted from the Dutch health-care system perspective.. Resource utilization data contained within the CLOT trial database were extracted and converted into direct cost estimates. Univariate analysis was then conducted to compare the total cost of therapy between patients randomized to dalteparin or VKA therapy. Health state utilities were then measured in 24 members of the general public using the time trade-off technique.. When all of the cost components were combined for the entire population (n = 676), the dalteparin group had significantly higher overall costs than the VKA control group (dalteparin = €2375 vs VKA = €1724; P < .001). However, dalteparin was associated with a gain of 0.14 (95% confidence interval [CI]: 0.10-0.18) quality-adjusted life years (QALYs) over VKA. When the incremental cost was combined with the utility gain, dalteparin had a cost of €4,697 (95% CI: €3824-€4951) per QALY gained.. Secondary prophylaxis with dalteparin is a cost-effective alternative to VKA for the prevention of recurrent VTE in patients with cancer.

Topics: Adult; Aged; Aged, 80 and over; Anticoagulants; Cost-Benefit Analysis; Dalteparin; Female; Heparin, Low-Molecular-Weight; Humans; Male; Middle Aged; Recurrence; Renal Insufficiency; Venous Thromboembolism; Vitamin K; Young Adult

Hyperphosphataemia is strongly associated with cardiovascular disease and mortality. Recently, phosphate binders (PBs), which are used to bind intestinal phosphate, have been shown to bind vitamin K, thereby potentially aggravating vitamin K deficiency. This vitamin K binding by PBs may offset the beneficial effects of phosphate reduction in reducing vascular calcification (VC). Here we assessed whether combining PBs with vitamin K2 supplementation inhibits VC.. We performed 3/4 nephrectomy in rats, after which warfarin was given for 3 weeks to induce vitamin K deficiency. Next, animals were fed a high phosphate diet in the presence of low or high vitamin K2 and were randomized to either control or one of four different PBs for 8 weeks. The primary outcome was the amount of thoracic and abdominal aorta VC measured by high-resolution micro-computed tomography (µCT). Vitamin K status was measured by plasma MK7 levels and immunohistochemically analysed in vasculature using uncarboxylated matrix Gla protein (ucMGP) specific antibodies.. The combination of a high vitamin K2 diet and PB treatment significantly reduced VC as measured by µCT for both the thoracic (P = 0.026) and abdominal aorta (P = 0.023), compared with MK7 or PB treatment alone. UcMGP stain was significantly more present in the low vitamin K2-treated groups in both the thoracic (P < 0.01) and abdominal aorta (P < 0.01) as compared with high vitamin K2-treated groups. Moreover, a high vitamin K diet and PBs led to reduced vascular oxidative stress.. In an animal model of kidney failure with vitamin K deficiency, neither PB therapy nor vitamin K2 supplementation alone prevented VC. However, the combination of high vitamin K2 with PB treatment significantly attenuated VC.

Topics: Animals; Calcium-Binding Proteins; Extracellular Matrix Proteins; Female; Male; Models, Animal; Phosphates; Rats; Renal Dialysis; Renal Insufficiency; Vascular Calcification; Vitamin K; Vitamin K 1; Vitamin K 2; Vitamin K Deficiency; X-Ray Microtomography

Dose reduction of non-vitamin K antagonist oral anticoagulants (NOACs) is indicated in patients with atrial fibrillation (AF) with renal impairment. Failure to reduce the dose in patients with severe kidney disease may increase bleeding risk, whereas dose reductions without a firm indication may decrease the effectiveness of stroke prevention.. The goal of this study was to investigate NOAC dosing patterns and associated outcomes, i.e., stroke (ischemic stroke and systemic embolism) and major bleeding in patients treated in routine clinical practice.. Using a large U.S. administrative database, 14,865 patients with AF were identified who initiated apixaban, dabigatran, or rivaroxaban between October 1, 2010, and September 30, 2015. We examined use of a standard dose in patients with a renal indication for dose reduction (potential overdosing) and use of a reduced dose when the renal indication is not present (potential underdosing). Cox proportional hazards regression was performed in propensity score-matched cohorts to investigate the outcomes.. Among the 1,473 patients with a renal indication for dose reduction, 43.0% were potentially overdosed, which was associated with a higher risk of major bleeding (hazard ratio: 2.19; 95% confidence interval: 1.07 to 4.46) but no statistically significant difference in stroke (3 NOACs pooled). Among the 13,392 patients with no renal indication for dose reduction, 13.3% were potentially underdosed. This underdosing was associated with a higher risk of stroke (hazard ratio: 4.87; 95% confidence interval: 1.30 to 18.26) but no statistically significant difference in major bleeding in apixaban-treated patients. There were no statistically significant relationships in dabigatran- or rivaroxaban-treated patients without a renal indication.. In routine clinical practice, prescribed NOAC doses are often inconsistent with drug labeling. These prescribing patterns may be associated with worse safety with no benefit in effectiveness in patients with severe kidney disease and worse effectiveness with no benefit in safety in apixaban-treated patients with normal or mildly impaired renal function.

Topics: Administration, Oral; Adolescent; Adult; Aged; Aged, 80 and over; Antithrombins; Atrial Fibrillation; Dabigatran; Dose-Response Relationship, Drug; Factor Xa Inhibitors; Female; Follow-Up Studies; Hemorrhage; Humans; Incidence; Male; Middle Aged; Pyrazoles; Pyridones; Renal Insufficiency; Retrospective Studies; Rivaroxaban; Stroke; Time Factors; Treatment Outcome; United States; Vitamin K; Young Adult

Topics: Administration, Oral; Anticoagulants; Blood Coagulation Factors; Clinical Trials as Topic; Contraindications; Humans; Liver Diseases; Practice Guidelines as Topic; Renal Insufficiency; Thromboembolism; Vitamin K

In contrast to heparins and oral anticoagulants, anti IIa inhibitors (thrombin inhibitors) are able to directly inhibit the protease activity of thrombin and can thereby precisely control the blood coagulation process. Direct thrombin inhibitors are either biosimilars (r-hirudin) or synthetically produced substances (bivalirudin, argatroban, dabigatran). In 1997 r-hirudin was introduced into clinical practice, however due to its narrow therapeutic range and the necessity of drug monitoring it has not gained widespread clinical use by now. Since 2004 and 2005 the synthetic thrombin inhibitors bivalirudin and argatroban, respectively, are available. With dabigatran the first oral synthetic thrombin inhibitor followed in 2008. These four drugs can inhibit even clot bound thrombin and show low plasma protein binding. They differ in respect to route and duration of application as well as elimination from the body, thereby offering a precise inhibition of blood coagulation adjusted to the individual case and without danger of HIT II. These advantages shall be used and advanced by the development of further direct thrombin inhibitors.

Topics: Aged; Anticoagulants; Biotransformation; Coumarins; Female; Hemostasis; Heparin; Humans; International Normalized Ratio; Male; Middle Aged; Pharmacogenetics; Renal Insufficiency; Vitamin K; Warfarin

Initial treatment of venous thromboembolic events is currently based on antithrombotics. This treatment is validated and identical for deep vein thrombosis (DVT) and pulmonary embolism. For distal DVT, this treatment has still to be validated. This reference therapeutic strategy is firstly parenteral and based on low-molecular-weight heparins (LMWH) or fondaparinux, subcutaneously prescribed at fixed dosage based on body weight without any systematic dose adjustment on hemostasis tests. Unfractionated heparin is steel the reference treatment in case of severe renal insufficiency. This parenteral treatment has to be relieved by vitamin K antagonists (VKA). VKA has to be co-administrated for at least 3 days, without any loading dose and can be early initiated. VKA dose needs to be adjusted in order to maintain INR between 2 and 3. However, in case of cancer, LMWH have to be carried on for 6 months. A part this antithrombotic treatment, thrombolytics are recommended in case of massive PE and vena cava filter should be used in case of recurrence despite adequate antithrombotic treatment or in case of contraindication to antithrombotic.

Topics: Anticoagulants; Antifibrinolytic Agents; Factor X; Fibrinolytic Agents; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Humans; Injections, Intravenous; Injections, Subcutaneous; International Normalized Ratio; Polysaccharides; Pulmonary Embolism; Renal Insufficiency; Thromboembolism; Vena Cava Filters; Venous Thrombosis; Vitamin K

Topics: Anticoagulants; Contraindications; Creatinine; Drug Interactions; Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Platelet Count; Renal Insufficiency; Thrombocytopenia; Venous Thrombosis; Vitamin K