Search results for "vitamin K"
showing 10 items of 108 documents
Association between antithrombotic treatment and outcomes at 1-year follow-up in patients with atrial fibrillation: the EORP-AF General Long-Term Reg…
2019
Aims In recent years, stroke prevention in patients with atrial fibrillation (AF) has radically changed, with increasing use of non-vitamin K antagonist oral anticoagulants (NOACs). Contemporary European data on AF thromboprophylaxis are needed. Methods and results We report 1-year follow-up data from the EURObservational Research Programme in Atrial Fibrillation (EORP-AF) General Long-Term Registry. Outcomes were assessed according to antithrombotic therapy. At 1-year follow-up, 9663 (88.0%) patients had available data for analysis: 586 (6.1%) were not treated with any antithrombotic; 681 (7.0%) with antiplatelets only; 4066 (42.1%) with vitamin K antagonist (VKA) only; 3167 (32.8%) with …
Incidence of thromboembolic complications in patients with mechanical heart valves with a subtherapeutic international normalized ratio.
2008
Objective Subtherapeutic international normalized ratios are frequently encountered in clinical practice, and patients with mechanical heart valves with inadequate anticoagulation may be exposed to an increased risk of thromboembolic events. There are no data on thromboembolic event risk for these patients. Methods We assessed the current practice patterns in the management of patients with mechanical heart valves with subtherapeutic international normalized ratios and assessed the risk of thromboembolic complications in this setting. The charts of patients with mechanical heart valves followed up in two anticoagulation clinics were reviewed. Patients with a history of stable, therapeutic a…
Vitamin K antagonists' use and fracture risk: results from a systematic review and meta‐analysis
2015
Background: Although vitamin K antagonists (VKAs) lower serum values of bone deposition markers, the link with osteoporosis and fractures remains controversial. Objectives: To assess whether the use of VKAs is associated with an increased prevalence and/or incidence of osteoporosis, fractures, or lower bone mineral density (BMD) values. Methods: We conducted a systematic PubMed and EMBASE literature search until August 31, 2014, and a meta-analysis of cross-sectional and longitudinal studies investigating fractures and BMD, comparing patients treated with VKAs and healthy controls (HCs) or with patients with medical illness (medical controls, MCs). Standardized mean differences ± 95% and co…
Natural history of mesenteric venous thrombosis in patients treated with vitamin K antagonists: a multi-centre, retrospective cohort study.
2009
summaryKnowledge on the natural history of mesenteric vein thrombosis (MVT) and of the efficacy and safety of long-term oral anticoagulant therapy (OAT) in this setting is based on small uncontrolled series of patients with a limited follow-up. It was the aim of the study to assess the natural history of MVT in a cohort of patients treated with OAT. The charts of all MVT patients currently attending or who have attended four anticoagulation clinics were reviewed. Information on risk factors, treatment, recurrence, major bleeding and mortality was collected. Seventyseven patients (mean age 49.2 years; 45 males) were included with a median follow-up of 36 months (range 2–204 months). Forty-si…
Patients requiring interruption of long-term oral anticoagulant therapy: the use of fixed sub-therapeutic doses of low-molecular weight heparin.
2009
Introduction: We tested the efficacy and safety of fixed doses of Low-Molecular Weight Heparin (LMWH) in patients requiring interruption of Vitamin-k Antagonist (VKA) because of invasive procedures Methodology: Pre-operatively, patients discontinued VKA 5 +/- 1days; in those at low-risk for thrombosis, LMWH was given at a prophylactic dosage of 3.800 U.I. (nadroparin) or 4.000 U.I. (enoxaparin) anti-FXa once daily the night before the procedure. In patients at high-risk for thrombosis, LMWH was started early after VKA cessation and given at fixed sub-therapeutic doses (3.800 or 4.000 UI anti-FXa twice daily) until surgery. Post-operatively, LMWH was reinitiated 12 hours after procedure whil…
Residual vein thrombosis for assessing duration of anticoagulation after unprovoked deep vein thrombosis of the lower limbs: the extended DACUS study.
2011
Abstract The safest duration of anticoagulation after idiopathic deep vein thrombosis (DVT) is unknown. We conducted a prospective study to assess the optimal duration of vitamin K antagonist (VKA) therapy considering the risk of recurrence of thrombosis according to residual vein thrombosis (RVT). Patients with a first unprovoked DVT were evaluated for the presence of RVT after 3 months of VKA administration; those without RVT suspended VKA, while those with RVT continued oral anticoagulation for up to 2 years. Recurrent thrombosis and/or bleeding events were recorded during treatment (RVT group) and 1 year after VKA withdrawal (both groups). Among 409 patients evaluated for unprovoked DVT…
Is it necessary to alter anticoagulation therapy for tooth extraction in patients taking direct oral anticoagulants?
2017
Background The number of patients using direct oral anticoagulants (DOACs) instead of vitamin K antagonists (VKA) is increasing and there is limited data on the safety of tooth extractions in patients taking DOACs. The aim of this study was to compare the amount of bleeding (AOB) and postoperative complications after tooth extractions between patients taking VKAs and patients taking DOACs without altering the anticoaguation therapy. Material and Methods The study consisted of four groups: Direct thrombin inhibitor group, factor Xa inhibitor group, warfarin group and a control group. A single tooth was extracted in each patient and routine coagulation test values were recorded prior to extra…
Clinical Problem Solving and Using New Paths in the Laboratory: Learning from Case Studies.
2020
AbstractThree selected casuistic studies of individual patient problems from my long-standing professional experience are presented. I intend to highlight the potential contribution of case studies, including new approaches of laboratory investigation, for the advancement of pathophysiological knowledge and would encourage to “rehabilitate” the low academic profile generally attributed to “case reports.”
VITAMIN K-INDUCED MODIFICATION OF COAGULATION PHENOTYPE IN VKORC1 HOMOZYGOUS DEFICIENCY
2008
Summary. Background: Combined vitamin K-dependent clotting factor (VKCF) deficiency type 2 (VKCFD2) is a rare bleeding disorder caused by mutated vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) gene. Methods and results: An Italian patient with moderate to severe bleeding tendency was genotyped, and found to be homozygous for the unique VKORC1 mutation (Arg98Trp) so far detected in VKCFD2. The activity levels of VKCFs were differentially reduced, and inversely related to the previously estimated affinity of procoagulant factor propeptides for the γ-carboxylase. The normal (factor IX) or reduced antigen levels (other VKCFs) produced a gradient in specific activities. Vitamin K su…
Intestinal Scavenger Receptors Are Involved in Vitamin K 1 Absorption
2014
International audience; Vitamin K-1 (phylloquinone) intestinal absorption is thought to be mediated by a carrier protein that still remains to be identified. Apical transport of vitamin K-1 was examined using Caco-2 TC-7 cell monolayers as a model of human intestinal epithelium and in transfected HEK cells. Phylloquinone uptake was then measured ex vivo using mouse intestinal explants. Finally, vitamin K-1 absorption was compared between wild-type mice and mice overexpressing scavenger receptor class B type I (SR-BI) in the intestine and mice deficient in cluster determinant 36 (CD36). Phylloquinone uptake by Caco-2 cells was saturable and was significantly impaired by co-incubation with al…