vitamin-k-1 and Thrombosis

Controversy exists whether low-dose vitamin K supplementation can improve anticoagulation control in patients with unstable anticoagulation under warfarin. In a single- centre randomized, double-blind, placebo-controlled study, we evaluated the effectiveness of 200 μg/day of vitamin K1 in patients with unstable control under warfarin.. Effectiveness of Vitamin K1 supplementation was primarily assessed by the percentage (%) of Time-in-Therapeutic-Range (TTR) and secondarily by the standard deviation (SD) of the patient's INR values; the proportion of out-of-range INRs; and the number of dose changes on warfarin. Their change scores were obtained by subtracting the mean value in the 6 months pre-randomization from the mean value in the 6 months post-randomization. Multivariable linear-regressions identified factors associated with anticoagulation instability.. Fifty out of 54 patients were analyzed (intervention: n=26; placebo: n=24). Most indications (87%) for anticoagulation were venous thromboembolism (VTE). The intervention was associated with a greater reduction in the change scores for the SD of INRs between the pre and post-randomization periods compared with placebo. The mean change score was -0.259±0.307 with the intervention and -0.046±0.345 with placebo (p=0.026). There was no effect on the change scores of the (%) TTR (p=0.98), the number of INRs out-of-range (p=0.58) and the number of dose changes (p=0.604). Factors independently associated with increased variability in the SD of INRs were increased alcoholic drinks/week (p=0.017), dosing errors (p=0.0009) and missed INR appointments (p=0.035).. Vitamin K1 supplementation reduces the SD of INRs as an indicator of the variability in anticoagulation control in patients treated with warfarin for VTE.

Topics: Anticoagulants; Double-Blind Method; Drug Synergism; Female; Genotype; Humans; International Normalized Ratio; Male; Middle Aged; Placebos; Polymorphism, Genetic; Thrombosis; Treatment Outcome; Vitamin K 1; Warfarin

Topics: Acenocoumarol; Anti-Bacterial Agents; Blood Coagulation Tests; Clinical Trials as Topic; Coronary Disease; Coumarins; Dental Service, Hospital; Humans; Phenindione; Postoperative Complications; Thrombosis; Tooth Extraction; Vitamin K 1

Developing an optimal anticoagulant strategy poses a challenging task in patients with mechanical heart valves (MHVs) throughout their lifetime. We report an optimal anticoagulant therapy in a cancer patient with hepatic metastases after MHV replacement.. A 68-year-old female with MHVs suffered from gallbladder cancer with hepatic metastases. Her international normalized ratio (INR) fluctuated owing to the declined hepatic function.. Gallbladder cancer and hepatic metastases, with a history of mechanic aortic valve replacement and mitral valve replacement.. Warfarin was discontinued and Vitamin K1 was immediately administrated via intravenous infusion. low-molecular-weight heparin (LMWH) was regarded as a preferable option, and nadroparin at the dosage of 4100IU daily was administered.. No adverse event occurred during the patient's hospitalization and two-week follow up after discharge.. LMWH may represent a reasonable alternative regarding the inhibition of thrombus and bleeding in MHVs carriers with cancer and hepatic metastases.

Topics: Aged; Anticoagulants; Aortic Valve; Female; Gallbladder Neoplasms; Heart Valve Diseases; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Heparin, Low-Molecular-Weight; Humans; International Normalized Ratio; Liver Neoplasms; Mitral Valve; Postoperative Complications; Thrombosis; Vitamin K 1

To investigate the morbidity of complications and pregnancy outcomes in women with mechanical heart valve replacement who received low-dose oral anticoagulation treatment with warfarin throughout the pregnancy, compare the prognosis and complications of patients who were treated with single oral warfarin treatment or the "bridging" therapy treatment, investigate the influence of using vitamin K1 before emergency cesarean section delivery on postoperative warfarin anticoagulant effect and to explore an appropriate anticoagulant regimen during perioperative period for pregnant women with mechanical heart valve replacement.. 46 pregnant women with mechanical heart valve replacement who received low-dose oral anticoagulation treatment from October 2008 to October 2014 treated at West China Women's and Children's Hospital were retrospectively reviewed. Eight patients received emergency cesarean section (CS), while 38 patients received selective CS, in which 17 patients received single oral warfarin and 21 patients received "bridging" anticoagulation treatment during postoperative period. Morbidity of complications and the time to achieve the target INR after operation were compared.. The mechanical valves were at the mitral position in 35 (76.09 %) patients, at the aortic position in 2 (4.35 %) patient and at both the mitral and aortic position in 9 (19.57 %) patients. 46 full-term healthy babies were delivered and no maternal thromboembolic was observed during pregnancy. There was no significant difference of the amount of uterine bleeding between single oral warfarin group and "bridging" treatment group during postpartum period. In single oral warfarin group, one valve thrombosis was observed and led to sudden death. No periphery thrombosis, hematoma, general hemorrhage or other sign of over-anticoagulation was observed. The INR increased more slowly in the group who received emergency CS with preoperative application of vitamin K1 than other two groups.. The use of vitamin K1 preoperatively might result in warfarin resistance and discontinuation of warfarin therapy before selective CS might be more appropriate than application of vitamin K1. The "bridging" anticoagulation treatment which combines oral warfarin and subcutaneous LMWH might be more effective and safer than single oral warfarin therapy for patients with mechanical heart valve replacement during postoperative period, no matter selective or emergency CS. The safety of low-dose oral warfarin therapy throughout pregnancy is still under controversy.

Topics: Adult; Anticoagulants; Antifibrinolytic Agents; Cesarean Section; China; Delivery, Obstetric; Female; Heart Valve Diseases; Heart Valve Prosthesis Implantation; Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Morbidity; Perioperative Period; Postoperative Period; Pregnancy; Pregnancy Complications, Cardiovascular; Pregnancy Outcome; Thrombosis; Treatment Outcome; Vitamin K 1; Warfarin; Young Adult

Topics: Administration, Oral; Anticoagulants; Coumarins; Female; Follow-Up Studies; Humans; Male; Prospective Studies; Risk; Thrombosis; Time Factors; Vitamin K 1; Warfarin

Vitamin K is involved in the biosynthesis of a number of blood coagulation factors and bone proteins. It has been suggested that the vitamin K requirement of bone tissue is higher than that of the liver. Here we report that in rats very high doses of vitamin K affected neither the blood coagulation characteristics nor the blood platelet aggregation rate. This was observed for both phylloquinone and menaquinone-4. Both vitamers were also tested for their effects on the arterial thrombosis tendency in the rat aorta loop model. The mean obstruction times were prolonged at a high intake of menaquinone-4 (250 mg/kg body weight/day), and shortened after a similarly high phylloquinone regimen. Since (a) both vitamers only differ in their aliphatic side chains; and (b) a similar trend was observed after administration of phytol and geranylgeraniol, we conclude that the modulation of the arterial thrombosis tendency is accomplished by the side chain of vitamin K.

Topics: Animals; Blood Coagulation; Diet; Dietary Fats, Unsaturated; Disease Models, Animal; Disease Susceptibility; Diterpenes; Dose-Response Relationship, Drug; Male; Phytol; Platelet Aggregation; Rats; Rats, Wistar; Thrombosis; Vitamin K; Vitamin K 1; Vitamin K 2; Vitamin K Deficiency

Vitamin K is required to convert specific glutamyl residues in a limited number of proteins to gamma-carboxyglutamyl residues. The response of various measures of vitamin K insufficiency to the administration of 1 mg/d of the vitamin K antagonist warfarin was studied in two groups of nine older (55-75 y) or younger (20-28 y) subjects. The most consistent and extensive alteration was an increase in the concentration of serum under-gamma-carboxylated osteocalcin followed by increased immunochemical detection of plasma under-gamma-carboxylated prothrombin (PIVKA-II), and by a decreased urinary excretion of gamma-carboxyglutamic acid. Plasma concentrations of prothrombin were altered by this treatment but prothrombin times, factor VII activity, prothrombin F-1 x 2 concentrations, and a less sensitive assay for under-gamma-carboxylated prothrombine were not. The concentration of serum under-gamma-carboxylated osteocalcin was lower when subjects consumed 1 mg vitamin K/d than when they consumed their normal diet.

Topics: 1-Carboxyglutamic Acid; Adult; Aged; Anticoagulants; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Humans; Incidence; Male; Middle Aged; Osteocalcin; Prothrombin; Thrombosis; Vitamin K; Vitamin K 1; Warfarin

Topics: Animals; Blood Coagulation Disorders; Carotid Arteries; Hypoprothrombinemias; Prothrombin; Prothrombin Time; Rabbits; Thrombosis; Vitamin K 1; Warfarin

Topics: Anticoagulants; Blood Coagulation Tests; Ethyl Biscoumacetate; Heparin; Humans; Phenindione; Thrombosis; Vitamin K 1; Warfarin

Topics: Accidents; Anticoagulants; Antifibrinolytic Agents; Coumarins; Hemorrhage; Humans; Thrombosis; Vitamin K; Vitamin K 1