Impact on hepatic estrogen-sensitive proteins by a 1-year contraceptive vaginal ring delivering Nestorone® and ethinyl estradiol.

OBJECTIVES: Estrogen-sensitive hepatic proteins were assessed in women using a contraceptive vaginal ring (CVR) delivering 150mcg Nestorone® (NES) and 15mcg ethinyl estradiol (EE). STUDY DESIGN: A substudy of the Contraceptive Clinical Trials Network of the National Institute of Child Health and Human Development enrolled 129 participants, with assessments of factor VIII, fibrinogen, protein S (PS) and sex hormone binding globulin (SHBG). Thirty-six participants had used combined hormonal contraceptives (CHCs) in the cycle preceding first CVR use (recent users) and 70 had no history of recent use (nonusers). RESULTS: Mean values at baseline were within the normal range for all four proteins but were higher for factor VIII, fibrinogen and SHBG and significantly lower for PS in recent compared to nonusers. During NES/EE CVR use, factor VIII, fibrinogen and PS were within the normal range; however, SHBG levels were increased by nearly 100% at Cycle 13. The change from baseline to final evaluation was statistically significant for all proteins in nonusers. The change in recent users was significant for factor VIII at Cycle 6 and for SHBG at Cycles 6 and 13, but not for PS or fibrinogen. CONCLUSION: NES/EE CVR for up to 13cycles was associated with changes from baseline in plasma levels of factor VIII, fibrinogen and PS that were within the normal range, with SHBG levels above the normal range by Cycle 6. Nonusers of CHC before CVR showed wider changes in values versus recent users whose baseline values were increased by previous EE exposure. IMPLICATIONS: Recent use of CHCs demonstrated significant changes in all four measured hepatic proteins at baseline compared to nonusers. Use of the NES/EE CVR further changed these hepatic protein markers, but values remained within the normal range. Prebaseline exposure to estrogen can obscure interpretation of hepatic proteins changes associated with a second CHC.

[Venous thromboembolic risk during repatriation for medical reasons]. / Risque veineux thromboembolique et sa prévention lors d'un rapatriement sanitaire.

In France, approximately 3000 people are repatriated every year, either in a civil situation by insurers. Repatriation also concerns French army soldiers. The literature is scarce on the topic of venous thromboembolic risk and its prevention during repatriation for medical reasons, a common situation. Most studies have focused on the association between venous thrombosis and travel, a relationship recognized more than 60 years ago but still subject to debate. Examining the degree of venous thromboembolic risk during repatriation for medical reasons must take into account several parameters, related to the patient, to comorbid conditions and to repatriation modalities. Appropriate prevention must be determined on an individual basis.

Should women suffering from migraine with aura be screened for biological thrombophilia?: results from a cross-sectional French study.

INTRODUCTION: Migraine, particularly migraine with aura (MA), is associated with a higher risk for ischemic stroke (IS). A procoagulant state may predispose to IS. Whether inherited biological thrombophilia are associated with migraine risk remains controversial. OBJECTIVE: To assess the risk of migraine without or with aura related to inherited biological thrombophilia adjusted for the main potential confounders. MATERIAL AND METHODS: A cross-sectional study was conducted in 1456 French women aged 18 to 56years, referred for biological coagulation check-up because of personal or familial venous thrombosis history. Between April 2007 and December 2008, all women answered a self-administered questionnaire to determine whether they had headache. RESULTS: There were 294 (20%) migrainous sufferers (including 71 [5%] with MA), 975 (67%) non migrainous women and 187 (13%) non migrainous headache women. Inherited thrombophilia were detected in 576 (40%) women, including 389 (40%) non migrainous women, 90 (40%) migraine without aura (MWA), 33 (46%) MA women and 64 (34%) non migrainous headache women. Factor V Leiden (FVL) i.e. F5rs6025 or Factor II G20210A (FIIL) i.e. F2rs1799963 mutation was detected in 296 (30%) non migrainous women and in 100 (34%) migrainous women of which 27 had MA. There was a significant association between MA and FVL or FIIL mutations (adjusted OR=1.76 [95% CI 1.02-3.06] p=0.04) whereas this association in MWA and in non migrainous headache women was not significant. There was no significant association between migraine and other biological thrombophilia. CONCLUSION: FVL or FIIL mutations were more likely among patients suffering from MA. Whether biological thrombophilia screening should be systematically performed in women suffering from MA remains to be determined.

[Hemorrhagic accidents of the new oral anticoagulants and coagulation assays]. / Accidents hémorragiques des nouveaux anticoagulants oraux et examens de la coagulation.

New oral anticoagulants which specifically inhibit factor Xa (FXa) or thrombin (FIIa) do not require routine laboratory monitoring. However, they induce a state of hypocoagulation and increase the risk of bleeding. In some clinical situations, such as emergency surgery, hemorrhagic episodes, or recurrent stroke, coagulation monitoring may be useful. A significant number of publications have reported uncontrollable hemorrhagic complications and deaths in patients treated with these new anticoagulants. The selection of the most appropriate clotting assay is based on the drug used and the availability of the test. The new anticoagulants influence all global clot-based tests. Prothrombin time and partial thromboplastin time measured before and after treatment are considered as qualitative tests since they are not specific. Specific anti-Xa and anti-IIa assays are available and results can be expressed in nanogram per milliliter of plasma using calibrated plasmas containing well-established amounts of drug. The fact that there is no specific antidote to reverse the anticoagulant action of the new anticoagulants can impair management of hemorrhagic complications; clinical experience is still limited. Pro-hemostatic treatment with non-activated or activated prothrombin complexes (FEIBA(®)), or as a last recourse with FVIIa concentrates (NovoSeven(®)), has been used with variable results. Some suggestions for the management of patients with bleeding have been published but there is still little clinical evidence for these interventions.

Prevention and treatment of venous thromboembolism--International Consensus Statement.

The aim of this document is to provide a clear and concise account of the evidence regarding efficacy or harm for various methods available to prevent and manage venous thromboembolism (VTE).

Mortality and inherited thrombophilia: results from the European Prospective Cohort on Thrombophilia.

BACKGROUND: Data on the survival of individuals with hereditary thrombophilia are rare and only come from retrospective studies. OBJECTIVE: The aim of the present study was to assess mortality in individuals with known thrombophilia with and without a history of thrombosis in comparison to a control group. PATIENTS/METHODS: The European Prospective Cohort on Thrombophilia (EPCOT) study is a prospective, multi-center observational study performed to assess the risk of thrombosis in persons with inherited thrombophilia. In an extension of the present study, the vital status was assessed in 1240 individuals with thrombophilia (mean age 40.9 years, 59% women, 196 with antithrombin, 341 with protein C, 276 with protein S-deficiency, 330 with factor (F)V Leiden and 97 with combined defects, and 62% with a history of venous thrombosis [VT]) and 875 controls (mean age 42.5 years, 48% women, 7% with a history of VT). RESULTS: Seventy-two individuals with thrombophilia and 45 controls died during follow-up. The risk of death, adjusted for gender, thrombosis history and center, was not associated with thrombophilia (hazard ratio [HR] thrombophilia individuals vs. controls: 1.09, 95% confidence interval [CI] 0.66-1.78). When individuals with thrombophilia were evaluated separately, a history of thrombosis was not associated with mortality: the risk of death after adjustment for gender, anticoagulation and center was HR 0.79 (95% CI, 0.41-1.54). CONCLUSIONS: No increased risk of death in individuals with thrombophilia, not even in those with a history of thrombosis, was observed.

[Pharmacologic heterogeneity of new anticoagulants]. / Hétérogénéité pharmacologique des nouveaux anticoagulants.

Amongst numerous promising anticoagulant molecules, rivaroxaban (Xarelto(®)), dabigatran (Pradaxa(®)) and apixaban (Eliquis(®)) have been registered outside the USA in the prevention of thromboembolic events in patients undergoing total hip or knee prosthetic replacement. Rivaroxaban however has been granted authorisation by the FDA for the thromboprophylaxis after surgery for total hip or knee surgery. Dabigatran has been granted authorisation by the FDA in non-valvular atrial fibrillation (RE-LY trial) while rivaroxaban is expecting approval in this same indication (ROCKET trial). Phase III results in the treatment and in the secondary prevention of established venous thrombosis and pulmonary embolism are encouraging. These small molecules are obtained by chemical synthesis, their molecular weight is lower than 500 daltons. Many coagulation tests may be affected by these molecules. Those modifications should be known in order to avoid misinterpretation of the tests but could also be used to measure plasma concentrations of these products. The choice of a non specific global and readily available test has been documented (Quick time for rivaroxaban and aPTT for dabigatran). Anti-Xa (for rivaroxaban) and anti-IIa (for dabigatran) activities should however be preferred, expressed in ng/ml with calibrated plasmas (containing predetermined concentration of the tested drug). The half-life is around 8 to 12 hours, with a peak activity 2 to 4 hours after ingestion. Dabigatran is mainly eliminated via the kidney, hence requiring dose-adjustment in case of moderate renal insufficiency, and contra-indicated in case of severe renal insufficiency. Rivaroxaban being excreted via kidney and liver, some precautions should apply in case of liver insufficiency. No data are available in pregnancy or pediatrics, clinical trials are ongoing. There are few interactions with concomitant drugs, which should not be ignored. The short half-life of these new agents compensates for the lack of any specific antidote in many instances. Their oral administration, without the need for dose adjustment, and without requirement for a laboratory monitoring will increase their use in a large number of patients, in those indications for which an approval has been granted by health authorities.

[Thrombosis and assisted reproductive techniques (ART)]. / Thrombose et assistance médicale à la procréation (AMP).

Assisted reproductive techniques (ART) concern procedures designed to increase fertility of couples: artificial insemination, in vitro fertilization (IVF), either classical or after intracytoplasmic sperm injection (ICSI), transfer of frozen embryos, or gamete intrafallopian transfer. Their use has greatly increased these last years. They may be associated with severe ovarian hyperstimulation syndrome and one possible major complication is venous or arterial thrombosis. Thromboses are rare but potentially serious with important sequellae. They are mostly observed in unusual sites such as head and neck vessels and the mechanism is still unknown although hypotheses have been proposed. This review is an update of our knowledge and an attempt to consider guidelines for the prevention and treatment of ART-associated thromboses, which frequently occur when the woman is pregnant. Prevention of severe ovarian hyperstimulation by appropriate stimulation procedures, detection of women at risk of hyperstimulation and of women at high risk of thrombosis should allow reduction of the risk of thrombosis, possibly by administration of a thromboprophylaxis at a timing and dose which can be only determined by extrapolation.

[Two new anticoagulants available in 2010--Dabigatran Etexilate and Rivaroxaban: expected progresses--raised problems]. / Deux nouveaux anticoagulants disponibles en 2010--Dabigatran Etexilate et Rivaroxaban: progrès attendus--problèmes posés.

After having been used for decades, heparins (unfractionated heparin [UFH] or low molecular weight heparins [LMWH]) and vitamin K antagonists (VKA), which are only parenterally active or which are responsible for frequent iatrogenicity respectively, have to face the competition of new anticoagulant drugs targeting either factor Xa or factor IIa (thrombin). Rivaroxaban (Xarelto(®)) and Dabigatran Etexilate (Pradaxa(®)) are the two leading components. They are more convenient to use and do not require routine coagulation monitoring. They are already marketed for venous thromboembolism prevention in major orthopaedic surgery. Although manufacturers claim that no biological monitoring is required, these two compounds may interfere in routine coagulation tests such as PT or aPTT, and in esoteric assays such as anti-Xa activity (the results of which are usually expressed in international anti-Xa units either UFH or LMWH unit) for Rivaroxaban or anti-IIa activity for Dabigatran Etexilate. Noteworthy is the fact that, in the case of these new anticoagulant drugs, results should be expressed in active product units (nanogram per millilitre of Rivaroxaban or Dabigatran). The new anticoagulants are associated with a bleeding risk comparable to that of VKA and heparins.

[Perioperative use of antithrombotic agents: recommendations of the American College of Chest Physicians (ACCP) and the French Superior Health Authority (HAS)]. / La prise en charge périopératoire des traitements antithrombotiques. Des recommandations de l'American College of Chest Physicians (ACCP) à celles de la Haute Autorité de santé (HAS).

The purpose of this work was to analyse management practices for patients given anticoagulants or antiplatelet agents such as aspirin, clopidogrel and who are to undergo an invasive procedure or surgery. The modalities for the transition from oral agents to low-molecular-weight-heparin (LMWH) or unfractionated heparin (UFH) are studied. The recommendations or suggestions using the ACCP score: grade 1 recommendations are strongly motivated and indicate whether the benefit overbalances or not the risk, the burden, and the cost of the treatment. Grade 2 recommendations are considered to be suggestions. They imply that the individual physician chooses between different therapeutic strategies. For the purpose of this work, the most important recommendations are the following:

Cardiovascular risk markers during treatment with estradiol and trimegestone or dydrogesterone.

OBJECTIVE: To study cardiovascular risk markers in women taking estradiol/trimegestone or estradiol/dydrogesterone. DESIGN: Multicenter, randomized, prospective, double-blind study of 184 healthy post-menopausal women randomized to 6 cycles of either estradiol (2mg)+trimegestone (0.5mg) (T-group) or estradiol (2mg)+dydrogesterone (10mg) (DYDR group). Cardiovascular risk markers were measured before, after cycle 1, 3 and 6 and at 4 weeks post-treatment. RESULTS: Fibrinogen was reduced in both groups but more markedly in the DYDR group. Factor VIIc activity levels decreased in both groups with a greater change in the T-group. Factor VII antigen was increased in both groups with a greater increase in the DYDR group. Factor VIIa was increased in the DYDR group only. Plasminogen levels were also increased in both groups with a greater increase in the T-group. There were no statistically significant changes in lipid variables between the different regimens. Changes in total cholesterol and LDL cholesterol were correlated positively with changes in factor VIIc in the DYDR group and negatively with changes in factor VIIc in the T-group. Trigemestone was associated with a better bleeding pattern. CONCLUSIONS: Trimegestone was associated with less procoagulant changes in factor VIIa and factor VIIc activity and larger decrease in PAI-1 activity compared with the dydrogesterone preparation. These results reflect less androgenic properties of the trimegestone preparation. The fibrinogen level and Lp(a) were more decreased during dydrogesterone treatment. Further investigation is required to clarify the relative importance of beneficial effects with respect to cardiovascular risk.

[Pregnancy and venous thromboembolism. North-American and European guidelines. American College of Chest Physicians]. / Grossesse et maladie thromboembolique veineuse. A propos des recommandations nord-américaines eteuropéennes.

Guidelines concerning the prevention and treatment of pregnancy-associated venous thromboembolism (VTE) have been elaborated by the American College of Chest Physicians and published in Chest in 2008. In this review, they have been compared with European guidelines and discussed taking into account the papers published since 2008.Most recommendations are of low grade of evidence because randomized studies are lacking during pregnancy and many reflect guidelines proposed by experts. The decisions on the most appropriate prophylaxis, dose to be administered and moment of pregnancy for starting prophylaxis are often decided case by case after careful assessment of the risk of pregnancy-associated VTE, on one hand, and the risk for the mother, on the other.Risk factors (age >or= 35, obesity, history of VTE with or without sequellae, in vitro fertilization)or thrombophilia have to be taken into account. Scores have been proposed to improve standardisation and evaluation of the risk of VTE and they should be validated.

[Congenital protein S deficiencies; diagnostic difficulties]. / Les déficits congénitaux en protéineS ; difficultés diagnostiques.

Protein S is a physiologic inhibitor of coagulation acting as a cofactor of activated protein C (APC) that inhibits factor Va and VIII. Approximately 60% of PS is bound to C4bBP, a protein of the complement system and only the free PS has a cofactor PCa role. Congenital PS deficiencies are diagnosed by immunologic dosage of free and total PS and functional assay evaluating APC cofactor activity. However, it has been demonstrated a direct anticoagulant activity of free PS, non-dependant of APC on the cascade coagulation and even PS bound to C4bBP seems to have anticoagulant properties. So, it appears that functional assays available estimate only a part of PS anticoagulant activities and, in addition, many interferences are reported with these tests (lupus anticoagulant, factor V Leiden, factor VIII excess...). Immunologic dosages are more reliable in spite of rare qualitative PS deficiencies that could be non-diagnosed. PS deficiencies are often difficult to diagnose because of an overlapping between normal and pathological values. Familial studies are necessary to prove the hereditary origin because there are several causes of acquired and sometimes persistent PS deficiencies (liver insufficiency, vitamin K absence, hormonal therapy in women, PS auto immune deficiency). About 200 different mutations were retrieved and, therefore, molecular studies are not of current practice. It is recommended currently to measure in first intention the free PS, if possible in association with PCa cofactor activity.

Predictors of increased PaCO2 during immersed prone exercise at 4.7 ATA.

During diving, arterial Pco(2) (Pa(CO(2))) levels can increase and contribute to psychomotor impairment and unconsciousness. This study was designed to investigate the effects of the hypercapnic ventilatory response (HCVR), exercise, inspired Po(2), and externally applied transrespiratory pressure (P(tr)) on Pa(CO(2)) during immersed prone exercise in subjects breathing oxygen-nitrogen mixes at 4.7 ATA. Twenty-five subjects were studied at rest and during 6 min of exercise while dry and submersed at 1 ATA and during exercise submersed at 4.7 ATA. At 4.7 ATA, subsets of the 25 subjects (9-10 for each condition) exercised as P(tr) was varied between +10, 0, and -10 cmH(2)O; breathing gas Po(2) was 0.7, 1.0, and 1.3 ATA; and inspiratory and expiratory breathing resistances were varied using 14.9-, 11.6-, and 10.2-mm-diameter-aperture disks. During exercise, Pa(CO(2)) (Torr) increased from 31.5 +/- 4.1 (mean +/- SD for all subjects) dry to 34.2 +/- 4.8 (P = 0.02) submersed, to 46.1 +/- 5.9 (P < 0.001) at 4.7 ATA during air breathing and to 49.9 +/- 5.4 (P < 0.001 vs. 1 ATA) during breathing with high external resistance. There was no significant effect of inspired Po(2) or P(tr) on Pa(CO(2)) or minute ventilation (Ve). Ve (l/min) decreased from 89.2 +/- 22.9 dry to 76.3 +/- 20.5 (P = 0.02) submersed, to 61.6 +/- 13.9 (P < 0.001) at 4.7 ATA during air breathing and to 49.2 +/- 7.3 (P < 0.001) during breathing with resistance. We conclude that the major contributors to increased Pa(CO(2)) during exercise at 4.7 ATA are increased depth and external respiratory resistance. HCVR and maximal O(2) consumption were also weakly predictive. The effects of P(tr), inspired Po(2), and O(2) consumption during short-term exercise were not significant.

[Thrombophilias and peripheral arterial occlusive disease]. / Thrombophilies et artériopathie oblitérante des membres inférieurs.

Peripheral arterial occlusive disease is a frequent disease due to the classical vascular risk factors such as smoking, diabetes mellitus, dyslipidemia, and hypertension. Despite these risk factors, many thrombophilias (physiological inhibitors defects, Factor V Leiden and 20210A prothrombin gene variant, antiphospholipid antibodies, mild hyperhomocysteinemia 15-30micromol/l) can be evoked in some clinical forms of peripheral arterial occlusive disease. This paper provides a synthesis of the published data about this topic. Screening for these thrombophilias is justified in patients with venous thromboembolic disease, or signs of antiphospholipid syndrome and possibly in different situations such as premature atheroma of lower limbs, chronic ischaemia, evolutive disease despite adapted treatment and revascularisation failures without evident technical explanation. Except for the antiphospholipid syndrome, there is currently no consensus for systematic screening of thrombophilia and treatment in patients with peripheral arterial occlusive disease.

[Hormonal contraception and risk of venous thromboembolism: When to ask for an assessment of hemostasis? Which parameters?]. / Contraception hormonale et risque thromboembolique veineux : quand demander une étude de l'hémostase ? Et laquelle ?

One of the deleterious effects of the combined oral contraceptives is venous thromboembolism (VTE) and it is the most frequent. VTE is potentially serious because it is sometimes responsible for fatal pulmonary embolism. Because of the large use of hormonal contraception among healthy women and often for long durations, it is fundamental to target the prescriptions and detect women at high risk of VTE. It has been demonstrated that some congenital or acquired coagulation anomalies are associated with an increase of thromboembolic risk. In addition, combined oral contraceptives modify some parameters of the hemostasis, whatever the route of administration. In order to optimize the benefit-risk balance of oral contraception, the search for a biological thrombophilia is essential in some clinical situations such as in young women with a history of venous thromboembolic event or with a family history of thrombosis at a relatively young age. A thorough questioning must be performed. On the other hand, this biological research is not systematically recommended before any prescription of hormonal contraception in patients having neither previous personal nor family history of venous thrombosis.

Changes in enoxaparin pharmacokinetics during pregnancy and implications for antithrombotic therapeutic strategy.

Enoxaparin is frequently prescribed for pregnant women who are at high risk for thromboembolic complications. We conducted a population pharmacokinetics study with 75 pregnant women and 38 nonpregnant women as controls to evaluate enoxaparin pharmacokinetics during pregnancy and the postpartum period. Clearance of the drug was higher in the pregnant women throughout pregnancy when compared with nonpregnant women (0.78 +/- 0.03 l/h vs. 0.52 +/- 0.03 l/h, respectively P < 0.001) with the stage of the pregnancy having no influence. The volume of distribution was influenced by stage of the pregnancy, characterized by a two-step increase, with an initial rise paralleling the woman's increase in body weight during the first two trimesters, followed by an additional increase of 41% during the last 2 months of pregnancy, independent of changes in weight. Using enoxaparin pharmacokinetic parameters to simulate anti-Xa time profiles, we observed that the maintenance of the same doses throughout pregnancy resulted in a progressive reduction in mean and peak anti-Xa activities. We recommend the administration of doses normalized for body weight changes so as to counteract enoxaparin pharmacokinetic changes that accompany various stages of pregnancy.