Examining the transplacental passage of apixaban using the dually perfused human placenta

When Direct Oral Anticoagulants Should Not Be Standard Treatment: JACC State-of-the-Art Review

For most patients, direct oral anticoagulants (DOACs) are preferred over vitamin K antagonists for stroke prevention in atrial fibrillation and for venous thromboembolism treatment. However, randomized controlled trials suggest that DOACs may not be as efficacious or as safe as the current standard of care in conditions such as mechanical heart valves, thrombotic antiphospholipid syndrome, and atrial fibrillation associated with rheumatic heart disease. DOACs do not provide a net benefit in conditions such as embolic stroke of undetermined source. Their efficacy is uncertain for conditions such as left ventricular thrombus, catheter-associated deep vein thrombosis, cerebral venous sinus thrombosis, and for patients with atrial fibrillation or venous thrombosis who have end-stage renal disease. This paper provides an evidence-based review of randomized controlled trials on DOACs, detailing when they have demonstrated efficacy and safety, when DOACs should not be the standard of care, where their safety and efficacy are uncertain, and areas requiring further research.

First Trimester Anticoagulant Exposure and Adverse Pregnancy Outcomes in Women with Preconception Venous Thromboembolism: A Nationwide Cohort Study

OBJECTIVE

The purpose of this study was to investigate first trimester anticoagulant exposure and risks of adverse pregnancy-related and fetal outcomes.

METHODS

Using Danish nationwide registries, we identified all pregnant women with preconception venous thromboembolism, 2000-2017, and linked data on exposure to low-molecular-weight heparin (LMWH), vitamin K antagonist (VKA), or non-VKA oral anticoagulant (NOAC) during pregnancy. We assessed pregnancy-related and fetal outcomes associated with first trimester anticoagulant exposure.

RESULTS

Among 4490 pregnancies in women with preconception venous thromboembolism (mean age 31 years, 40% nulliparous) during the first trimester, 63.1% were unexposed, 25.9% were exposed to LMWH, 10.4% VKA, and 0.6% NOAC. Adverse outcomes were lowest in unexposed and LMWH exposed. Compared with unexposed, VKA was associated with higher risks of preterm (adjusted odds ratio [OR] 2.26; 95% confidence interval [CI], 1.70-2.99) and very preterm birth (adjusted OR 3.78; 95% CI, 1.91-7.49), shorter mean gestational age was associated with VKA (-7.5 days; 95% CI, -9.1 to -5.9 days) or NOAC (-2.3 days; 95% CI, -8.4-3.8), and lower mean birthweight with VKA (-55 g; 95% CI, -103.1 to -8.5) or NOAC (-190 g; 95% CI, -364.1 to -16.4). Adjusted ORs for small-for-gestational-age infants were 1.07 (95% CI, 0.77-1.50) with VKA, and 3.29 (95% CI, 1.26-7.95) with NOAC. Mean 5-minute Apgar score (9.8) and congenital defect prevalence (8.4%-10%) varied little across exposure groups.

CONCLUSIONS

Fetal risk was lowest in unexposed and LMWH-exposed pregnancies, supporting the recommendation of LMWH during pregnancy. NOAC safety during pregnancy is unclear due to the rarity of NOAC exposure.

Prophylaxis and management of venous thromboembolism during pregnancy and postpartum period

Introduction. Venous thromboembolism (VTE) is one of the lead causes for maternal mortality and morbidity during pregnancy in the majority of developed countries. The incidence rate of VTE per pregnancy-year increases during pregnancy and postpartum period about by 4-fold and at least 14-fold, respectively.

Aim: to analyze and summarize current view on risk factors of thrombotic events during gestation and to discuss recent guidelines for the management of venous thromboembolic complications during pregnancy and postpartum, by taking into account a balance between risks and benefits of using anticoagulants.

Materials and Methods. The literature search covering the last 10 years was carried out in the electronic scientific databases RSCI, PubMed/MEDLINE, and Embase. While formulating a search strategy for evidence-based information, the PICO method (P = Patient; I = Intervention; C = Comparison; O = Outcome) and the key terms “venous thromboembolism” and “pregnancy” were used.

Results. Risk factors were found to include a personal history of VTE, verified inherited or acquired thrombophilia, a family history of VTE and general medical conditions, such as immobilization, overweight, varicose veins, some hematological diseases and autoimmune disorders. VTE is considered being potentially preventable upon prophylactic administration of anticoagulants, but no high confidence randomized clinical trials comparing diverse strategies of thromboprophylaxis in pregnant women have been proposed so far. Because heparins do not cross the placenta, weight-adjusted therapeutic-dose low molecular weight heparins (LMWH) represent the anticoagulant treatment of choice for VTE during pregnancy. Once- and twice-daily dosing regimens are acceptable. However, no evidence suggesting benefits for measurement of factor Xa activities and consecutive LMWH dose adjustments to improve clinical outcomes are available. In case of uncomplicated pregnancy-related VTE, no routine administration of vitamin K antagonists, direct thrombin or factor Xa inhibitors, fondaparinux, or danaparoid is recommended. Lactating women may switch from applying LMWH to warfarin. Anticoagulation therapy should be continued for 6 weeks postpartum with total duration lasting at least for 3 months.

Conclusion. VTE is a challenging task in pregnant women expecting to apply a multi-faceted approach for its efficient solution by taking into account updated recommendations and personalized patient-oriented features.

Challenging anticoagulation cases: A case of heparin-induced-thrombocytopenia in the first trimester of pregnancy

Heparin-induced thrombocytopenia in pregnancy is an uncommon phenomenon which rarely occurs in the first trimester. Therapeutic options and duration of therapeutic anticoagulation are varied amongst reported published cases. We report a 41-year-old female with confirmed HIT following anticoagulation with dalteparin for deep vein thrombosis (DVT). She was treated with therapeutic fondaparinux for 3 months followed by prophylaxis dosage until delivery and for 6 weeks thereafter. A review of reported cases of the development of HIT in the first trimester and subsequent clinical management is discussed.

Direct Oral Anticoagulants: From Randomized Clinical Trials to Real-World Clinical Practice

Direct oral anticoagulants (DOACs) are a more manageable alternative than vitamin K antagonists (VKAs) to prevent stroke in patients with nonvalvular atrial fibrillation and to prevent and treat venous thromboembolism. Despite their widespread use in clinical practice, there are still some unresolved issues on optimizing their use in particular clinical settings. Herein, we reviewed the current clinical evidence on uses of DOACs from pharmacology and clinical indications to safety and practical issues such as drugs and food interactions. Dabigatran is the DOAC most affected by interactions with drugs and food, although all DOACs demonstrate a favorable pharmacokinetic profile. Management issues associated with perioperative procedures, bleeding treatment, and special populations (pregnancy, renal and hepatic impairment, elderly, and oncologic patients) have been discussed. Literature evidence shows that DOACs are at least as effective as VKAs, with a favorable safety profile; data are particularly encouraging in using low doses of edoxaban in elderly patients, and edoxaban and rivaroxaban in the treatment of venous thromboembolism in oncologic patients. In the next year, DOAC clinical indications are likely to be further extended.

Atrial fibrillation during pregnancy: a 9-month period with limited options

Pregnancy is a physiological condition with reversible hemodynamic, neurohormonal and coagulation changes to the maternal body during this 9‑month period. The occurrence of atrial fibrillation (AF) is altogether rare among pregnant women, but necessitates immediate treatment und further work-up. Despite numerous pharmacological and invasive therapeutic modalities for AF in non-pregnant patients, very few options are considered safe enough for the fetus and the mother during pregnancy. Commonly used medications such as beta blockers, calcium channel antagonists, antiarrhythmic drugs and anticoagulation therapy must be carefully individualized according to the week of gestation and possible underlying comorbidities of the mother, thus highlighting the importance of an interdisciplinary evaluation by a cardiologist and a gynecologist. The current review summarizes the existing knowledge and treatment options for AF in pregnancy and suggests a simplified algorithm for this clinical constellation.

Chiral Transplacental Pharmacokinetics of Fexofenadine: Impact of P-Glycoprotein Inhibitor Fluoxetine Using the Human Placental Perfusion Model

PURPOSE

Fexofenadine is a well-identified in vivo probe substrate of P-glycoprotein (P-gp) and/or organic anion transporting polypeptide (OATP). This work aimed to investigate the transplacental pharmacokinetics of fexofenadine enantiomers with and without the selective P-gp inhibitor fluoxetine.

METHODS

The chiral transplacental pharmacokinetics of fexofenadine-fluoxetine interaction was determined using the ex vivo human placenta perfusion model (n = 4). In the Control period, racemic fexofenadine (75 ng of each enantiomer/ml) was added in the maternal circuit. In the Interaction period, racemic fluoxetine (50 ng of each enantiomer/mL) and racemic fexofenadine (75 ng of each enantiomer/mL) were added to the maternal circulation. In both periods, maternal and fetal perfusate samples were taken over 90 min.

RESULTS

The (S)-(-)- and (R)-(+)-fexofenadine fetal-to-maternal ratio values in Control and Interaction periods were similar (~0.18). The placental transfer rates were similar between (S)-(-)- and (R)-(+)-fexofenadine in both Control (0.0024 vs 0.0019 min^-1) and Interaction (0.0019 vs 0.0021 min^-1) periods. In both Control and Interaction periods, the enantiomeric fexofenadine ratios [R-(+)/S-(-)] were approximately 1.

CONCLUSIONS

Our study showed a low extent, slow rate of non-enantioselective placental transfer of fexofenadine enantiomers, indicating a limited fetal fexofenadine exposure mediated by placental P-gp and/or OATP2B1. The fluoxetine interaction did not affect the non-enantioselective transplacental transfer of fexofenadine. The ex vivo placental perfusion model accurately predicts in vivo placental transfer of fexofenadine enantiomers with remarkably similar values (~0.17), and thus estimates the limited fetal exposure.

[Direct oral anticoagulants and pregnancy]

The use of direct oral anticoagulants, apixaban, dabigatran and rivaroxaban, is increasing because of their simpler way of use than those of low molecular weight heparins and of antivitamines K anticoagulants. During pregnancy, although there is no warning signal to date, the data on their use are far from sufficient to allow the continuation or initiation of direct oral anticoagulant treatment in a pregnant women.

Pulmonary Embolism in Pregnancy

Even though venous thromboembolism is a leading cause of maternal mortality in high-income countries, there are limited high-quality data to assist clinicians with the management of pulmonary embolism in this patient population. Diagnosis, prevention, and treatment of pregnancy-associated pulmonary embolism are complicated by the need to consider fetal, as well as maternal, well-being. Recent studies suggest that clinical prediction rules and D-dimer testing can reduce the need for diagnostic imaging in a subset of patients. Low-molecular-weight heparin is the preferred anticoagulant for both prophylaxis and treatment in this setting. Direct oral anticoagulants are contraindicated during pregnancy and in breastfeeding women. Thrombolysis or embolectomy should be considered for pregnant women with pulmonary embolism complicated by hemodynamic instability. Treatment of pregnancy-associated pulmonary embolism should be continued for at least 3 months, including 6 weeks postpartum. Management of anticoagulants at the time of delivery should involve a multidisciplinary individualized approach that uses shared decision making to take patient and caregiver values and preferences into account.

Prevention of Venous Thromboembolism during Pregnancy and the Puerperium with a Special Focus on Women with Hereditary Thrombophilia or Prior VTE-Position Paper of the Working Group in Women's Health of the Society of Thrombosis and Haemostasis (GTH)

Venous thromboembolism (VTE) is a major cause of maternal morbidity during pregnancy and the postpartum period. Because there is a lack of adequate study data, management strategies for the prevention of VTE during pregnancy have mainly been deduced from case-control and observational studies and extrapolated from recommendations for non-pregnant patients. The decision for or against pharmacologic thromboprophylaxis must be made on an individual basis weighing the risk of VTE against the risk of adverse side effects such as severe bleeding complications. A comprehensive, multidisciplinary approach is often essential as the clinical scenario is made more complex by the specific obstetric context, especially in the peripartum period. As members of the Working Group in Women's Health of the Society of Thrombosis and Haemostasis (GTH), we summarize the evidence from the available literature and aim to establish a more uniform strategy for VTE risk assessment and thromboprophylaxis in pregnancy and the puerperium. In this document, we focus on women with hereditary thrombophilia, prior VTE and the use of anticoagulants that can safely be applied during pregnancy and the lactation period.

Apixaban therapy in a pregnant woman with heparin-induced thrombocytopenia and venous thromboembolic events caused by congenital antithrombin deficiency: A case report

We report the case of a 35-year-old pregnant woman (gravida 3, para 1) with antithrombin deficiency who was successfully treated with apixaban. She had a history of heparin-induced thrombocytopenia and venous thromboembolic events. Pregnancy was confirmed while the patient was having anticoagulant therapy for a persistent thrombus. Choice of anticoagulation during her pregnancy was limited because of her antithrombin deficiency: heparin was not an option because of her history of heparin-induced thrombocytopenia; antithrombin-dependent anticoagulant drugs were not an option because of her antithrombin deficiency, and she preferred outpatient management. Despite the fact that there are no reports of its use in pregnant women, we selected apixaban (10 mg/day), a direct Xa inhibitor, as the best solution. No progression of thrombus was noted during the pregnancy. The newborn baby had no external congenital anomalies, intracranial hemorrhage, or bleeding tendency. Thus, apixaban may be a candidate for anticoagulant therapy in pregnant women with a history of venous thromboembolic events and heparin-induced thrombocytopenia.

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Pregnant women are at higher risk for venous thromboembolism than women who are not pregnant.

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Anticoagulant therapy is limited for a pregnant woman with heparin-induced thrombocytopenia caused by congenital antithrombin deficiency.

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Apixaban may be an alternative option of anticoagulant therapy during pregnancy.

Thrombosis and hemostasis health in pregnancy: Registries from the International Society on Thrombosis and Haemostasis

Online patient registries are used to collect data on clinical conditions with rare occurrence or unclear diagnostic and management practices. The success of these registries depends on clear definition of goals, correct identification of patient population/inclusion criteria, availability of appropriate setup and maintenance tools, and the quality of dissemination. The Scientific and Standardization Committee (SSC) for Women's Health Issues in Thrombosis and Hemostasis, one of 20 committees of the International Society on Thrombosis and Haemostasis (ISTH) has developed 6 registries for women's bleeding and thrombotic conditions over the past 2 years and are currently in various stages of progress. Here, we provide information about these registries, including rationale, objectives, and methods for data collection. The aim is to enhance worldwide participation and thus promote the success of these registries. We used ISTH REDCap, a mature and secure Web application for building and managing online surveys and databases, and the ISTH advertising platform to maximize participation. Registries (links and project details available on ISTH and Women's SSC Web sites) include: (1) WiTEAM, project on thrombophilia and placenta-mediated obstetric complications; (2) a registry for disseminated intravascular coagulation in pregnancy; (3) severe congenital protein C deficiency-an obstetric study; (4) obstetric and gynecologic outcomes of women with platelet function disorders; (5) thrombolysis and invasive treatments for massive pregnancy-related pulmonary embolism; (6) pregnancy and exposure to direct oral anticoagulants. The ISTH promotes online registries on women's issues to enhance understanding of current practices, identify knowledge gaps, promote research, and ultimately improve patient safety and quality of life.

ACOG Practice Bulletin No. 196: Thromboembolism in Pregnancy

Women who are pregnant or in the postpartum period have a fourfold to fivefold increased risk of thromboembolism compared with nonpregnant women (). Approximately 80% of thromboembolic events in pregnancy are venous (), with a prevalence of 0.5-2.0 per 1,000 pregnant women (). Venous thromboembolism (VTE) is one of the leading causes of maternal mortality in the United States, accounting for 9.3% of all maternal deaths ().The prevalence and severity of this condition during pregnancy and the peripartum period warrant special consideration of management and therapy. Such therapy includes the treatment of acute thrombotic events and prophylaxis for those at increased risk of thrombotic events. The purpose of this document is to provide information regarding the risk factors, diagnosis, management, and prevention of thromboembolism, particularly VTE in pregnancy. This Practice Bulletin has been revised to reflect updated guidance regarding screening for thromboembolism risk and management of anticoagulation around the time of delivery.

Direct-acting oral anticoagulants (DOACs) in pregnancy: new insight from VigiBase®

We aimed to perform an analysis of individual case safety reports retrieved after the Standardized MedDRA Query “Pregnancy and neonatal topics” for which Direct-Acting Oral Anticoagulants (DOACs) were claimed as suspected/interacting drugs. Additionally, to investigate if exists a disproportion of cases reporting “Pregnancy and neonatal topics” adverse events rather than other adverse events for DOACs in comparison with all other drugs registered in VigiBase or warfarin. VigiBase, the World Health Organization (WHO)’s global database of individual case safety reports was used as data source. Forty-two cases of abortion were detected of which 18 (42.8%) had alternative causes for its occurrence. Fourteen cases reported congenital anomaly (8 cases) or low birth weight baby/fetal growth restriction (6 cases) of which 62.5% and 33.3% had at least one confounder, respectively. In the disproportionality analyses, a potential safety signal for spontaneous abortion emerged for rivaroxaban (Reporting Odds Ratio, ROR 2.70; 95% CI 1.79–4.07) and apixaban (ROR 6.76; 95% CI 2.99–15.25). However, when the same analyses were performed using only cases without alternative causes, no statistically significant associations for rivaroxaban when compared to all other drugs (ROR 1.05; 95% CI 0.54–2.02) or warfarin (ROR 0.79; 95% CI 0.47–1.32) were found. For apixaban, we found a statistically significant ROR for induced abortion when compared to all other drugs or warfarin. For the majority of cases claiming DOACs-induced teratogenic effects, spontaneous or induced abortion there was at least one alternative cause explaining the occurrence of the adverse events. For rivaroxaban, when cases without confounders were considered, no safety signals emerged. However, for apixaban, we found a potential safety signal suggesting an increased probability of reporting spontaneous/induced abortion rather than other events when compared to all other drugs or warfarin.

Pregnancy and Pulmonary Embolism

Venous thromboembolism (VTE), referring to both deep vein thrombosis and pulmonary embolism, is a leading cause of death in the developed world during pregnancy. This increased risk is attributed to the Virchow triad, inherited thrombophilias, along with other standard risk factors, and continues for up to 6 to 12 weeks postpartum. During the peripartum period, women should be risk stratified and preventive measures should be initiated based on their risk. Diagnostic tests and treatment strategies commonly used in VTE differ in pregnancy. An understanding of these differences is imperative to diagnose with confidence and to treat appropriately.

An evidence-based approach to pre-pregnancy counselling for patients with systemic lupus erythematosus

Patients with SLE are often young females of childbearing age and a pregnancy wish in this patient group is common. However, SLE patients are at high risk for adverse pregnancy outcomes that require adequate guidance. It is widely acknowledged that pre-pregnancy counselling is the pivotal first step in the management of SLE patients with a wish to become pregnant. Next, management of these patients is usually multidisciplinary and often requires specific expertise from the different physicians involved. Very recently a EULAR recommendation was published emphasizing the need for adequate preconception counselling and risk stratification. Therefore the present review specifically addresses the issue of pre-pregnancy counselling for SLE patients with an evidence-based approach. The review summarizes data retrieved from recently published, high-quality cohort studies that have contributed to a better understanding and estimation of pregnancy-related risks for SLE patients. The present review categorizes risks from a patient-oriented point of view, that is, the influence of pregnancy on SLE, of SLE on pregnancy, of SLE on the foetus/neonate and of SLE-related medication. Lastly, pre-pregnancy counselling of SLE patients with additional secondary APS is reviewed. Collectively these data can guide clinicians to formulate appropriate preventive strategies and patient-tailored monitoring plans during pre-pregnancy counselling of SLE patients.

Anticoagulants in frail patients. Seven situations at risk

In the case of venous thromboembolic disease (VTE), physicians are facing more and more difficulties in managing VTE and their treatment in frail patients. These patients could present several risk situations such as: chronic kidney disease (CKD), underweight or malnourished, falls, cognitive impairment, multi-medicated patients, cancer and pregnancy. Guidelines typically recommend anticoagulation. There are multiple challenges in the safe use of anticoagulation in frail patients, including bleeding risk, monitoring and adherence, and polypharmacy. The objective of this review is to explore these at-risk situations and to suggest adequate anticoagulation therapy, when possible, in each of these complex situations.

Preventing venous thromboembolism during pregnancy and postpartum: crossing the threshold

When should a patient with a known thrombophilia or prior venous thromboembolism (VTE) receive low-molecular-weight heparin (LMWH) prophylaxis during pregnancy and/or the postpartum period? Accurately predicting thrombotic and bleeding risks and knowing what to do with this information is at the heart of decision-making in these challenging scenarios. This article will explore the concept of a risk threshold from clinician and patient perspectives and provide guidance for the use of antepartum and postpartum LMWH prophylaxis in women with a known thrombophilia or prior VTE. Advice for the management of LMWH prophylaxis use around labor and delivery is also reviewed.

A case that illustrates the challenges of managing pregnant patients with antithrombin deficiency: More questions than answers

Using an illustrative case of a patient with antithrombin (AT) deficiency who developed a recurrent venous thromboembolism (VTE) in pregnancy despite therapeutic low-molecular-weight heparin (LMWH), we highlight what is known in the literature and address areas of controversy through a series of questions around the case. The questions we address include the role of anti-Xa monitoring for patients with past VTE on antepartum LMWH, what treatment regimen is recommended for pregnant patients who develop a recurrent VTE while on therapeutic anticoagulation, the role of antepartum AT concentrate prophylaxis, and the management of labor/delivery, epidural anesthesia and postpartum anticoagulation. We also describe practical considerations for use of AT concentrate, including teaching our patient to self-infuse AT concentrate at home with support of a hemophilia treatment center (HTC), and the direct and indirect costs of AT concentrate for secondary prophylaxis.