Evaluation of therapeutic efficacy of anticoagulant drugs for patients with venous thromboembolism during pregnancy: A systematic review and meta-analysis

Diagnosis and treatment of venous thromboembolism during pregnancy relate to genetic polymorphism

OBJECTIVES

Previous research had shown that age, a positive family history, comorbidities, major surgical operations, gestation, and use of several medications could increase the incidence of venous thromboembolism (VTE). With the development of medical and clinical individualized treatment, many people exposed to above risk factors did not develop VTE, suggested that genetic factors are also involved in the development of VTE. In this review, we aim to summarize VTE diagnosis and treatment in pregnancy women related to gene polymorphism.

METHODS

A comprehensive electronic search using PubMed, MEDLINE, EMBASE and Web of Science was conducted to find relevant journal articles with key search terms including: "pregnancy OR pregnant," "venous thromboembolism OR VTE," "deep vein thrombosis OR DVT," "pulmonary embolism OR PE," and "genetic OR gene." Prominent publications from establishment of database till present were analysed to achieve a deeper understanding of VTE during pregnancy relate to genetic polymorphism, and the information was then collated to form this review.

RESULTS

The literature review revealed that inherited thrombophilia significantly associated with the development of VTE, especially the factor V Leiden (FVL) and prothrombin gene mutation (PGM). Furthermore, the role of methylenetetrahydrofolate reductase (MTHFR) gene mutation in the development of pregnancy-related VTE remains controversial, further study is required. In the present study, Marburg I polymorphism (G511 E), c.1538 G>A and c.1601 G>A in Factor V (FV), JAK2V617 F mutation were reported as an independent risk factor for VTE, there is no sufficient evidence to confirm the gene mutation is related to VTE during pregnancy, these factors appearing as another promising potential diagnostic marker of VTE during pregnancy. Besides, the dosages of heparin in the treatment of VTE during pregnancy need be adjusted according to gene polymorphism of these population, particularly FVL or PGM carriers, and this area is not studied deeply, it is worth further study.

CONCLUSION

Inherited thrombophilia significantly associated with the development of VTE, especially the FVL and PGM, however the relation between MTHFR gene mutation and pregnancy-related VTE remains controversial, further study is needed. In addition, the dosages of heparin in the treatment of VTE during pregnancy suggested to adjusted based on gene polymorphism in FVL and PGM, and establish better prediction models is a direction of future research.

Anticoagulation for mechanical heart valves during pregnancy: A case report and a literature review

RATIONALE

Most previous treatment guidelines for pregnant women with mechanical heart valves recommend that low molecular weight heparin (LMWH) should be applied once every 12 hours and only as required to reach peak anti-Xa levels of approximately 1.0 to 1.2 IU/mL, but it is commonly associated with subtherapeutic trough levels, consequently with an inadequate level of anticoagulation. Our case report here together with a literature review suggests that dose-adjusted (Target trough anti-Xa levels of 0.6 to 0.7 IU/mL and with peak anti-Xa levels of around 1.0 to 1.2 IU/mL or < 1.5 IU/mL) LMWH should be given thrice daily throughout pregnancy. In addition, the findings of this rare case indicate that a combination of LMWH and warfarin is effective in the treatment of small thromboses in pregnancy.

PATIENT CONCERNS

In the 1st trimester of pregnancy, a 28-year old pregnant female with a mechanical valve had a significant increase in the aortic valve flow rate and suspected mechanical valve thrombosis.

DIAGNOSES

The peak velocity of the pregnant female aortic mechanical valve increased, and mechanical valve thrombosis was suspected.

INTERVENTIONS

We adjusted the enoxaparin sodium dose every 12 hours to 1 injection every 8 hours, with a total daily dose of 160 mL. Based on the original application of LMWH, warfarin (3 mg/day) was recommended.

OUTCOMES

The pregnant woman delivered a live baby by cesarean section, and the peak flow velocity of the mechanical valve in the aortic position was reduced to nearly equivalent to the patient's pre-pregnancy status. The mother and the baby were in good health at the time of discharge.

LESSONS

LMWH is administered twice daily, and anti-Xa trough levels are mostly in a subtherapeutic state, which may lead to insufficient anticoagulation and thrombosis. Dose-adjusted LMWH thrice daily throughout pregnancy is the recommended treatment for pregnant women with mechanical heart valves. The combination of LMWH and warfarin exhibited good efficacy for the treatment of small thromboses.

Bleeding in women with venous thromboembolism during pregnancy: A systematic review of the literature

Objectives

Venous thromboembolism (VTE) represents an important cause of maternal morbidity and mortality. Estimates of bleeding associated with therapeutic‐dose anticoagulation are variable. We describe the frequency of bleeding in pregnant women receiving therapeutic anticoagulation for VTE by means of a systematic review of the literature.

Data Sources

Medical Literature Analysis and Retrieval System, Embase, Scopus, Web of Science, and ClinicalTrials.gov were searched. Databases were searched from inception to February 27, 2022. There was no language or geographic location restriction.

Methods of Study Selection

The search yielded 2773 articles with 2212 unique citations. Studies were included if they described pregnant women treated for an acute VTE with therapeutic‐dose anticoagulation and a defined bleeding outcome was reported.

Tabulation, Integration, and Results

Five studies met inclusion criteria. Included studies were judged to have a serious to critical risk of bias using the Risk of Bias in Nonrandomized Studies of Intervention tool. The rate of bleeding, as defined by respective studies, ranged between 2.9% and 30.0%. Two studies included control groups, one of which found no significant difference in the risk of bleeding between groups, while the other found a significantly increased bleeding risk associated with therapeutic anticoagulation.

Conclusion

Among pregnant women anticoagulated for VTE, the reported bleeding risk is variable. The ability to draw definite conclusions is limited by the scarcity and low quality of the studies, the small number of included patients, and the heterogeneity of bleeding definitions used. Large‐scale studies with standardized bleeding definitions are required to provide acute bleeding estimates and optimize the care of these patients.

Systematic Review Registration

PROSPERO, CRD42021276771.

Management of anticoagulation in pregnant women with venous thromboembolism: An international survey of clinical practice

INTRODUCTION

Venous thromboembolism (VTE) is an important cause of maternal morbidity and mortality. During pregnancy, VTE is treated with low-molecular-weight-heparin (LMWH). Studies assessing the optimal duration and peripartum management of therapeutic anticoagulation are lacking. This survey aimed to assess clinician practices for the management of anticoagulation in pregnant women with acute VTE.

METHODS

An electronic survey consisting of clinical scenarios addressing anticoagulation management for VTE in pregnancy was created. The target sample was clinicians likely to be involved in the management of pregnant women with acute VTE. The survey completion rate and proportion of individuals selecting a response were determined.

RESULTS

96 respondents completed the survey including general internists (56.3%), hematologists (21.9%), and obstetricians (6.3%). In the management of a VTE in first or second trimester, most respondents preferred therapeutic LMWH until 6 weeks postpartum. In the first and second trimester, 48.0% and 37.5% of respondents, respectively, opted to reduce the dose of anticoagulation after 3 or 6 months. 29.2% of physicians opted for bridging with intravenous heparin around delivery when treating a VTE in the third trimester. 73.0% perceived an increased risk of clinically relevant non-major bleeding associated with the use of therapeutic anticoagulation in the peripartum and postpartum periods.

CONCLUSIONS

The survey highlights a wide variability of practice in the management of therapeutic anticoagulation in pregnancy. Larger scale studies with relevant clinical outcomes including thrombosis and bleeding risks are needed to inform clinical practice.

Assessing the Impact on Health of Pharmacovigilance Activities: Example of Four Safety Signals

INTRODUCTION

The impact of pharmacovigilance activities on public health remains under-investigated, and measuring the impact on health of pharmacovigilance activities for a specific safety signal is challenging.

OBJECTIVE

To gain more insight into the methodological challenges and the data required, we assessed the impact of pharmacovigilance on public health for four identified product-specific safety signals using publicly available data in the Netherlands. The assessment was on the impact of the intertwined and complementary steps of the pharmacovigilance pathways.

METHODS

The impact of pharmacovigilance on public health was assessed using the assessment support tool and 'open data' from the Netherlands for four different types of pharmacovigilance safety signals: (1) off-label use of cyproterone acetate/ethinyloestradiol (CPA/EE) and thrombotic risk after pharmacovigilance measures after 2014; (2) pergolide and the risk of cardiac valvulopathy after pharmacovigilance activities in 2003; (3) proton pump inhibitors and the risk of hypomagnesaemia after pharmacovigilance activities in 2011; (4) rosiglitazone withdrawal from the market because of cardiovascular effects in 2010.

RESULTS

For the signals on CPA/EE and pergolide, a crude estimation of the impact could be made with varying degrees of assumptions based on the risk described in the literature and utilisation data.

CONCLUSION

This article highlights the methodological challenges and the data required to assess the impact of product-specific safety signals. A structured assessment support tool can be used as a guide for the necessary data elements and steps needed for the measurement or estimation of impact of pharmacovigilance activities on public health, provided that the appropriate data are available.

In vitro renal toxicity evaluation of copper-based metal-organic framework HKUST-1 on human embryonic kidney cells

HKUST-1 is currently studied for a very diverse range of applications. Despite its exciting potential, significant concerns remain regarding the safety of HKUST-1. Therefore, human embryonic kidney 293 (HEK293) cells were used to verify the renal toxicity of HKUST-1. In this study, HKUST-1 induced concentration-dependent cytotoxic effects in HEK293 cells. The depolarization of mitochondrial membrane potential and formation of apoptotic bodies and autophagic vesicles were observed in HKUST-1-treated HEK293 cells. Oxidative (oxidative stress and haem oxygenase-1 activation) and inflammatory responses (NF-κB and NLRP3 activation) in HEK293 cells were induced by HKUST-1 exposure. In addition, the observed reduction in NAD(P)H levels in HKUST-1-treated HEK293 cells may be attributable to PARP-1 activation following DNA single- and double-strand breaks. The HKUST-1-induced depletion of zonula occludens proteins in HEK293 cells might lead to altered renal barrier integrity. The variations of α1-antitrypsin, oxidised α1-antitrypsin and NLRP3 protein expression in HEK293 cells suggested that HKUST-1 increases the risk of chronic kidney diseases. However, most of these adverse effects were significantly induced only by high HKUST-1 concentration (100 μg/mL), which do not reflect the actual exposure. Thus, the toxic risk of HKUST-1 appears to be negligible.

Current Resources for Evidence-Based Practice, May 2020

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of a new National Academy of Medicine report on planned place of birth and implications during the SARS-CoV-2 pandemic and commentaries on reviews focused on anorectal sexually transmitted infections and feeding methods following cleft lip repair in infants.