Diagnosis and management of heritable thrombophilias

Thrombophilia Screening: Not So Straightforward

Although inherited thrombophilias are lifelong risk factors for a first thrombotic episode, progression to thrombosis is multifactorial and not all individuals with inherited thrombophilia develop thrombosis in their lifetimes. Consequently, indiscriminate screening in patients with idiopathic thrombosis is not recommended, since presence of a thrombophilia does not necessarily predict recurrence or influence management, and testing should be selective. It follows that a decision to undertake laboratory detection of thrombophilia should be aligned with a concerted effort to identify any significant abnormalities, because it will inform patient management. Deficiencies of antithrombin and protein C are rare and usually determined using phenotypic assays assessing biological activities, whereas protein S deficiency (also rare) is commonly detected with antigenic assays for the free form of protein S since available activity assays are considered to lack specificity. In each case, no single phenotypic assay is capable of detecting every deficiency, because the various mutations express different molecular characteristics, rendering thrombophilia screening repertoires employing one assay per potential deficiency, of limited effectiveness. Activated protein C resistance (APCR) is more common than discrete deficiencies of antithrombin, protein C, and protein S and also often detected initially with phenotypic assays; however, some centres perform only genetic analysis for factor V Leiden, as this is responsible for most cases of hereditary APCR, accepting that acquired APCR and rare F5 mutations conferring APCR will go undetected if only factor V Leiden is evaluated. All phenotypic assays have interferences and limitations, which must be factored into decisions about if, and when, to test, and be given consideration in the laboratory during assay performance and interpretation. This review looks in detail at performance and limitations of routine phenotypic thrombophilia assays.

Cerebral infarction and in-hospital mortality for patients admitted to hospital with intracardiac thrombus: insights from the National Inpatient Sample

The factors associated with cerebral infarction and mortality in patients hospitalized with intracardiac thrombus are unknown. A retrospective cohort study was undertaken of nationally representative hospital admissions in the National Inpatient Sample with a diagnosis of intracardiac thrombus between 2016 to 2019. Multiple logistic regressions were used to define factors associated with cerebral infarction and in-hospital mortality. There were a total of 175,370 admissions for patients with intracardiac thrombus and 10.1% patients had cerebral infarction (n = 17,675). Intracardiac thrombus represented 4.4% of primary diagnosis for admissions while circulatory conditions (65.4%), infection (5.9%), gastrointestinal conditions (4.4%), respiratory conditions (4.4%) and cancer (2.2%) were the other prevalent primary diagnoses. All-cause mortality was higher for patients with cerebral infarction (8.5% vs 4.8%). The five factors most associated with cerebral infarction were nephrotic syndrome (OR 2.67 95%CI 1.05-6.78), other thrombophilia (OR 2.12 95%CI 1.52-2.95), primary thrombophilia (OR 1.99 95%CI 1.52-2.53), previous stroke (OR 1.61 95%CI 1.47-1.75) and hypertension (OR 1.41 95%CI 1.27-1.56). The strongest independent predictors of death were heparin induced thrombocytopenia (OR 2.45 95%CI 150-4.00), acute venous thromboembolism (OR 2.03 95%CI 1.78-2.33, p < 0.001) acute myocardial infarction (OR 1.95 95%CI 1.72-2.22), arterial thrombosis (OR 1.75 95%CI 1.39-2.20) and cancer (OR 1.57 95%CI 1.36-1.81). Patients with intracardiac thrombus are at risk of cerebral infarction and in-hospital mortality. Nephrotic syndrome, thrombophilia, previous stroke, hypertension, and heparin induced thrombocytopenia were associated with cerebral infarction, while acute venous thromboembolism, acute myocardial infarction, and cancer were predictors of mortality.

Assessment of the Particularities of Thrombophilia in the Management of Pregnant Women in the Western Part of Romania

Background and objectives: Thrombophilia in pregnant women is a condition whose incidence is constantly increasing worldwide, and, under these conditions, the development of preventive procedures is becoming essential. In this study, we aimed to evaluate thrombophilia in pregnant women in the western part of Romania and to establish anthropometric characteristics, socioeconomic features, and genetic and risk factors. Material and Methods: 178 pregnant women were divided into three study groups, according to the type of thrombophilia, aiming to carry out the genetic profile and the acquired one. Anthropometric measures and biological tests were performed. Results: The mixed type of thrombophilia predominates. The particularities of pregnant women diagnosed with thrombophilia are higher age, living in an urban environment, with normal BMI, approximately 36 weeks of gestational period, and having at least one miscarriage. Regarding the most frequent thrombophilic genetic markers, we obtained the MTFHR gene mutation C677T and A1298C, followed by the PAI-1 4G/5G gene mutation. Smoking represents an aggravating factor in the evolution of this pathology, manifested through the increase of D-dimers and the decrease in antithrombin values, simultaneously with the increase in therapeutic need. Conclusions: The predominance of MTHFR and PAI-1 4G/5G gene polymorphism is a particularity of pregnant women with thrombophilia from the western part of Romania. Smoking is confirmed as an important risk factor in spontaneous abortion.

Pathophysiological, immunogenetic, anatomopathological profile of thrombophilia in pregnancy

Thrombophilic states have been associated with early and/or late pregnancy loss and possibly other severe obstetrical complications. Pregnancy-induced hypercoagulability, increased stasis, and the consequences of inherited and acquired thrombophilia are just a few of the factors that contribute to the development of thrombosis in pregnancy. In this review, we illustrate the impact that these factors have on the development of thrombophilia during pregnancy. We also explore how thrombophilia impact pregnancy outcomes. Next, we discuss how human leukocyte antigen G plays a part in thrombophilia during pregnancy by regulating cytokine release to prevent trophoblastic cell invasion and maintain local immunotolerance constant. Human leukocyte antigen class E is briefly explored with thrombophilia in pregnancy. Regarding the anatomopathologic aspect, we describe the different histopathological lesions of the placenta found in women with thrombophilia.

An Atypical Case of Idiopathic Purpura Fulminans

Idiopathic purpura fulminans (PF) is rare but has been reported in pediatric patients, commonly following infections. We present a case of a 5-year-old boy, heterozygous for factor V Leiden, with no history of recent infections, who presented with PF secondary to acquired protein S deficiency. Despite initial supportive treatment, the patient required surgical fasciotomy and extensive skin grafts. The protein S level normalized 4 months following the presentation. In this context, an autoimmune component with transient anti-protein S antibodies was believed to be involved. This case report highlights the course of idiopathic PF due to noninfectious acquired protein S deficiency.

Evolving Knowledge on Primary and Secondary Prevention of Venous Thromboembolism in Carriers of Hereditary Thrombophilia: A Narrative Review

The association between heritability of venous thromboembolism (VTE) and thrombophilia was first reported clinically in 1956, later followed by the first description of a congenital cause of hypercoagulability-antithrombin deficiency-in 1965. Since then, our knowledge of hereditary causes of hypercoagulability, which may predispose carriers to VTE has improved greatly. Novel genetic defects responsible for severe thrombophilia have been recently identified and we have learned that a wide range of interactions between thrombophilia and other genetic and acquired risk factors are important determinants of the overall individual risk of developing VTE. Furthermore, therapeutic strategies in thrombophilic patients have benefited significantly from the introduction of direct oral anticoagulants. The present review is an overview of the current knowledge on the mechanisms underlying inherited thrombophilia, with a particular focus on the latest achievements in anticoagulation protocols and prevention strategies for thrombosis in carriers of this prothrombotic condition.

Evolving Knowledge on Primary and Secondary Prevention of Venous Thromboembolism in Carriers of Hereditary Thrombophilia: A Narrative Review

The association between heritability of venous thromboembolism (VTE) and thrombophilia was first reported clinically in 1956, later followed by the first description of a congenital cause of hypercoagulability-antithrombin deficiency-in 1965. Since then, our knowledge of hereditary causes of hypercoagulability, which may predispose carriers to VTE has improved greatly. Novel genetic defects responsible for severe thrombophilia have been recently identified and we have learned that a wide range of interactions between thrombophilia and other genetic and acquired risk factors are important determinants of the overall individual risk of developing VTE. Furthermore, therapeutic strategies in thrombophilic patients have benefited significantly from the introduction of direct oral anticoagulants. The present review is an overview of the current knowledge on the mechanisms underlying inherited thrombophilia, with a particular focus on the latest achievements in anticoagulation protocols and prevention strategies for thrombosis in carriers of this prothrombotic condition.

Low molecular weight heparin and pregnancy outcomes in women with inherited thrombophilia: A systematic review and meta-analysis

AIM

To determine whether the use of low molecular weight heparin (LMWH) improves the pregnancy outcomes in women with inherited thrombophilia by conducting a meta-analysis of randomized controlled trials and observational studies.

METHODS

A systematic literature search of several databases was conducted through September 19, 2020 to identify relevant studies. The outcomes of interest included live birth and adverse pregnancy outcomes (APOs). The overall risk estimates were pooled using random-effects meta-analysis.

RESULTS

Ten randomized controlled trials and 12 cohort studies were included. In the meta-analyses of randomized controlled trials, the effectiveness of LMWH-treatment was found to be statistically significant in decreasing the risk of APOs (risk ratio [RR] = 0.76; 95% confidence interval [CI]: 0.61-0.95; p = 0.020), rather than in increasing the rate of live birth (RR = 1.12; 95% CI: 0.93-1.34; p = 0.230). In the meta-analyses of cohort studies, results showed that the use of LMWH was associated with a significantly higher proportion of live birth (RR = 1.86; 95% CI: 1.09-3.19; p = 0.020) as well as a significantly lower ratio of APOs (RR = 0.46; 95% CI: 0.31-0.69; p < 0.001) in women with inherited thrombophilia.

CONCLUSIONS

The use of LMWH may have a potentially beneficial effect on reducing the risk of APOs and even increasing the live birth rate in women with inherited thrombophilia. Further well-designed clinical trials with large samples are needed to address the role of LMWH in improving pregnancy outcomes among pregnant women with inherited thrombophilia.

Approach to Thrombophilia in Pregnancy-A Narrative Review

Thrombophilia is a genetic predisposition to hypercoagulable states caused by acquired haemostasis conditions; pregnancy causes the haemostatic system to become hypercoagulable, which grows throughout the pregnancy and peaks around delivery. Genetic testing for thrombophilic gene mutations is evaluated using different methodologies of real-time polymerase chain reaction and DNA microarrays of specific genes. Adapting the general care of the pregnant woman to the particularities caused by thrombophilia is an important component, so screening is preferred to assess the degree of genetic damage that manifests itself as a risk of thrombosis. The major goal of this narrative review was to quantitatively evaluate the literature data on the specific care of pregnant women with thrombophilia that are at risk of developing unplanned miscarriages.

Patients with SERPINC1 rs2227589 polymorphism found to have multiple cerebral venous sinus thromboses despite a normal antithrombin level: A case report

BACKGROUND

The hereditary antithrombin (AT) deficiency caused by SERPINC1 gene mutation is an autosomal dominant thrombotic disorder. An increasing number of studies have shown that mutations in the SERPINC1 rs2227589 polymorphic site are correlated with a risk of venous thromboembolism (VTE) at common sites, such as lower extremity deep venous thrombosis and pulmonary thromboembolism. Currently, there are no reports of cerebral venous sinus thrombosis (CVST), a VTE site with a low incidence rate and rs2227589 polymorphism.

CASE SUMMARY

Here, we report a Chinese CVST case with a mutation of the SERPINC1 rs2227589 polymorphic site, which did not cause significant AT deficiency. In a 50-year-old male patient presenting with multiple cerebral venous sinus thromboses no predisposing factors were detected, although a relative had a history of lower extremity deep venous thrombosis. We performed sequencing of the SERPINC1 gene for the patient and his daughter, which revealed the same heterozygous mutation at the rs2227589 polymorphic site: c.41+141G>A.

CONCLUSION

The results showed that more studies should be conducted to assess the correlation between rs2227589 polymorphism and CVST.

Hypercoagulable Disorders in Orthopaedics: Etiology, Considerations, and Management

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Hypercoagulable disorders (HCDs) can be inherited or acquired. An HCD of either etiology increases the chance of venous thromboembolic events (VTEs).

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Patients with an HCD often have the condition discovered only after surgical complications.

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We recommend that patients with a concern for or a known HCD be referred to the appropriate hematological specialist for workup and treatment.

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Tourniquet use in the orthopaedic patient with an HCD is understudied and controversial. We recommend that tourniquets be avoided in the surgical management of patients with an HCD, if possible. When tourniquets are applied to patients with unknown HCD status, close follow-up and vigilant postoperative examinations should be undertaken.

Venous Thromboembolism in ICU Patients with Intracerebral Hemorrhage: Risk Factors and the Prognosis After Anticoagulation Therapy

Purpose

Venous thromboembolism (VTE) is a common complication of intracerebral hemorrhage (ICH) patients in intensive care unit (ICU), but anticoagulation therapy of ICH patients with VTE remains controversial. We aim to explore the risk factors and prognosis of anticoagulation therapy in ICH patients with VTE.

Patients and Methods

Medical records of ICH patients were collected from the Medical Information Mart for Intensive Care III (MIMIC-III version 1.4) database. The risk factors and prognosis of anticoagulation therapy in ICH patients with VTE were assessed by multivariable logistic regression analysis and Kaplan–Meier survival analysis, respectively.

Results

A total of 848 ICH patients were included in our study, of whom 69 ICH patients with VTE were screened, including 58 patients with deep vein thrombosis (DVT), 12 patients with pulmonary embolism (PE), and 1 patient with DVT and PE. In the multivariable logistic regression analysis, malignancy (odds ratio (OR): 4.262, 95% confidence interval (CI): 2.263–8.027, P=0.000), pulmonary circulation disease (OR: 28.717, 95% CI: 9.566–86.208, P=0.000), coagulopathy (OR: 2.453, 95% CI: 1.098–5.483, P=0.029), age > 60 years old (OR: 2.138, 95% CI: 1.087–4.207, P=0.028) and hospitalization time > 16 days (OR: 2.548, 95% CI: 1.381–4.701, P=0.003) were independent risk factors for VTE in ICH patients. Kaplan–Meier survival analysis and log-rank test found that, compared to non-anticoagulation group, anticoagulation group had higher cumulative survival rates during hospitalization, 28-day, 3-month, 1-year, and 4-year after admission, respectively.

Conclusion

Malignancy, pulmonary circulation disease, coagulopathy, age >60 years old and hospitalization time >16 days were independent risk factors for VTE in ICH patients, and anticoagulation therapy for VTE in ICH patients may be safe and effective. These findings need to be verified by more high-quality and well-designed randomized controlled trials.

Hereditary thrombophilia and recurrent pregnancy loss: a systematic review and meta-analysis

STUDY QUESTION

Is there an association between hereditary thrombophilia in pregnant women and risk of recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

Pregnant women with hereditary thrombophilia have an increased risk of RPL, especially for pregnant women with the G1691A mutation of the factor V Leiden (FVL) gene, the G20210A mutation of the prothrombin gene (PGM), and deficiency of protein S (PS).

WHAT IS KNOWN ALREADY

Prior studies have suggested that pregnant women with hereditary thrombophilia have a higher risk of RPL, however, the results are inconsistent; furthermore, a complete overview is missing. This lack of information is an obstacle to the risk assessment of RPL in pregnant women with hereditary thrombophilia. A comprehensive meta-analysis on the relation between hereditary thrombophilia and the risk of RPL is needed.

STUDY DESIGN, SIZE, DURATION

A systematic review and meta-analysis was performed using observational studies published in English before 1 April 2020 to evaluate the relation between hereditary thrombophilia and risk of RPL.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Relevant studies were identified from PubMed, Web of Science, and EMBASE searches and complemented with perusal of bibliographies of retrieved articles. The exposure of interest was hereditary thrombophilia, including FVL mutation, PGM, deficiency of antithrombin (AT), deficiency of protein C (PC), and deficiency of PS. The overall risk estimates were pooled using random effects models. Subgroup and sensitivity analyses were carried out to explore possible sources of heterogeneity and assess the robustness of the results.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 89 studies involving 30 254 individuals were included. Results showed that women with FVL mutation (odds ratio (OR): 2.44, 95% CI: 1.96-3.03), PGM (OR: 2.08, 95% CI: 1.61-2.68), or deficiency of PS (OR: 3.45, 95% CI: 1.15-10.35) had higher risks of developing RPL. Compared with the reference group, there was no observed relation between a deficiency in AT or PC and RPL (all P > 0.05). Heterogeneity in the risk estimates of RPL was partially explained by geographic region, definitions of RPL, types of RPL, and controlled confounders. Sensitivity analyses validated the robustness of the findings.

LIMITATIONS, REASONS FOR CAUTION

Only 39 of the included studies controlled for one or more confounders, and the heterogeneity across all included studies was high. Based on the data available, we cannot determine whether this association is confounded by other potential risk factors of RPL.

WIDER IMPLICATIONS OF THE FINDINGS

This systematic review and meta-analysis show a possible association between hereditary thrombophilia and an increased risk of RPL, suggesting that testing for hereditary thrombophilia should be considered in individuals with RPL.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Hunan Provincial Key Research and Development Program (Grant number: 2018SK2062) and National Natural Science Foundation Program (Grant number: 81973137). There are no conflicts of interest.

REGISTRATION NUMBER

N/A.

Simultaneous intracoronary, intracardiac, and pulmonary venous thrombosis

Arterial and venous thromboses are very prevalent diseases and it has been discovered that they share some common pathways, but their presentation in young patients is rare and should raise concern for thrombophilia. Therefore, the case is presented of a 34 year-old female with no prior pertinent history and with no predisposing factors. She was diagnosed with a pulmonary embolism, with an incidental finding of a left ventricular thrombus. A coronary artery thrombosis was also found. The patient met the criteria for a thrombophilia work-up, but the authors would like to express their concern on whether these tests are truly necessary, as they would not have change the patient management.

Heritable thrombophilia test utilization and cost savings following guideline-based restrictions: An interrupted time series analysis

OBJECTIVE

Existing guidelines provide indications for appropriate heritable thrombophilia (HT) testing but testing practices often do not conform to these guidelines. The Canadian province of Newfoundland and Labrador (NL) implemented a new 'hard-stop' guideline-based approach to HT testing whereby tests ordered outside specific guidelines were rejected. The objective of this study was to evaluate the effectiveness of this intervention and the associated cost savings.

METHODS

Using data on number of HT tests ordered and performed in NL between December 1, 2014 and February 28, 2018, we conducted interrupted time series analyses to analyze changes in number of HT tests ordered and performed following the intervention. Cost savings were estimated by comparing cost of tests actually performed after enforcement of guidelines with the cost of counterfactual number of tests that would have been performed without guidelines.

RESULTS

Guideline-based restrictions on HT testing were associated with a 86-98% decline in the number of tests performed (p < 0.05). Contrary to previous softer, educational approaches to restricting HT testing, number of Protein C and Factor V Leiden/Prothrombin G20210A tests ordered also declined post-guideline implementation (p < 0.05). Annual cost savings associated with reductions in tests performed were estimated to be $205,154 for NL from a societal perspective. We estimated that if this model was expanded across Canada, annual cost savings could be as large as $14.2 million from a societal perspective.

CONCLUSIONS

A 'hard-stop' guideline-based approach to restricting HT testing is associated with significant reductions in HT testing and meaningful cost savings.

A multicenter study of thromboembolic events among patients diagnosed with ROS1-rearranged non-small cell lung cancer

OBJECTIVES

This study aimed to describe the longitudinal thromboembolism (TE) risk relative to the natural history of disease and clinical course of ROS1 rearranged non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Cases of ROS1-rearranged NSCLC from six Australian hospitals were pooled and evaluated for incidence, timing, predictors and outcomes of venous or arterial TE, as well as objective response rate (ORR) to active therapy and overall survival (OS).

RESULTS

Of 42 patients recruited, 20 (48%) experienced TE; one (2%) arterial, 13 (31%) a pulmonary emboli (PE), and 12 (29%) a deep vein thrombosis. Among those with TE, six (30%) experienced multiple events, three as concurrent and three as recurrent diagnoses. The cumulative incidence of TE over time, adjusted for death as a competing risk factor, approached 50%. TE occurred prior to, during and post the peri-diagnostic period and occurred irrespective of treatment strategy. A thrombophilia was identified in n = 3/10 (30%) cases screened: in two factor V Leiden and in one anti-thrombin III (ATIII) deficiency. Median OS was 21.3 months in those with TE vs. 28.8 months in those without; hazard ratio 1.16 (95%CI 0.43-3.15). Respective ORR to first-line therapy with TE was 50% vs. 44% without TE in the chemotherapy arm and 67% vs. 50% in the targeted therapy arm.

CONCLUSION

In the rare cancer subtype, ROS1, these real-world data demonstrate sustained TE risk beyond the diagnostic period irrespective of therapeutic strategy. High incidence of PE, concurrent TE, and recurrent TE warrant validation in larger cohorts. Consideration of primary thromboprophylaxis in ROS1 populations is recommended.

EANM guideline for ventilation/perfusion single-photon emission computed tomography (SPECT) for diagnosis of pulmonary embolism and beyond

These guidelines update the previous EANM 2009 guidelines on the diagnosis of pulmonary embolism (PE). Relevant new aspects are related to (a) quantification of PE and other ventilation/perfusion defects; (b) follow-up of patients with PE; (c) chronic PE; and (d) description of additional pulmonary physiological changes leading to diagnoses of left ventricular heart failure (HF), chronic obstructive pulmonary disease (COPD) and pneumonia. The diagnosis of PE should be reported when a mismatch of one segment or two subsegments is found. For ventilation, Technegas or krypton gas is preferred over diethylene triamine pentaacetic acid (DTPA) in patients with COPD. Tomographic imaging with V/PSPECT has higher sensitivity and specificity for PE compared with planar imaging. Absence of contraindications makes V/PSPECT an essential method for the diagnosis of PE. When V/PSPECT is combined with a low-dose CT, the specificity of the test can be further improved, especially in patients with other lung diseases. Pitfalls in V/PSPECT interpretation are discussed. In conclusion, V/PSPECT is strongly recommended as it accurately establishes the diagnosis of PE even in the presence of diseases like COPD, HF and pneumonia and has no contraindications.

Overcoming challenges of venous thromboembolism in sickle cell disease treatment

INTRODUCTION

Venous thromboembolism (VTE) is a common comorbid condition found in sickle cell disease (SCD) and is associated with increased mortality for adults with SCD. The pathophysiology that leads to the thrombophilic state in SCD has been previously reviewed; however, evidence-based guidelines to aid in diagnosis, prevention, and management of VTE are lacking. Areas covered: This review article will cover the pathophysiology underlying the hypercoagulable state, the epidemiology of VTE, and management strategies of VTE in SCD. Expert opinion: Providers should have a high suspicion for diagnosing VTE to help reduce morbidity and mortality in the SCD population. Unlike other thrombophilias, the risk of life-threatening anemia while being treated with anticoagulation is compounded with the potential complications surrounding red blood cell transfusions in this population (i.e. alloimmunization, hyperhemolysis) and this provides another complexity to managing VTE in this population. Clinical trials evaluating the risk and benefit of treatment and treatment duration are needed.

Thrombophilia, risk factors and prevention

INTRODUCTION

Fifty-three years after the first description of an inherited prothrombotic condition (antithrombin deficiency), our knowledge on hereditary and acquired causes of hypercoagulability that can predispose carriers to venous thromboembolism (VTE) has greatly improved. Areas covered: Main causes of hereditary thrombophilia are summarized alongside new prothrombotic mutations recently discovered. The main causes of acquired thrombophilia, and namely, antiphospholipid antibody syndrome and hyperhomocysteinemia, are also discussed together with other common acquired prothrombotic states characterized by an increase of procoagulant factors and/or a decrease of natural anticoagulants. Finally, suggestions for thromboprophylaxis in carriers of hereditary thrombophilia according to current guidelines/evidence are made for the most challenging high-risk situations (i.e. surgery, pregnancy, contraception, cancer, economy class syndrome) as well as for the prevention of post-thrombotic syndrome. Expert opinion: A carrier of inherited thrombophilia should be evaluated in the framework of other (genetic and/or acquired) coexisting risk factors for first or recurrent VTE when assessing the need and duration of prevention (primary prophylaxis). Prevention strategies should be tailored to each patient and every situational risk factor. The knowledge of the carriership status of severe thrombophilia in the proband can be important to provide asymptomatic relatives with adequate counseling on thrombophilia screening or primary thromboprophylaxis.

[Risk factors for thromboembolic disease in young women-the role of hormones]

Hormonal exposure in young women increases the risk of venous thromboembolic disease (VTE). Thrombophilia testing is often proposed in women of childbearing age before the initiation of contraception. However, the presence of a familial history of VTE has the potential to be more accurate than the presence of inherited thrombophilia.

OBJECTIVE

To demonstrate an association between the risk of VTE in young women with hormonal exposure (pregnancy or oral contraceptive use) and the presence of a previous episode of VTE in their first-degree relatives, according to whether or not a detectable inherited thrombophilia was present.

METHODS

We will perform a multicenter case-control cross-sectional study. The main risk factor is defined by the presence of a symptomatic VTE in young women with hormonal exposure. The principle variable is the presence of an objectively diagnosed episode of VTE in first-degree relatives. We will need to include 2,200 family members in 440 cases.

EXPECTED RESULTS

We expect to improve understanding of the thrombotic risk in first-degree relatives of patients in hormonal context with or without a past history of VTE.

Non-O blood group and outcomes of in vitro fertilization

PURPOSE

Retrospective and cross-sectional studies suggested that non-O blood group may be associated with failures of in vitro fertilization (IVF), but data remain controversial. The aim of this observational cohort study was to prospectively evaluate the effect of non-O blood type on clinical outcomes of IVF.

METHODS

Women < 40 years who underwent IVF and had ABO blood type recorded as part of the routine workup were eligible. The primary study outcome was live birth. Secondary outcomes included spontaneous abortion, positive pregnancy test, and clinical pregnancy.

RESULTS

A total of 497 women with a mean age of 34.6 (standard deviation 3.2) years were included. The mean number of embryos transferred was 2.3 (standard deviation 0.6). The most common ABO blood types were O (n = 213, 42.9%) and A (n = 203, 40.8%), while 63 (12.7%) and 18 (3.6%) women had the B and AB blood types, respectively. Differences in live birth (21.8 vs. 24.3%, odds ratio [OR] 1.17; 95% confidence intervals [CI], 0.76 to 1.78), positive pregnancy test (37.9 vs. 36.6%, OR 0.96; 95% CI, 0.66 to 1.38), clinical pregnancy (35.1 vs. 33.8%, OR 0.95; 95% CI, 0.66 to 1.39), and spontaneous abortion (12.3 vs. 9.2%, OR 0.72; 95% CI, 0.41 to 1.29) between women with O and non-O blood type were not statistically significant.

CONCLUSIONS

In a prospective cohort study, we confirmed the lack of a significant association between non-O blood type and clinical outcomes of IVF. Further studies are needed to clarify whether non-O blood group has any prognostic relevance in women undergoing IVF.

Successful medical management of acute mesenteric ischemia due to superior mesenteric and portal vein thrombosis in a 27-year-old man with protein S deficiency: a case report

Background

Acute mesenteric ischemia poses a diagnostic challenge due to nonspecific clinical clues and lack of awareness owing to its rarity. Ischemia due to mesenteric venous thrombosis has a good prognosis compared to arterial cause and can be managed conservatively with early diagnosis. The portomesenteric venous system is an unusual site of thrombosis in patients with protein S deficiency, and its thrombosis is an uncommon cause of acute mesenteric ischemia.

Case presentation

We present a case of a 27-year-old Mongolian man who presented with acute abdominal pain increasing in severity, and refractory to repeated attempts at treatment with a misdiagnosis of acute peptic ulcer disease. Contrast-enhanced computed tomography of his abdomen detected complete occlusion of the superior mesenteric vein, an extension of acute thrombus into the portal vein, and ischemic mid-jejunal loops. Early diagnosis and immediate anticoagulation with continuous intravenous infusion of unfractionated heparin prevented subsequent consequences. On further workup, our patient was diagnosed with isolated protein S deficiency. We started lifelong thromboprophylaxis with warfarin to prevent recurrence and our patient was asymptomatic on the latest follow-up 5 months after discharge.

Conclusion

Despite accurate detection of acute mesenteric ischemia by contrast-enhanced computed tomography, high index of suspicion is indispensable for its early diagnosis. Early diagnosis and immediate anticoagulation will prevent subsequent complications and need for surgical intervention. Young patients without known risk factors presenting with venous thrombosis in atypical sites should be investigated for prothrombotic diseases.

Deep vein thrombosis and pulmonary embolism

Deep vein thrombosis and pulmonary embolism, collectively referred to as venous thromboembolism, constitute a major global burden of disease. The diagnostic work-up of suspected deep vein thrombosis or pulmonary embolism includes the sequential application of a clinical decision rule and D-dimer testing. Imaging and anticoagulation can be safely withheld in patients who are unlikely to have venous thromboembolism and have a normal D-dimer. All other patients should undergo ultrasonography in case of suspected deep vein thrombosis and CT in case of suspected pulmonary embolism. Direct oral anticoagulants are first-line treatment options for venous thromboembolism because they are associated with a lower risk of bleeding than vitamin K antagonists and are easier to use. Use of thrombolysis should be limited to pulmonary embolism associated with haemodynamic instability. Anticoagulant treatment should be continued for at least 3 months to prevent early recurrences. When venous thromboembolism is unprovoked or secondary to persistent risk factors, extended treatment beyond this period should be considered when the risk of recurrence outweighs the risk of major bleeding.

Utility of thrombophilia testing in patients with venous thrombo-embolism

BACKGROUND

Clinical practice of thrombophilia testing those with venous thrombo-embolism (VTE) in public hospitals may not be consistent with the international guidelines. This study aims to assess whether practice of thrombophilia testing in two public hospitals are consistent with international guidelines, and to assess whether certain groups of patients were more likely to benefit from testing.

METHODS

A retrospective audit on patients who presented to two Queensland public hospitals from August 2011 to September 2012 with VTE. Data were collected on demographics, yield of the test, and whether the result of the test changed the duration of anticoagulation. Group analysis was performed to identify patients who were more likely to yield positive results.

RESULTS

Of the 152 patients, 49% were tested for thrombophilia, of whom 31% returned a positive result. 38% of patients with provoked VTE were tested for thrombophilia, inconsistent with guideline recommendations. In 1.2% of cases there were documented changes to duration of anticoagulation with positive results. The rates of positive results were 45% in unprovoked VTE cases compared with 29% in provoked VTE cases (P=0.054). The rates of positive results were 52% in recurrent VTE cases compared with 27% in those cases with first episode of VTE (P=0.007).

CONCLUSIONS

The practice of thrombophilia testing in public hospitals was frequently inconsistent with guidelines, and did not significantly influence clinical decisions. There was higher yield of testing in patients with recurrent episodes of VTE and possibly in patients with unprovoked VTE.

Diagnosis and management of factor V Leiden

INTRODUCTION

The discovery of the factor V Leiden (FVL) missense mutation (Arg506Gln) causing factor V resistance to the anticoagulant action of activated protein C was a landmark that allowed a better understanding of the basis of inherited thrombotic risk. FVL mutation is currently the most common known hereditary defect predisposing to venous thrombosis. Areas covered: Novel data-driven FVL diagnosis and therapeutic approaches in the management of FVL carriers in various clinical settings. Brief conclusions on topics of direct clinical relevance including currently available indications for primary and secondary prophylaxis, the management of female, pediatric carriers and asymptomatic relatives. Latest evidence on the association between FVL and cancer, as well as the possible use of direct oral anticoagulant therapy. Expert commentary: Although FVL diagnosis nowadays is highly accurate, many doubts remain regarding the best management and therapeutic protocols. The main role of clinicians is to tailor therapeutic strategies to carriers and their relatives. High familial penetrance, distinctive aspects of the first thrombotic event (provoked/unprovoked, age, etc.) and laboratory biomarkers can guide the optimal management of secondary antithrombotic prophylaxis, primary prophylaxis in asymptomatic individuals, and whether to screen relatives.

Low-molecular-weight-heparin can benefit women with recurrent pregnancy loss and sole protein S deficiency: a historical control cohort study from Taiwan

BACKGROUND

Heritable thrombophilias are assumed important etiologies for recurrent pregnancy loss. Unlike in the Caucasian populations, protein S and protein C deficiencies, instead of Factor V Lieden and Prothrombin mutations, are relatively common in the Han Chinese population. In this study we aimed to investigate the therapeutic effect of low molecular weight heparin upon women with recurrent pregnancy loss and documented protein S deficiency.

METHODS

During 2011-2016, 68 women with recurrent pregnancy loss (RPL) and protein S deficiency (both the free antigen and function of protein S were reduced) were initially enrolled. All the women must have experienced at least three recurrent miscarriages. After excluding those carrying balanced translocation, medical condition such as diabetes mellitus, chronic hypertension, and autoimmune disorders (including systemic lupus erythematosus and anti-phospholipid syndrome), coexisting thrombophilias other than persistent protein S deficiency (including transient low protein S level, protein C deficiency, and antithrombin III), only 51 women with RPL and sole protein S deficiency were enrolled. Initially they were prescribed low dose Aspirin (ASA: 100 mg/day) and unfortunately there were still 39 women ended up again with early pregnancy loss (12 livebirths were achieved though). Low-molecular-weight-heparin (LMWH) was given for the 39 women in a dose of 1 mg/Kg every 12 h from the day when the next clinical pregnancy was confirmed to the timing at least 24 h before delivery. The perinatal outcomes were assessed.

RESULTS

Of 50 treatment subjects performed for the 39 women (i.e. 11 women enrolled twice for two pregnancies), 46 singletons and one twin achieved livebirths. The successful live-birth rate in the whole series was 94 % (47/50). Nineteen livebirths delivered vaginally whereas 28 delivered by cesarean section. The cesarean delivery rate is thus 59.57 %. Emergent deliveries occurred in 3 but no postpartum hemorrhage had been noted.

CONCLUSIONS

Our pilot study in Taiwan, an East Asian population, indicated anti-coagulation therapy is of benefit to women with recurrent pregnancy loss who had documented sole protein S deficiency.

TRIAL REGISTRATION

ISRCTN64574169. Retrospectively registered 29 Jun 2016.

Disappearing Inferior Vena Cava in A Pediatric Patient with Down Syndrome and Hereditary Thrombophilia

Absence of the infrarenal segment of the inferior vena cava is an extremely rare anomaly. The reasons for such a developmental failure are unclear. Most researchers believe that the cause lies in embryonic dysgenesis affecting separate segments or the entire inferior vena cava. Others suggest that absence of the inferior vena cava is not embryonic in origin, rather the result of intrauterine or perinatal thrombosis. We report a case here that during a period of six months, inferior vena cava first occluded, then become redundant in a baby girl with several chromosomal and gene defects, including Down syndrome and hereditary thrombophilia, admitted to our hospital due to the swelling and redness of the right lower extremity. From this observation, we propose that the absence of the inferior vena cave was not of embryonic origin but due to thrombosis.

A Successful Mother and Neonate Outcome for a Woman with Essential Thrombocytosis and FV Leiden Heterozygosity

Essential thrombocytosis (ET) and FV Leiden heterozygosity represent an acquired and hereditable hypercoagulable state, respectively. An uncommon case of coexistence of ET and FV Leiden heterozygosity in a 36-year-old pregnant woman and her successful pregnancy outcome is described. She was considered to be at high risk of thrombosis during her pregnancy and she was treated with both prophylactic dose of LMWH and aspirin daily throughout her pregnancy and for a 6-week period postpartum. The efficacy of the anticoagulation treatment was monitored in various time points not only by measuring anti-Xa levels and D-Dimers but also with new coagulation methods such as rotation thromboelastometry and multiplate. Global assessment of coagulation using additional newer laboratory tests might prove useful in monitoring coagulation pregnancies at high risk for thrombosis.

[Optimal duration of anticoagulant treatment after venous thromboembolic disease]

Determination of the optimal duration of anticoagulant treatment for venous thromboembolic disease (VTED) is a major step in the management of patients with this disease. The assessment depends on the identification of two sets of risk factors: those for recurrence after anticoagulant treatment is stopped and those for hemorrhage in cases of prolonged treatment. Nonetheless, the determination of the optimal duration remains controversial. Recent data finally make it possible to clarify this decision. Recent treatment trials demonstrate that patients at high risk of recurrence receive no sustained benefit from a prolonged but limited anticoagulant treatment. In other words, the choice is simplified: either the risk is low, and treatment for 3months is sufficient, or the risk is high, and treatment must be envisioned for an unlimited duration. Adequate identification of patients eligible for short or unlimited treatment is more crucial than ever and depends on the presence of determinant clinical variables, as the information from laboratory or morphologic tests is generally marginal. The risk of thromboembolic recurrence is low when the initial episode is triggered by a major reversible factor, and a short treatment of 3months is thus indicated. These inducing factors are mainly surgery, lower limb injuries, immobilization for a medical condition, pregnancy, or use of combined estrogen-progestin contraceptives. Among patients with VTED not induced by these factors, the risk of recurrence is high and requires planning anticoagulant treatment for an unlimited duration. Nonetheless, the risk of hemorrhage is a major constraint to such unlimited treatment. Accordingly, the perspectives for secondary prevention that is equally effective but has a lower risk of hemorrhage are currently under evaluation. Finally, patients with cancer are in a separate category, with a very high risk of recurrence that justifies treatment for at least 6months.

Impact of Inherited Prothrombotic Disorders on the Long-Term Clinical Outcome of Percutaneous Transluminal Angioplasty in Patients with Diabetes

The aim of our study was to analyse inherited thrombotic disorders that influence the long-term outcome of PTA. Methods. Diabetic patients with peripheral arterial disease (PAD) treated by PTA in our centre between 2008 and 2011 were included in the study. Patients were divided into unsuccessful PTA group (75 patients), successful PTA group (58 patients), and control group (65 patients, with diabetes but no PAD). Diagnosis of inherited thrombotic disorders included mutation in factor V (Leiden), factor II (prothrombin), and mutation in genes for methylenetetrahydrofolate reductase-MTHFR (C677T and A1298C). Results. The genotypic frequency of Leiden allele G1691A was significantly associated with a risk of unsuccessful PTA in comparison with successful PTA group and control group (OR 8.8 (1.1-70.6), p = 0.041, and OR 9.8 (1.2-79.2), p = 0.032, resp.). However, we only observed a trend for the association of the prothrombin allele G20210A and risk of PTA failure. The frequencies of alleles of MTHFR 677 or 1298 did not differ significantly among the groups. Conclusion. Our study showed higher frequency of heterozygous form of Leiden mutation in diabetic patients with unsuccessful outcome of PTA in comparison with patients with successful PTA and diabetic patients without PAD.