Clinical guidelines for testing for heritable thrombophilia

Met343Val mutation disrupts the shuttling of Trp380 leading to a low-activity conformer of activated protein C and causes thrombosis

BACKGROUND

Protein C (PC) pathway serves as a major defense mechanism against thrombosis by the activation of PC through the thrombin-thrombomodulin complex and subsequent inactivation of the activated factor (F)V (FVa) and FVIII (FVIIIa) with the assistance of protein S, thereby contributing to hemostatic balance. We identified 2 unrelated patients who suffered from recurrent thrombosis and carried the same heterozygous mutation c.1153A>G, p.Met343Val (M343V), in PROC gene. This mutation had not been previously reported.

OBJECTIVES

To explore the molecular basis underlying the anticoagulant defect in patients carrying the M343V mutation in PROC.

METHODS

We expressed PC-M343V variant in mammalian cells and characterized its properties through coagulation assays.

RESULTS

Our findings demonstrated that while activation of mutant zymogen by thrombin-thrombomodulin complex was slightly affected, cleavage of chromogenic substrate by APC-M343V was significantly impaired. However, Ca2+ increased the cleavage efficiency by approximately 50%. Additionally, there was a severe reduction in affinity between APC-M343V and Na+. Furthermore, the inhibitory ability of APC-M343V toward FVa was markedly impaired. Structural and simulation analyses suggested that Val343 might disrupt the potential hydrogen bonds with Trp380 and cause Trp380 to orient closer to His211, potentially interfering with substrate binding and destabilizing the catalytic triad of APC.

CONCLUSION

The M343V mutation in patients adversely affects the reactivity and/or folding of the active site as well as the binding of the physiological substrate to the protease, resulting in impaired protein C anticoagulant activity and ultimately leading to thrombosis.

Ser252Asn Mutation Introduces a New N-Linked Glycosylation Site and Causes Type IIb Protein C Deficiency

BACKGROUND

 Protein C (PC) is a vitamin K-dependent anticoagulant serine protease zymogen which upon activation by the thrombin-thrombomodulin (TM) complex downregulates the coagulation cascade by degrading cofactors Va and VIIIa by limited proteolysis. We identified a thrombosis patient who carried a heterozygous mutation c.881G > A, p.Ser252Asn (S252N) in PROC. This mutation was originally described in a report of novel mutations in patients presenting with defective PC anticoagulant activity in Paris. The research identified PC-S252N (the "Paris" mutation) in a propositus and her family members and highlighted the critical role of Ser252 in the anticoagulation process of activated PC (APC).

MATERIAL AND METHODS

 We expressed the PC-S252N mutant in mammalian cells and characterized the properties in coagulation assays to decipher the molecular basis of anticoagulant defect of this mutation.

RESULTS

 We demonstrated that PC-S252N had a diminished ability to TM binding, which resulted in its impaired activation by the thrombin-TM complex. However, APC-S252N exhibited a slightly stronger cleavage capacity for the chromogenic substrate. Meanwhile, the catalytic activity of APC-S252N toward FVa was significantly reduced. Sequence analysis revealed that Ser252 to Asn substitution introduced a new potential N-linked glycosylation site (252NTT254) in the catalytic domain of PC, which adversely affected both the activation process of PC and anticoagulant activity of APC.

CONCLUSION

 The new N-glycosylation site (252NTT254) resulting from the mutation of Ser252 to Asn252 in PROC affects the overall structure of the protease, thereby adversely affecting the anticoagulant function of protein C. This modification has a negative impact on both TM-promoted activation of protein C and APC cleavage of FVa, ultimately leading to thrombosis in the patient.

Protein C deficiency with venous and arterial thromboembolic events

Protein C (PC) is a key component of the vitamin K-dependent coagulation pathway. It exerts anticoagulant effects by inactivating factors V and VIII. Acquired or inherited PC deficiency results in a prothrombotic state, with presentations varying from asymptomatic to venous thromboembolism. However, there has been an increasing number of reports linking PC deficiency to arterial thromboembolic events, such as myocardial infarction and ischemic stroke. This editorial focuses on the association between PC deficiency and thromboembolism, which may provide some insights for treatment strategy and scientific research.

Two cases of venous thromboembolism in siblings after splenectomy due to a novel PROC gene mutation

BACKGROUND

Venous thromboembolism(VTE)is a common multifactorial disease. Anticoagulant protein deficiency is the most usual hereditary thrombophilia in the Chinese people, which includes protein C(PC), protein S and antithrombin deficiencies.

CASE PRESENTATION

A retrospective analysis was conducted on clinical manifestations, laboratory tests, genetic information, and other relevant data of siblings diagnosed with VTE in 2020 at the Department of Pediatrics of Shenzhen Second People's Hospital. The proband, a 12-year-old female, was admitted to the hospital in December 2020 with a complaint of pain in the left lower limb for four days. The examination found that the PC activity was 53%, and B-ultrasound showed bilateral thrombosis of the great saphenous vein in the thigh segment. The proband's younger brother, a 10-year-old male, was admitted to the hospital in January 2021 due to right lower limb pain for two weeks. PC activity is 40%. B-ultrasound showed superficial venous thrombosis in the left lower limb and upper limb. Both siblings suffered from thalassemia and underwent splenectomy before recurrent thrombosis occurred. The proband's mother was asymptomatic, and her PC activity was 45%. Both cases were treated with warfarin anticoagulation, and their symptoms improved. The proband's mother was found to have a heterozygous mutation at this locus through Sanger sequencing.

CONCLUSION

Protein C deficiency should be considered for venous thromboembolism in childhood. The heterozygous mutation 1204 A > G in PROC exon 9 in this family is reported for the first time.

Exploring the potential for a set of UK hormone replacement therapy eligibility guidelines: A suggested proposal on the topic of venous thromboembolism

OBJECTIVE

To explore the feasibility for a set of hormone replacement therapy (HRT) eligibility guidelines that follow a similar structure and appearance to the UKMEC guidance for contraception. To enable non-specialists to feel confident in safely prescribing HRT and to aid selection of the most appropriate first line treatment.

METHODS

A literature review was undertaken with evidence summarised on the topic of venous thromboembolism (VTE) which is an area frequently considered a barrier to prescribing. Medical eligibility tables which separated HRT by type were then produced for a set of VTE-related topics.

RESULTS

The literature search confirmed the importance of distinguishing between different types and routes of administration when considering the suitability of HRT. Much of the evidence has been based on older synthetic types of HRT and whilst they still have a role in management, these medications carry different risks to the now more accepted use of body identical types. The search also highlighted the nuances involved, increasing the complexity of forming guidelines, with the need for consideration to be given to an individual's own perception of risks and benefits.

CONCLUSION

The demand for HRT has risen in recent years and there is a need for this to be managed effectively, particularly for patients in primary care. The production of this type of guidance will enable the non-specialist to feel confident in safe and evidence-based prescribing. The guidelines are also designed to demonstrate to prescribers which complex patients should be referred onto menopause specialists.

Do we need more guidance on thrombophilia testing? Challenges and special considerations

INTRODUCTION

Thrombophilia testing (TT) is a laboratory procedure designed to detect the risk factors involved in the pathogenesis of vascular occlusions. The role of TT is also controversial because it has a limited impact on the choice and duration of antithrombotic treatments.

AREAS COVERED

We reviewed, by examining MEDLINE up to October 2023. Accepted and not accepted thrombophilia markers are discussed along with the appropriateness or not of prescribing TT in several conditions such as: provoked and unprovoked venous thromboembolism (VTE), women who are planning a pregnancy whose relatives had VTE or have a hereditary thrombophilia, before assumption of estro-progestins, after multiple pregnant loss, arterial thrombosis, retinal vein occlusion, and splanchnic vein thrombosis.

EXPERT OPINION

TT is not essential in the management of VTE, but it may be useful for limiting adverse events in case of thrombophilia. We expose our criticism of items afforded by other guidelines by presenting our opinion based on both the scientific evidence and clinical practice. We also deal with common mistakes in prescribing and interpretations of TT hoping to purpose an educational approach on this topic. Finally, we emphasize the creation of the expert in hemostasis and thrombosis who should be present in every hospital.

Multi-valve Libman-Sacks's endocarditis-related multiple, massive and fatal systemic embolization. A case report and a review of diagnostic work-up

We reported a case of non-bacterial thrombotic endocarditis (NBTE) in a 37-year-old woman who presented with signs and symptoms of cardio-embolic cerebral stroke caused by a prothrombotic state due to underlying advanced uterine cancer. Multimodal imaging, including 3D-ecocardiography, as well as laboratory and cultural tests, were critical in making the diagnosis. After starting anticoagulation therapy with low molecular weight heparin (LMWH), the patient underwent surgical aortic valve replacement due to worsening aortic valve function, initial left ventricle enlargement, increasing dimensions, and mobility of vegetations. Unfortunately, vegetations relapsed on the aortic valve bio-prosthesis as well as the mitral leaflets, resulting in a final picture of multi-valve NBTE. The fatal outcome was due to a massive multiple limb embolism, which resulted in leg amputations and septical complications. Starting with the case, we present a brief overview of the pathology's presentation, treatment, management, and prognosis, as well as the diagnostic work-up.

Low value of inherited thrombophilia testing among patients with stroke or transient ischemic attack: A three-year retrospective study

BACKGROUND/PURPOSE

Inherited thrombophilia testing in the acute inpatient setting is controversial and expensive, and rarely changes clinical management. We evaluated ordering patterns and results of inpatient inherited thrombophilia testing for patients who presented with an isolated acute ischemic stroke or transient ischemic attack (TIA) without concurrent venous thromboembolism.

METHODS

We retrospectively analyzed patients admitted for acute ischemic stroke or TIA between January 1st, 2019 and December 31st, 2021 at Thomas Jefferson University Hospitals in Philadelphia, PA and who underwent inherited thrombophilia testing during the hospital admission. Charts were reviewed to determine stroke risk factors, test results, and clinical management.

RESULTS

Among 2108 patients admitted for acute ischemic stroke or TIA (including branch and central retinal artery occlusions) during the study period, the study included 249 patients (median age 49.0 years, 50.2% female) who underwent inpatient testing for factor V Leiden, prothrombin G20210A variant, hyperhomocysteinemia, PAI-1 elevation, and deficiencies of protein C and S and antithrombin. 42.2% of patients had at least one abnormal test, and among the 1035 tests ordered, 14.3% resulted abnormal. However, 28% of abnormal tests were borderline positive antigen or activity assays that likely represented false positives. There was no significant difference in the likelihood of a positive test among patients without stroke risk factors vs those with risk factors (47.1% vs 40.9%, P = .428), nor any significant difference between those under vs over age 50 years (45.7% vs 38.3%, P = .237). No patients with an abnormal result had their clinical management changed as a result. Charges for the tests totaled $468,588 USD.

CONCLUSIONS

Inherited thrombophilia testing in the hospital immediately following isolated acute arterial ischemic stroke or TIA was associated with high rates of likely false positive results and was expensive. Positive results did not change clinical management in a single case.

Laboratory Evaluation of Antithrombin, Protein C, and Protein S

Thrombophilia is a complex disease process, clinically manifesting in various forms of venous thromboembolism. Although both genetic and acquired (or environmental) risks factors have been reported, the presence of a genetic defect (antithrombin [AT], protein C [PC], protein S [PS]) is considered three of the major contributing factors of thrombophilia. The presence of each of these risk factors can be established by clinical laboratory analysis; however, the clinical provider and laboratory personnel must understand the testing limitations and shortcomings associated with the assays for these factors to be able to ensure an accurate diagnosis. This article will describe the major pre-analytical, analytical, and post-analytical issues associated with the various types of assays and discuss evidence-based algorithms for analyzing AT, PC, and PS in plasma.

Acute Portal Vein Thrombosis as an Initial Presentation of Protein C Deficiency: A Case Report

Protein C (PC) is an essential vitamin K-dependent protein that regulates thrombosis and hemostasis in the body. A mutation in the PROC gene on chromosome 2q14.3 results in PC deficiency. The clinical presentation of PC deficiency can vary, ranging from a single vein thrombosis to disseminated intravascular coagulation, purpura fulminans, or even life-threatening complications such as sepsis. Here, we present a case of a 37-year-old female who was found to have acute portal vein thrombosis as an initial presentation of PC deficiency. She presented to the hospital with acute onset of abdominal pain associated with nausea, blood-streaked emesis, and bloody bowel movement.

Adherence to thrombophilia testing guidelines and its influence on anticoagulation therapy: A single-center cross-sectional study

INTRODUCTION

The collected evidence on thrombophilia guidelines is scarce and data about their impact on clinical decisions are unknown. We aimed to investigate the adherence to thrombophilia testing guidelines, its therapeutic impact in patients with guideline-adherent and non-adherent testing and identify the patients' clinical characteristics mostly associated with treatment decisions.

MATERIALS AND METHODS

We conducted a single-center cross-sectional study of patients referred for thrombophilia testing at the outpatient clinic of a tertiary hospital between 01/2010-10/2020. We systematically evaluated the adherence of thrombophilia testing to internal guidelines and the influence of test results on anticoagulation therapy. Using multivariable logistic regression, we evaluated the association between clinical characteristics and influence of thrombophilia tests on anticoagulation therapy in the entire cohort and by indication for referral.

RESULTS

Of 3686 included patients, mostly referred for venous thromboembolism (2407, 65 %) or arterial thrombosis (591, 16 %), 3550 patients (96 %) underwent thrombophilia testing. Indication for testing was according to guidelines in 1208 patients (33 %). Test results influenced treatment decisions in 56 of 1102 work-ups (5.1 %) that were adherent to guidelines, and in 237 of 2448 (9.7 %) non-adherent work-ups (absolute difference, 4.3 %; 95 % confidence interval, 2.9-6.3 %). Age < 50 years, female sex, absence of risk factors and co-morbidities, weakly provoked venous thromboembolism and referral indication other than venous thromboembolism were associated with influence on anticoagulation therapy.

CONCLUSIONS

Adherence to guidelines for thrombophilia testing was poor and did not have an impact on treatment decisions. Refinement of selection criteria is needed to increase the therapeutic impact of thrombophilia testing.

Hormone replacement therapy in women with history of thrombosis or a thrombophilia

Findings from the Women's Health Initiative (WHI) randomised placebo-controlled trial (RCT) were published at the beginning of this century. They suggested that hormone replacement therapy (HRT) use increased the risk of cardiovascular disease and venous thromboembolism including pulmonary embolism and deep vein thrombosis The findings led to a decline in HRT prescriptions and negative publicity about the use of HRT for women with significant menopausal symptoms. Subsequent studies have shown that the risk of thrombosis with HRT relates to whether estrogen is combined with a progestogen and the route of administration of estrogen. In healthy women with no background medical problems, transdermal hormone replacement is not associated with an increased risk of thrombosis. However, much less is known about the safety of various HRT preparations in women with a high background risk of thrombosis. These cases can often be challenging for clinicians with uncertainties around testing for thrombophilia, use of anticoagulation and striking a balance between the risks and benefits of prescribing HRT. This article will review the mechanism of thrombosis with differing types of HRT and present the evidence from the relevant trials. The article will also present the evidence that specifically relates to women with a personal history of thrombosis or thrombophilia (heritable and acquired) to enable clinicians to better individualise the risk assessment for each woman requesting HRT and understand the role of thrombophilia screening or concomitant anticoagulation in such situations.

A Review of Systemic Hematological Manifestations and Stent Thrombosis

Stent thrombosis (ST) has significant morbidity and mortality following percutaneous coronary intervention (PCI). ST is uncommon making the identification of nonprocedural predictors challenging. Numerous case reports of ST in both benign and malignant hematological conditions exist. Given ST could be a Herald event of an undiagnosed condition and condition-specific treatment may be available, it is important to consider specialist testing in an unexplained ST. This review included a case presentation of ST in previously undiagnosed paroxysmal nocturnal hemoglobinuria (PNH) and a literature review of ST in other acquired thrombophilias including myeloproliferative disorders (MPNs), antiphospholipid syndrome, hematological malignancies, and heparin-induced thrombocytopenia (HIT). Inherited thrombophilias and common pitfalls in thrombophilia and coagulation testing are also discussed. The cardiac-hematology landscape is becoming increasingly complex and there is a paucity of how to best manage ST in these patients. There is clear variability in practice and the use of multidisciplinary input between cardiologists and hematologists is essential.

Antithrombin diagnostics by mass spectrometry: Development and analytical validation of a next-generation test

Background

Antithrombin deficiency is a rare but severe disorder leading to high risk of thrombosis. The current clinical care pathway relies on activity tests, which only provide overall functional information on the in vitro activity of antithrombin. However, antithrombin exists in many different forms, also known as proteoforms, with varying clinical phenotypes. Precision diagnostics, facilitated by mass spectrometry, provides a strategy to improve patient diagnostics by molecular characterization.

Objectives

To develop and analytically validate a mass spectrometry-based test for molecular characterization of antithrombin.

Methods

The test was analytically validated based on predefined analytical performance specifications. The validation covered imprecision, carryover, linearity, stability, analytical specificity, a provisional reference interval, and an explorative method comparison.

Results

The test passed the predefined analytical performance specifications with a mean within-laboratory imprecision of 5.9%, linearity between 0.08 and 2.58 μmol/L, and a provisional reference interval of 1.07 to 1.49 μmol/L. When measuring samples with a suspected quantitative deficiency, the test showed a good correlation with a commercial activity test (Pearson r = 0.88).

Conclusion

The test passed the validation, and we now envision the use of the test for exploration of the clinical relevance of specific antithrombin proteoforms. Puzzling cases of antithrombin deficiency, for instance, due to ambiguous activity results or an atypical clinical presentation, can be investigated by the LC-MRM mass spectrometry test serving as an add-on to the activity test and providing a molecular diagnosis. Clinical studies are planned to investigate the potential of the test to improve antithrombin diagnostics. Furthermore, the molecular information gained using the test may aid in establishing better risk stratification and a basis for personalized medicine.

Venous Thromboembolic Events are Exceedingly Rare in Spinal Fusion for Adolescent Idiopathic Scoliosis

STUDY DESIGN

Review of health care record database and determination of population statistics.

OBJECTIVE

The purpose of this study was to quantify the incidence of clinically significant venous thromboembolic (VTE) events in patients undergoing spinal fusion surgery for adolescent idiopathic scoliosis (AIS) and to identify risk factors for VTE.

SUMMARY OF BACKGROUND DATA

VTE is a serious complication that can cause disability and even death following surgery. Incidence of VTE following AIS surgery has not been well studied; the use of a national database allows the assessment of rare, yet important complications.

MATERIALS AND METHODS

The PearlDiver Database was used to identify AIS patients who underwent primary instrumented spinal fusion between 2010 and 2020. Patient records were cross-referenced for documented VTEs within 30 and 90 postoperative days. Patients with nonidiopathic scoliosis were excluded. Logistic regression was used to evaluate risk factors for correlation with VTE events.

RESULTS

Thirty-eight of 11,775 (0.323%) patients undergoing surgery for AIS developed a VTE complication within 90 postoperative days. Hypercoagulability [odds ratio (OR)=13.50, P <0.0001], spinal fusion involving 13+ vertebral levels (OR=2.61, P <0.0001), obesity (OR=1.30, P <0.005), and older (15-18 y) compared with younger adolescence (10-14 y) (OR=2.12, P <0.0001) were associated with VTE. Seven of 38 (18.4%) patients with a diagnosed thrombophilia experienced VTE.

CONCLUSIONS

The incidence of clinically significant VTEs in pediatric patients following spinal fusion surgery for AIS is low with an incidence of 0.323%. Postoperative chemoprophylaxis in the general pediatric population is not indicated. Patients with obesity, those undergoing spinal fusion of 13 or more vertebrae, and adolescents 15-18 years old were found to have higher but still small risk of VTE following surgery. Further prospective studies are needed to validate the risk profile of patients with hypercoagulability and establish clinical guidelines for use of postoperative chemoprophylaxis in this cohort.

LEVEL OF EVIDENCE

Level III.

Laboratory Evaluation of Thrombophilia

Venous thromboembolism (VTE) occurs typically in the veins of the lower extremities and/or as pulmonary embolism. There is a myriad of causes of VTE ranging from provoked causes (e.g., surgery, cancer) to unprovoked causes (e.g., inherited abnormalities) or multiple factors that combine to initiate the cause. Thrombophilia is a complex, multi-factorial disease that may result in VTE. The mechanism(s) and causes of thrombophilia are complex and not completely understood. In healthcare today, only some answers about the pathophysiology, diagnosis, and prevention of thrombophilia have been elucidated. The laboratory analysis for thrombophilia is not consistently applied, and has changed over time, but remains varied by providers and laboratories as well. Both groups must establish harmonized guidelines for patient selection and appropriate conditions for analysis of inherited and acquired risk factors. This chapter discusses the pathophysiology of thrombophilia, and evidence-based medicine guidelines discuss the optimum laboratory testing algorithms and protocols for selection and analyzing VTE patients to ensure a cost-effective use of limited resources.

Reducing inappropriate inpatient thrombophilia testing through an electronic health record intervention

Current literature does not support routine testing for hereditary and acquired thrombophilia disorders in the inpatient setting. Testing in the acute setting rarely changes patient management or could lead to patient mismanagement. Despite prior educational interventions, continued overuse of inpatient testing warrants further quality improvement measures. A hard-stop best practice advisory pop-up was implemented in the electronic medical record in a multicenter academic hospital system to provide clinicians guidance on the appropriate use of thrombophilia testing at the point of care. Pre- and postintervention retrospective data were collected to assess clinical features before and after implementation. Before the intervention, 271 patients underwent inpatient hypercoagulability testing; after the intervention, 238 patients underwent inpatient hypercoagulability testing. The total number of labs ordered per patient decreased from 1185 to 910, a 13% reduction (P = 0.003). Overall, there was a savings of $23,597 in total direct cost and $123,153 in total charges when comparing the 6-month timeframes before and after the intervention (P < 0.01). Although this study found only mild reductions in thrombophilia testing, it presents a new means of providing point-of-care intervention and education for hypercoagulability testing in the inpatient setting.

Hemostatic and Thrombotic Considerations in the Diagnosis and Management of Childhood Arterial Ischemic Stroke: A Narrative Review

Although rare in children, arterial ischemic stroke (AIS) is associated with increased mortality and neurological morbidity. The incidence of AIS after the neonatal period is approximately 1-2/100,000/year, with an estimated mortality of 3-7%. A significant proportion of children surviving AIS experience life-long neurological deficits including hemiparesis, epilepsy, and cognitive delays. The low incidence of childhood AIS coupled with atypical clinical-presentation and lack of awareness contribute to delay in diagnosis and consequently, the early initiation of treatment. While randomized-clinical trials have demonstrated the efficacy and safety of reperfusion therapies including thrombolysis and endovascular thrombectomy in appropriately-selected adult patients, similar data for children are unavailable. Consequently, clinical decisions surrounding reperfusion therapy in childhood AIS are either extrapolated from adult data or based on local experience. The etiology of childhood AIS is multifactorial, often occurring in the setting of both acquired and congenital risk-factors including thrombophilia. While multiple studies have investigated the association of thrombophilia with incident childhood AIS, its impact on stroke recurrence and therefore duration and intensity of antithrombotic therapy is less clear. Despite these limitations, a significant progress has been made over the last decade in the management of childhood AIS. This progress can be attributed to international consortiums, and in selected cohorts to federally-funded clinical trials. In this narrative review, the authors have systematically appraised the literature and summarize the hemostatic and thrombotic considerations in the diagnosis and management of childhood AIS focusing on the evidence supporting reperfusion therapies, relevance of thrombophilia testing, and duration and drug choices for secondary-prophylaxis.

Microsurgical Breast Reconstruction in Patients with Disorders of Hemostasis: Perioperative Risks and Management

BACKGROUND

Surgical and technological advances have resulted in the widespread adoption of microsurgical breast reconstruction. Many comorbidities that potentially might impair vasculature and wound healing are no longer considered contraindications for these procedures. However, some uncertainty still prevails regarding the perioperative management of patients with disorders of hemostasis.

METHODS

The authors combined a literature review with a retrospective chart review of patients with disorders of hemostasis who had undergone microsurgical breast reconstruction at the senior author's (J.F.) center between 2015 to 2020. Several disorders associated with thrombotic and/or hemorrhagic complications were identified, and a standardized risk assessment and management strategy was developed in cooperation with a hematologist.

RESULTS

Overall, 10 studies were identified comprising 29 patients who had a defined disorder of hemostasis and underwent microsurgical breast reconstruction. Seventeen microsurgical breast reconstructions were performed on 11 patients at the senior author's (J.F.) center. High factor VIII levels, heterozygous factor V Leiden, and heterozygous prothrombin mutation G20210A were the most common genetic or mixed genetic/acquired thrombophilic conditions. As expected, hereditary antithrombin, protein C, or protein S deficiencies were rare. Among hemorrhagic disorders, thrombocytopenia, platelet dysfunction, and von Willebrand disease or low von Willebrand factor levels were those factors most frequently associated with increased perioperative bleeding.

CONCLUSIONS

Patients should be screened for elevated risk of thrombosis or bleeding before undergoing microsurgical breast reconstruction, and positive screening should prompt a complete hematologic evaluation. Interdisciplinary management of these disorders with a hematologist is essential to minimize risks and to obtain optimal reconstructive results.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, IV.

Laboratory Testing for the Evaluation of Phenotypic Activated Protein C Resistance

Activated protein C (APC) resistance (APCR) is considered a risk factor of venous thromboembolism (VTE). The most common genetic disorder conferring APCR is a factor (F) V Leiden mutation, but many other factors are also implicated, such as other F5 mutations (e.g., FV Hong-Kong and FV Cambridge), protein S deficiency, elevated factor VIII, exogenous hormone use, pregnancy and postpartum, depending on how APCR is defined. Considering the large population affected, the detection of this phenotype is crucial. Two types of tests are currently available: clotting time-based assays (with several versions) and thrombin generation-based assays with the endogenous thrombin potential (ETP)-based assay. The purpose of this review is therefore to discuss the performances of these tests and the cases in which it would be appropriate to use one over the other. Initially, as APCR was thought to be solely related to the FV Leiden mutation, the objective was to obtain a 100% specific assay. Clotting-time based assays were thus specifically designed to detect this inherited condition. Later on, an APCR condition without a FV Leiden mutation was identified and highlighted as an independent risk factor of VTE. Therefore, the development of a less specific assay was needed and a global coagulation test was proposed, known as the ETP-based APCR assay. In light of the above, these tests should not be used for the same purpose. Clotting time-based assays should only be recommended as a screening test for the detection of FV mutations prior to confirmation by genetic testing. On the other hand, the ETP-based APC resistance assay, in addition to being able to detect any type of APCR, could be proposed as a global screening test as it assesses the entire coagulation process.

Laboratory Testing for the Evaluation of Phenotypic Activated Protein C Resistance

Activated protein C (APC) resistance (APCR) is considered a risk factor of venous thromboembolism (VTE). The most common genetic disorder conferring APCR is a factor (F) V Leiden mutation, but many other factors are also implicated, such as other F5 mutations (e.g., FV Hong-Kong and FV Cambridge), protein S deficiency, elevated factor VIII, exogenous hormone use, pregnancy and postpartum, depending on how APCR is defined. Considering the large population affected, the detection of this phenotype is crucial. Two types of tests are currently available: clotting time-based assays (with several versions) and thrombin generation-based assays with the endogenous thrombin potential (ETP)-based assay. The purpose of this review is therefore to discuss the performances of these tests and the cases in which it would be appropriate to use one over the other. Initially, as APCR was thought to be solely related to the FV Leiden mutation, the objective was to obtain a 100% specific assay. Clotting-time based assays were thus specifically designed to detect this inherited condition. Later on, an APCR condition without a FV Leiden mutation was identified and highlighted as an independent risk factor of VTE. Therefore, the development of a less specific assay was needed and a global coagulation test was proposed, known as the ETP-based APCR assay. In light of the above, these tests should not be used for the same purpose. Clotting time-based assays should only be recommended as a screening test for the detection of FV mutations prior to confirmation by genetic testing. On the other hand, the ETP-based APC resistance assay, in addition to being able to detect any type of APCR, could be proposed as a global screening test as it assesses the entire coagulation process.

Laboratory Testing for the Evaluation of Phenotypic Activated Protein C Resistance

Activated protein C (APC) resistance (APCR) is considered a risk factor of venous thromboembolism (VTE). The most common genetic disorder conferring APCR is a factor (F) V Leiden mutation, but many other factors are also implicated, such as other F5 mutations (e.g., FV Hong-Kong and FV Cambridge), protein S deficiency, elevated factor VIII, exogenous hormone use, pregnancy and postpartum, depending on how APCR is defined. Considering the large population affected, the detection of this phenotype is crucial. Two types of tests are currently available: clotting time-based assays (with several versions) and thrombin generation-based assays with the endogenous thrombin potential (ETP)-based assay. The purpose of this review is therefore to discuss the performances of these tests and the cases in which it would be appropriate to use one over the other. Initially, as APCR was thought to be solely related to the FV Leiden mutation, the objective was to obtain a 100% specific assay. Clotting-time based assays were thus specifically designed to detect this inherited condition. Later on, an APCR condition without a FV Leiden mutation was identified and highlighted as an independent risk factor of VTE. Therefore, the development of a less specific assay was needed and a global coagulation test was proposed, known as the ETP-based APCR assay. In light of the above, these tests should not be used for the same purpose. Clotting time-based assays should only be recommended as a screening test for the detection of FV mutations prior to confirmation by genetic testing. On the other hand, the ETP-based APC resistance assay, in addition to being able to detect any type of APCR, could be proposed as a global screening test as it assesses the entire coagulation process.

Gerinnungsdiagnostik im klinischen Alltag – Teil 2

Während bei einer Vitamin-K-Antagonisten-Therapie die Therapieüberwachung (International Normalized Ratio [INR]) obligat ist, gilt dies für direkte orale Antikoagulanzien (DOAK) oder niedermolekulares Heparin (NMH) nur in ausgewählten klinischen Szenarien. Bei DOAK steht die Bestimmung von Tal- und Spitzenspiegeln des Medikaments im Plasma im Vordergrund, bei NMH die Anti-Xa-Aktivität. Der Zeitpunkt der Probenabnahme in Relation zur Einnahme ist für die Bewertung essenziell. Eine neu aufgetretene Thrombozytopenie im Rahmen stationärer Behandlungen ist häufig. Einordnung der Grunderkrankung, Tag des Auftretens sowie Erfassung medikamentöser Einflüsse und ihrer Dynamik ermöglichen oft die Eingrenzung der Ursache. Die Thrombophilietestung nach venöser Thromboembolie wird aufgrund fehlender therapeutischer Konsequenz zunehmend seltener durchgeführt. Ein Antiphospholipidsyndrom darf aber nicht übersehen werden, da sowohl die Therapiedauer als auch die Wahl des Antikoagulans davon abhängen.

Management of Central Venous Catheters in Children and Adults on Home Parenteral Nutrition: A French Survey of Current Practice

Although central venous catheter (CVC)-related thrombosis (CRT) is a severe complication of home parenteral nutrition (HPN), the amount and quality of data in the diagnosis and management of CRT remain low. We aimed to describe current practices regarding CVC management in French adult and pediatric HPN centers, with a focus on CVC obstruction and CRT. Current practices regarding CVC management in patients on HPN were collected by an online-based cross-sectional survey sent to expert physicians of French HPN centers. We compared these practices to published guidelines and searched for differences between pediatric and adult HPN centers’ practices. Finally, we examined the heterogeneity of practices in both pediatric and adult HPN centers. The survey was completed by 34 centers, including 21 pediatric and 13 adult centers. We found a considerable heterogeneity, especially in the responses of pediatric centers. On some points, the centers’ responses differed from the current guidelines. We also found significant differences between practices in adult and pediatric centers. We conclude that the management of CVC and CRT in patients on HPN is a serious and complex situation for which there is significant heterogeneity between HPN centers. These findings highlight the need for more well-designed clinical trials in this field.

A call to action: MTHFR polymorphisms should not be a part of inherited thrombophilia testing

Testing for polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene is still a standard part of thrombophilia testing in many laboratories. However, it is clear that these polymorphisms are not risk factors for arterial or venous thrombosis and therefore should not be part of thrombophilia testing. Eliminating MTHFR from thrombophilia testing will reduce patient concerns and health care costs.

Inherited thrombophilia transpires with severe coronary arterial thrombosis in wide range of age backgrounds: A report of 3 cases

Introduction

and importance: Protein C and S deficiency are some of the coagulation cascade disorders which may also contributes not only to venous thromboembolism (VTE), but also rarely to arterial thrombosis. Here we present a report of 3 severe coronary artery disease (CAD) cases ranging from very young to elderly patients with concomitant inherited thrombophilia.

Case presentation

The first case was a chronic coronary syndrome from a very young male patient with history of VTE without any other risk factor of CAD. The second case was about premature CAD with triple chronic total occlusion (RCA, LCX, LAD) in patient under 45 years old, with single risk factor. The third case was about accelerated atherosclerosis progression from previously non significant stenosis in RCA into total occlusion in RCA and inferior STEMI in old patient on supposely adequate double anti platelet agent.

Clinical discussion

All patients had protein C and/or S deficiency and first degree family history of VTE, therefore inherited thrombophilia was diagnosed. We gave them oral anticoagulant in addition to their standard treatment for secondary prevention with good outcome and without further adverse event.

Conclusion

It is important to raise awareness to perform screening inherited thrombophilia as an important risk factor for CAD in special subgroup such as young age patient with rapid course progression and family history of VTE. The use of oral anticoagulants as either prophylactic or therapeutic purpose in patients with inherited thrombophilia are safe and effective. However, further research is still needed.

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Inherited thrombophilia is a rare disease that can causes coronary arterial thrombosis.

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Inherited thrombophilia screening should be done in special subgroup of patients.

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There is no treatment guideline for CAD patients with inherited thrombophilia.

Hereditary Thrombophilia Testing Among Hospitalized Patients: Is It Warranted?

Background

Hereditary thrombophilias (HTs) are a group of inherited disorders that predispose the carrier to venous thromboembolism (VTE). It is estimated that 7% of the population has some form of HT. Although testing for HT has become routine for many hospitalized patients, knowing when to order the tests and how to interpret the results remains challenging. In the United States, there are no clear guidelines regarding testing for HT. We conducted a study to evaluate the utilization of HT testing among hospitalized patients to examine its impact on immediate management decisions and overall cost burden. In addition, we discuss the common reasons for healthcare providers to order these tests and review the data behind these reasons in the literature.

Methodology

A retrospective analysis of 2,402 patients who underwent HT testing between February 1, 2016, and January 31, 2018, was conducted. Eligible patients had at least one HT test ordered during hospitalization. The primary outcome was to determine the incidence of positive actionable tests. A positive actionable test was defined as a positive result that changed the anticoagulation intensity, type, or duration. Patients with a history of previous VTE, ongoing medical conditions requiring life-long anticoagulation, or unprovoked VTE were considered non-actionable.

Results

Among the 2,402 patients, 954 patients met the inclusion criteria with a mean age of 54 years. A total of 397 (41.6%) tests were ordered for acute VTE, while the rest were for non-VTE conditions, such as stroke, pregnancy complications, peripheral artery diseases, and others. Only 89 positive tests were actionable (14% of the positive tests, and 9.3% of the total ordered tests). There was a statistically significant association between increasing age and having both a positive test result (p = 0.006) and an actionable test (p = 0.046). The total cost of ordering these tests was estimated to be $566,585.

Conclusions

HT testing in the inpatient setting did not alter management in many cases and was associated with increased healthcare costs. The decision to order these tests should be individualized based on the clinical scenario.

[Cerebral venous sinus thrombosis : An overview of causes, diagnostics and treatment]

Die Sinus‑/Hirnvenenthrombose ist eine teils fulminant verlaufende, jedoch mit einer Inzidenz von 1,32 Fällen pro 100.000 Personenjahre eher seltene neurologische Diagnose. Nichtsdestotrotz ist die Erkrankung für etwa 0,5–1 % aller Schlaganfälle verantwortlich. Die neurologische Untersuchung zeigt oft ein unspezifisches Bild, gerade bei jüngeren Patientinnen mit akut bis subakut aufgetretenen, lageabhängigen Kopfschmerzen sollte diese Differenzialdiagnose jedoch unbedingt bedacht werden. Im Rahmen dieses Artikels erfolgt die Präsentation der häufigsten Ursachen, einschließlich eines Exkurses zur vakzininduzierten immunthrombotischen Thrombozytopenie (VITT), und es werden Empfehlungen zur klinischen, laborchemischen und bildgebenden Diagnostik gegeben. Zudem werden relevante Komplikationen, mit besonderem Augenmerk auf epileptische Anfälle im Rahmen der Krankheitsentität und die leitliniengemäße Akuttherapie und Sekundärprophylaxe dargestellt.

Lateral sinus thrombosis in a young patient with sudden neurosensorial hearing loss and genetic thrombophilia: A case report

Sensorineural hearing loss (SSHL) with a sudden onset is frequently encountered as a medical emergency in the ear, nose and throat (ENT) practice. The exact pathophysiology of the disease remains unknown, with the most likely etiologies being viral infection, inflammation, drug toxicity, trauma, or autoimmune response. Even though thrombophilia and cerebrovascular complications may lead, among others, to sudden neurosensorial hearing loss, its diagnosis is most often made following the onset of thrombotic complications. A case of a young female patient with unknown congenital hypercoagulation status complicated with lateral sinus thrombosis and unilateral drug-induced reversible hearing loss is presented. Molecular testing confirmed the diagnosis of genetic thrombophilia, due to the homozygous V Leiden, homozygous MTHFR A1298C, and heterozygous MTHFR C677T mutations. Although hereditary thrombophilia is a well-known topic in medical practice, current guidelines require continuous improvement, especially among patients treated in departments where this pathology is more difficult to recognize and manage.

Current Knowledge on Factor V Leiden Mutation as a Risk Factor for Recurrent Venous Thromboembolism: A Systematic Review and Meta-Analysis

Background

Thrombophilia screening is widely done in clinical practice, and it is claimed that the extent of venous thromboembolism (VTE) recurrence risk in patients with common defects is still not fully understood.

Aim

We aimed to summarize data of all observational studies prospectively assessing the association of heterozygous factor V Leiden (FVL) mutation and recurrent VTE in patients with VTE, and to calculate pooled relative risks (RR), overall and in various subgroups.

Methods

We searched MEDLINE and EMBASE databases for cohort studies prospectively assessing VTE recurrence in patients with and without FVL mutation (PROSPERO: CRD42021182800). Data were extracted on cohort and study-level. The methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). RR were calculated overall and in subgroups using a random-effects model.

Results

From 31 cohorts, 24 studies were finally included summarizing 13,571 patients. Heterozygous FVL mutation was identified in 2,840 individuals (21%). The methodological quality was estimated to be high in 20 studies (83%). The overall RR was 1.46 (95% CI: 1.31, 1.64), consistent across subgroups.

Conclusions

Pooling all high-quality epidemiological data, the risk of recurrent VTE was increased by 46% in patients with heterozygous FVL mutation. Against the background of established risk factors, the FVL mutation plays only a marginal role in the risk assessment for recurrent VTE.

Venous Thromboembolism Among Patients With Inflammatory Bowel Diseases is Not Related to Increased Thrombophilia: A Case-Control Study

GOAL

The aim was to assess whether thrombophilia significantly contributes to the risk of venous thromboembolic events (VTEs) in patients with inflammatory bowel disease (IBD).

BACKGROUND

Patients with IBD have a high risk of VTE. The underlying mechanism has been only partially defined.

METHODS

A case-control study in adults with IBD and an episode of VTE (IBD-VTE) were matched and compared with non-IBD patients with a VTE (non-IBD-VTE). The study population was comprised of patients seen in 2 tertiary medical centers in Israel between 2000 and 2013. Characteristics of IBD and risk factors for VTE were retrieved from medical charts, and a comprehensive thrombophilia panel was completed in all patients.

RESULTS

Forty-four IBD-VTE cases (27 Crohn's disease) were matched with 127 non-IBD-VTE controls. The majority of VTE had a clear etiology and were considered provoked events. Provoked and unprovoked VTE rates were not different between the 2 groups. Likewise, thrombophilia rates were similar among patients with IBD-VTE and controls (40.9% vs. 53.5%, respectively, P=0.14). However, among patients with unprovoked VTE, thrombophilia rates were significantly lower in the IBD-VTE group compared with controls (42.1% vs. 70.7%, respectively, P=0.03). Among patients with IBD-VTE, an unprovoked event, and negative thrombophilia, 77% had active inflammation at the time of VTE.

CONCLUSION

Thrombophilia rates are similar among patients with IBD-VTE and controls but are less common among patients with unprovoked IBD-VTE. This finding suggests that either inflammation or other novel pathways drive VTE in patients with IBD.

Reference interval of antithrombin, protein C, and protein S activities in healthy adults in Iran, the effect of age, sex, oral contraceptive intake, and menopause

BACKGROUND

Antithrombin (AT), protein C (PC), and protein S (PS) are natural anticoagulant proteins that deficiency in each of them is associated with an increased risk of venous thromboembolism.The overlapping of plasma levels of AT, PC, and PS between healthy individuals and heterozygote carriers poses significant challenges in precise diagnosis. This study aimed to evaluate the effect of most influencing variables on plasma levels of these proteins and propose specific reference intervals to improve the interpretation of the laboratory results.

METHODS

This study was conducted on 1464 individuals who were referred to Massoud medical laboratory, Tehran, Iran, from 2019 to 2020. AT and PC were measured through chromogenic assay and PS plasma level with the clot-based assay. A multivariable linear regression model was performed to evaluate the effect of sex, age, oral contraceptive (OCP) intake, and menopause state. Normal deviate z value was used for different subgroups to justify the need for a separate reference interval.

RESULTS

1200 verified healthy individuals (434 males and 766 females), aged between 18 and 69 years were included in the study. The mean ± SD age of the participants was 39.78 ± 11.79 years. The age-related effects for AT were found in men. In females, increasing age was associated with a rise in AT, PC, and PS plasma levels. No sex difference was found in AT plasma level. OCP-taking is associated with a decrease in AT and an increase in PC plasma levels.

CONCLUSION

This is the largest study ever conducted on healthy individuals in the Iranian population, using specific reference interval results in accurate diagnosis of true AT, PC, and PS deficiency.

The ASH-ASPHO Choosing Wisely Campaign: 5 hematologic tests and treatments to question

Choosing Wisely is a medical stewardship and quality-improvement initiative led by the American Board of Internal Medicine Foundation in collaboration with leading medical societies in the United States. The American Society of Hematology (ASH) has been an active participant in the Choosing Wisely project. In 2019, ASH and the American Society of Pediatric Hematology/Oncology (ASPHO) formed a joint task force to solicit, evaluate, and select items for a pediatric-focused Choosing Wisely list. By using an iterative process and an evidence-based method, the ASH-ASPHO Task Force identified 5 hematologic tests and treatments that health care providers and patients should question because they are not supported by evidence, and/or they involve risks of medical and financial costs with low likelihood of benefit. The ASH-ASPHO Choosing Wisely recommendations are as follows: (1) avoid routine preoperative hemostatic testing in an otherwise healthy child with no previous personal or family history of bleeding, (2) avoid platelet transfusion in asymptomatic children with a platelet count >10 × 10³/μL unless an invasive procedure is planned, (3) avoid thrombophilia testing in children with venous access-associated thrombosis and no positive family history, (4) avoid packed red blood cells transfusion for asymptomatic children with iron deficiency anemia and no active bleeding, and (5) avoid routine administration of granulocyte colony-stimulating factor for prophylaxis of children with asymptomatic autoimmune neutropenia and no history of recurrent or severe infections. We recommend that health care providers carefully consider the anticipated risks and benefits of these identified tests and treatments before performing them.

Establishment of a new protein C detection system based on chromogenic substrate assay and its clinical diagnostic value for deep vein thrombosis

Background

Deficiency of protein C (PC) affects the balance between blood coagulation and fibrinolysis in the human body. Chromogenic‐based assay is recommended as the preferred screening method for detecting PC deficiency. We established a PC detection system based on the chromogenic substrate assay.

Methods

First, a kit for the determination of PC activity in plasma was elaborately developed and its reaction parameters on XL‐3200c were explored. Then, we evaluated its performance and collected specimens to compare the test results obtained with those of the Siemens detection system. Finally, the clinical diagnostic efficacy of this detection system for deep vein thrombosis (DVT) was assessed.

Results

Optimum conditions for PC detection were 0.25–0.1 U/ml protein C activator Protac^® and 2.5–1 mM Pefachrome^®PCa5297. The composition and concentration ranges of buffer substances and stabilizers in the kit were also explored. Satisfactory results were observed in performance evaluation. The test results of the newly built detection system were highly correlated with those of the Siemens detection system (R² = 0.9771 in the control group and R² = 0.9776 in the DVT group), and Bland‐Altman plots also showed high consistency between the two detection systems. In addition, the area under the curve (AUC) of the newly built PC detection system for DVT was 0.888, indicating this system could effectively improve the diagnostic sensitivity and specificity for DVT.

Conclusion

In this study, a sensitive, wide linear range and reliable PC activity detection system were established.

Heritable Thrombophilia in Venous Thromboembolism in Northern Pakistan: A Cross-Sectional Study

BACKGROUND

Venous thromboembolism (VTE) is referred to as formation of clots in a deep vein or lodging of thrombus towards the lungs which could be fatal yet preventable. The risk of developing VTE can be increased by various factors. Where there are innumerable acquired causes, the possibility of inherited thrombophilia cannot be ignored. In view of this, we have evaluated all patients with venous thromboembolism for inherited thrombophilia.

OBJECTIVE

To evaluate the frequencies of antithrombin (AT) deficiency, protein C and S deficiencies, Factor V Leiden, and prothrombin gene mutations in patients harboring venous thromboembolism.

MATERIALS AND METHODS

A study comprising of 880 patients who were presented with manifestations of venous thromboembolism was conducted from July 2016 to June 2017. A blood sample collected from patients was screened for thrombophilia defects encompassing AT, protein C and S deficiencies, Factor V Leiden, and prothrombin gene mutations. All acquired causes of thrombosis were excluded.

RESULTS

Of 880 patients who underwent screening for thrombophilia, 182 patients demonstrated VTE history. Their age ranged from 1 to 58 years. Males constituted a predominant group. About 45 (24.7%) patients had evidence of heritable thrombophilia. Of these, 20 (10.9%) had AT deficiency, 9 (4.9%) had Factor V Leiden mutation, 6 (3.2%) had protein C deficiency, whereas protein S deficiency and prothrombin gene mutation both were found in 5 (2.7%) patients.

CONCLUSION

Our study illustrated the highest frequency of antithrombin deficiency among other investigated thrombophilia defects.

Evaluation of thrombophilia testing in the inpatient setting: A single institution retrospective review

Background

Thrombophilia workup is typically inappropriate in the inpatient setting as testing may be skewed by anticoagulation, acute thrombosis, or acute illness.

Objective

To determine adherence of inpatient thrombophilia testing with institutional guidelines.

Patients and methods

A retrospective study to evaluate thrombophilia testing practices of adult patients who were admitted to Lehigh Valley Hospital at Cedar Crest with either venous thromboembolism or ischemic stroke in 2019. Testing included inherited and acquired thrombophilia. Patient charts were individually reviewed for three measured outcomes: 1) the number of appropriate thrombophilia testing in the inpatient setting; 2) the indications used for thrombophilia testing; 3) the proportion of positive thrombophilia tests with change in clinical management.

Results

201 patients were included in our study. 26 patients (13%) were tested appropriately in accordance with institution guidelines and 175 (87%) patients were tested inappropriately. The most common reason for the inappropriate testing was testing during acute thrombosis. 28 of the 201 patients had positive thrombophilia tests, but the reviewers only noted 7 patients with change in clinical management—involving anticoagulation change.

Conclusion

Our study revealed that a majority of inpatient thrombophilia testing did not follow institutional guidelines for appropriate testing and did not change patient management. These thrombophilia tests are often overutilized and have minimal clinical utility in the inpatient setting.

Thrombophilia testing in the era of direct oral anticoagulants

Venous thromboembolism (VTE) is increasingly recognised in primary and secondary care practice. The arrival of direct oral anticoagulants (DOACs) has made the management of VTE easier and more convenient. Some patients established on DOACs may need screening for underlying thrombophilias as certain thrombophilic conditions are known to confer a higher thrombosis risk, although the guidelines for when and how to test for a thrombophilia, especially in a patient taking a DOAC, are unclear. This literature review aims to examine when thrombophilia screening should take place in a patient already taking a DOAC, the effect of DOACs on thrombophilia tests, and analyse whether DOACs are safe and effective in both inherited and acquired thrombophilias.

Findings from a multicentre, observational study on reproductive outcomes in women with unexplained recurrent pregnancy loss: the OTTILIA registry

STUDY QUESTION

What evaluation and care is offered to women after unexplained recurrent pregnancy loss (RPL) or intra-uterine foetal death (IUFD) and what are the reproductive outcomes?

SUMMARY ANSWER

Women are assessed for thrombophilia and often treated with low-molecular weight heparin (LMWH) and/or low-dose aspirin (ASA).

WHAT IS KNOWN ALREADY

Randomized controlled trials (RCTs) on possible efficacy of heparins and/or aspirin have been inconclusive due to limited power to detect a difference and patient heterogeneity.

STUDY DESIGN, SIZE, DURATION

Prospective multicentre cohort study performed in 12 hospitals in three countries between 2012 and 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All consecutive pregnant women with recurrent PL (≥3 losses or 2 losses in the presence of at least one euploid foetal karyotype) or at least one IUFD. Eligible women may have undergone thrombophilia testing before conception, at the discretion of local providers. The possible assignment of women to treatments (such as LMWH) was not decided a priori but was determined based on the responsible provider's current practice. Aims of the study were: (i) to evaluate factors associated with pregnancy outcome; (ii) to compare clinical management strategies in women with and without a subsequent successful pregnancy; and (iii) to evaluate characteristics of women who may benefit from antithrombotic therapy. A propensity score matching method was used to balance the differences in baseline characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

A matched sample of 265 pregnant women was analysed, with all undergoing thrombophilia screening; 103 out of 119 (86.6%) with and 98/146 (67.1%) without thrombophilia were prescribed with LMWH and/or ASA. Overall, live-births were recorded in 204 cases (77%), PL or IUFD in 61 (23%) pregnancies. Logistic regression showed a significant interaction between thrombophilia and treatment with LMWH (P = 0.03). Findings from sensitivity analysis showed odds ratio (OR) for pregnancy loss in women with inherited or acquired thrombophilia in absence of any treatment was 2.9 (95% CI, 1.4-6.1); the administration of LMWH (with or without ASA) was associated with higher odds of live-birth (OR, 10.6; 95% CI, 5.0-22.3). Furthermore, in women without thrombophilia, the odds of live-birth was significantly and independently associated with LMWH prophylaxis (alone or in association with ASA) (OR, 3.6; 95% CI, 1.7-7.9).

LIMITATIONS, REASONS FOR CAUTION

While the propensity score matching allows us to balance the differences in baseline characteristics, it does not eliminate all confounding.

WIDER IMPLICATIONS OF THE FINDINGS

Antithrombotic prophylaxis during pregnancy may be effective in women with otherwise unexplained PL or IUFD, and even more useful in those with thrombophilia.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by Italian Ministry of Health (Ricerca Corrente 2018-2020). Dr G.P. has received research grant support from Bristol Myers Squibb/Pfizer Alliance, Janssen, Boston Scientific Corporation, Bayer, and Portola and consultant fees from Amgen and Agile Therapeutics. Dr E.G. has received consultant fees from Italfarmaco and Sanofi. All other authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

NCT02385461.

Invited Review: Optimal Management of Upper Extremity DVT: Is Venous Thoracic Outlet Syndrome Underrecognized?

BACKGROUND

UEDVT accounts for approximately 10% of all cases of deep vein thrombosis. In the most widely referenced general review of deep vein thrombosis (DVT the American Academy of Chest Physicians essentially recommend that upper extremity DVT (UEDVT) essentially be treated identically to that of lower extremity DVT, with anticoagulation being the default therapy. Unfortunately, the medical literature does not well differentiate between DVT in the arm and the leg, and does not emphasize the effects of the costoclavicular junction (CCJ) and the lack of effect of gravity, to the point where UEDVT due to extrinsic bony compression at the CCJ is classified as "primary."

METHODS

Comprehensive literature review, beginning with both Medline and Google Scholar searches in addition to collected references, then following relevant citations within the initial manuscripts studied. Both surgical and medical journals were explored RESULTS: It is proposed that effort thrombosis be classified as a secondary cause of UEDVT, limiting the definition of primary to that which is truly idiopathic. Other causes of secondary UEDVT include catheter- and pacemaker-related thrombosis (the most common cause, but often asymptomatic), thrombosis related to malignancy and hypercoagulable conditions, and the rare case of thrombosis due to compression of the vein by a focal malignancy or other space-occupying lesion. In true primary UEDVT and in those secondary cases where no mechanical cause is present or can be corrected, anticoagulation remains the treatment of choice, usually for three months or the duration of a needed catheter. However, evidence suggests that many cases of effort thrombosis are likely missed by a too-narrow adherence to this protocol.

CONCLUSIONS

Because proper treatment of effort thrombosis drops the long-term symptomatic status rate from 50% to almost zero and these are healthy patients with a long lifespan ahead, it is proposed that a more aggressive attitude toward thrombolysis be followed in any patient who has a reasonable degree of suspicion for venous thoracic outlet syndrome.

The ASH-ASPHO Choosing Wisely Campaign: 5 hematologic tests and treatments to question

Choosing Wisely is a medical stewardship and quality-improvement initiative led by the American Board of Internal Medicine Foundation in collaboration with leading medical societies in the United States. The American Society of Hematology (ASH) has been an active participant in the Choosing Wisely project. In 2019, ASH and the American Society of Pediatric Hematology/Oncology (ASPHO) formed a joint task force to solicit, evaluate, and select items for a pediatric-focused Choosing Wisely list. By using an iterative process and an evidence-based method, the ASH-ASPHO Task Force identified 5 hematologic tests and treatments that health care providers and patients should question because they are not supported by evidence, and/or they involve risks of medical and financial costs with low likelihood of benefit. The ASH-ASPHO Choosing Wisely recommendations are as follows: (1) avoid routine preoperative hemostatic testing in an otherwise healthy child with no previous personal or family history of bleeding, (2) avoid platelet transfusion in asymptomatic children with a platelet count 10 × 10³ /μL unless an invasive procedure is planned, (3) avoid thrombophilia testing in children with venous access-associated thrombosis and no positive family history, (4) avoid packed red blood cells transfusion for asymptomatic children with iron deficiency anemia and no active bleeding, and (5) avoid routine administration of granulocyte colony-stimulating factor for prophylaxis of children with asymptomatic autoimmune neutropenia and no history of recurrent or severe infections. We recommend that health care providers carefully consider the anticipated risks and benefits of these identified tests and treatments before performing them.

Thrombophilia, Inflammation, and Recurrent Pregnancy Loss: A Case-Based Review

Recurrent pregnancy loss (RPL) is defined as the loss of two or more pregnancies and is often multifactorial with the majority of miscarriages being due to aneuploidy and anatomic or physiological abnormalities. However, inherited or acquired thrombophilias have also been associated with RPL, albeit inconsistently. While inherited thrombophilias, such as factor V Leiden and prothrombin gene mutation, are relatively prevalent in women with RPL compared with the general population, a causal link has yet to be definitively established. Recently, systemic inflammation, as measured by high-sensitivity C-reactive protein, has also been hypothesized to play a role in infertility. Based on limited prospective trial data, antithrombotic therapy and antiplatelet agents have been proposed as possible tools for the prevention of RPL. Because of the multifactorial nature of RPL and infertility, various clinicians, as obstetricians and gynecologists, endocrinologists, hematologists, or vascular medicine specialists, may be requested to counsel these women. This, together with evidence gaps, frequently leads to distinctly different diagnostic and therapeutic recommendations, especially regarding thrombophilia testing and treatment. Using four case vignettes in this review, we critically appraise the literature and highlight how two clinicians from different subspecialties approach the relationship between RPL, inflammation, and thrombophilia.

Prevention of Venous Thromboembolism in Gynecologic Surgery: ACOG Practice Bulletin, Number 232

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are collectively referred to as "venous thromboembolic events" (VTE). Despite advances in prophylaxis, diagnosis, and treatment, VTE remains a leading cause of cost, disability, and death in postoperative and hospitalized patients (1, 2). Beyond the acute sequelae of leg pain, edema, and respiratory distress, VTE may result in chronic conditions, including postthrombotic syndrome (3), venous insufficiency, and pulmonary hypertension. This Practice Bulletin has been revised to reflect updated literature on the prevention of VTE in patients undergoing gynecologic surgery and the current surgical thromboprophylaxis guidelines from the American College of Chest Physicians (4). Discussion of gynecologic surgery and chronic antithrombotic therapy is beyond the scope of this document.

Trends of Ordering Hypercoagulability Work-Up at an Academic Medical Center

Background

Venous thromboembolism is a significant clinical event, with an annual incidence of 1–2 per 1000 population. Risk factors include recent surgery, prolonged immobility, oral contraceptive use, and active cancer. Inherited risks include protein C and S deficiencies, antithrombin deficiency, factor V Leiden mutation and prothrombin. These factors can be tested to guide therapy, but current evidence suggests that testing for inherited thrombophilia is not recommended in most inpatient settings. In the era of high value care, hypercoagulable testing for VTE creates a financial burden for the hospital and patients. We performed a retrospective chart review of hypercoagulable orders on VTE patients at our institution.

Methods

Institutional Review Board approval was obtained. A total of 287 adult patients admitted over a 3-month period with the diagnosis of VTE were included. Patients were identified via ICD-10 codes and data were collected from electronic medical records. Patient characteristics, provoked versus unprovoked VTE, and relative contraindications for hypercoagulability work-up were analyzed. Our primary outcome was to assess the appropriateness of thrombophilia testing in VTE patients based on screening guidelines. Our secondary outcome was to analyze the cost burden of ordering these tests.

Results

A total of 287 patients were included in our data analysis. Patient risk factors for VTE were malignancy, previous DVT, immobilization, surgery 3 months prior, and central line placement. Fifty-seven of 287 patients had at least one hypercoagulable test ordered during hospitalization which did not adhere to guidelines. Misuse of testing occurred during active thrombosis, active anticoagulation, presence of risk factors, first episode of VTE, and malignancy. The cost of ordering these 5 thrombophilia tests totaled over $40,000.

Conclusion

In our study, numerous patients were tested without compliance to standard recommendations, which created financial and value-based burdens on our health care system. Increased awareness among clinicians is thus warranted to ensure high value care.

The Pathophysiology of Hypercoagulability and Infertility

Alongside an interplay of a multitude of factors, attainment of a favorable pregnancy outcome is predicated on successful implantation, which in itself is a complex process anchored by balanced interchange with the hemostatic system. Among other etiologies, failure of implantation can result in infertility, and lead affected couples to consider assisted reproductive technology (ART) in an effort to fulfill their desire for procreation. Given the critical role of the hemostatic system in the process of implantation, documentation of a hypercoagulable state during controlled ovarian stimulation in the context of in vitro fertilization, as well as the potential association of its derangement in the setting of thrombophilia, with infertility, ART, ovarian hyperstimulation syndrome, and failure of implantation are explored. Additionally, current evidence addressing the relationship between ART and thromboembolism is examined, as is the role of therapy with heparin and aspirin to decrease thrombotic risk and improve ART-related pregnancy outcomes. Evidence-based recommendations from relevant professional societies are summarized.