Rivaroxaban vs warfarin in high-risk patients with antiphospholipid syndrome

Recent advances in understanding, diagnosing and treating venous thrombosis

Focusing on the current state of the art, this article (a) describes recent advances in the understanding of the pathogenesis of venous thromboembolism (VTE), (b) discusses current approaches for the prevention, diagnosis and treatment of VTE, (c) outlines the role of aspirin for VTE prevention and treatment, and (d) highlights the unmet needs in VTE management and describes novel approaches to address them.

16th International Congress on Antiphospholipid Antibodies Task Force Report on Antiphospholipid Syndrome Treatment Trends

Antiphospholipid syndrome (APS), an acquired autoimmune thrombophilia, is characterised by thrombosis and/or pregnancy morbidity in association with persistent antiphospholipid antibodies. The 16th International Congress on Antiphospholipid Antibodies Task Force on APS Treatment Trends reviewed the current status with regard to existing and novel treatment trends for APS, which is the focus of this Task Force report. The report addresses current treatments and developments since the last report, on the use of direct oral anticoagulants in patients with APS, antiplatelet agents, adjunctive therapies (hydroxychloroquine, statins and vitamin D), targeted treatment including rituximab, belimumab, and anti-TNF agents, complement inhibition and drugs based on peptides of beta-2-glycoprotein I. In addition, the report summarises potential new players, including coenzyme Q10, adenosine receptor agonists and adenosine potentiation. In each case, the report provides recommendations for clinicians, based on the current state of the art, and suggests a clinical research agenda. The initiation and development of appropriate clinical studies requires a focus on devising suitable outcome measures, including a disease activity index, an optimal damage index, and a specific quality of life index.

Anti-phospholipid syndrome leading to digital ischaemia and rare organ complications in systemic sclerosis and related disorders

Antiphospholipid syndrome (APS) is an acquired, autoimmune thrombophilia that can occur as a primary disorder (with no associated disease) or secondary to infection, medication usage and autoimmune rheumatic diseases (ARDs). The association between APS and systemic lupus erythematosus (SLE) is well established, and practicing rheumatologists check for APS antibodies in the routine assessment of SLE, particularly if clinical features such as thrombotic events or pregnancy loss are present. APS secondary to systemic sclerosis (SSc)-related disorders is less widely recognised and easily overlooked. We describe 5 cases that highlight the varied breadth of clinical manifestations of APS in the context of SSc and related disorders. These cases range from uncomplicated Raynaud's phenomenon, digital ulceration/necrosis, critical digital ischaemia/gangrene and rare internal organ complications of APS in SSc-spectrum disorders. To our knowledge, our cases include the first reported case of secondary APS contributing to digital necrosis in the context of RACAND syndrome (Raynaud's phenomenon, anti-centromere antibodies and necrosis of the digits) and the first reported case of secondary APS in SSc causing posterior reversible encephalopathy syndrome (PRES). The case series is accompanied by a comprehensive review of the literature relevant to each case. Rheumatologists should be alert to the possibility of APS in SSc-spectrum disorders and should routinely check APS antibodies in all patients at diagnosis, and again later in the disease course if new features emerge that could indicate the presence of thrombotic events or other recognised APS manifestations. Key points • APS should be considered in all patients with digital ischaemic symptoms. • APS may be an important driver of SSc-related digital ulceration/necrosis. • Identification of SSc-associated APS opens up new therapeutic options for acute management and secondary prevention.

Treatment of antiphospholipid syndrome

Antiphospholipid syndrome (APS) is the most common acquired thrombophilia. The clinical manifestations of APS are mainly vascular thrombosis (venous and/or arterial) and/or recurrent pregnancy morbidity with the concomitant persistent presence of antiphospholipid antibodies (aPL). Therefore, the goals of the treatment of patients with APS are reducing the pregnancy morbidity and/or the prevention of thrombotic events during the follow-up. Optimal treatment of APS has long been discussed, due to the heterogeneity of the clinical manifestations and the consequent plurality in the medical specialties involved in managing this condition. This review summarizes the available evidence on primary thromboprophylaxis in aPL-positive individuals with no prior thrombotic events, secondary prophylaxis in patients with positive history for thrombotic events, the management of refractory or difficult cases and the current strategies for the management of APS during pregnancy.

Comprehensive review of the impact of direct oral anticoagulants on thrombophilia diagnostic tests: Practical recommendations for the laboratory

There is a laboratory and clinical need to know the impact of direct oral anticoagulants (DOACs) on diagnostic tests to avoid misinterpretation of results. Although the regulatory labelling documents provide some information about the influences of each DOAC on diagnostic tests, these are usually limited to some of the most common tests and no head to head comparison is available. In this paper, we report the impact of DOACs on several thrombophilia tests, including assessment of antithrombin, protein S and protein C activity assays, detection of activated protein C resistance and assays used for lupus anticoagulant. Results are compared and discussed with data obtained from literature. The final goal of this comprehensive review is to provide practical recommendations for laboratories to avoid misdiagnosis due to oral direct factor Xa (FXa) or IIa (FIIa) inhibitors. Overall, oral direct FXa (apixaban, betrixaban, edoxaban and rivaroxaban) and FIIa (dabigatran) antagonists may affect clot-based thrombophilia diagnostic tests resulting in false-positive or false-negative results. An effect on FIIa-based thrombophilia diagnostic tests is observed with dabigatran but not with anti-FXa DOACs and conversely for FXa-based thrombophilia diagnostic tests. No impact was observed with antigenic/chromogenic methods for the assessment of protein S and C activity. In conclusion, interpretation of thrombophilia diagnostic tests results should be done with caution in patients on DOACs. The use of a device/chemical compound able to remove or antagonize the effect of DOACs or the development of new diagnostic tests insensitive to DOACs should be considered to minimize the risk of false results.

Antiphospholipid syndrome in pediatric patients

PURPOSE OF REVIEW

The purpose of this review is to summarize the diagnosis and management of the antiphospholipid syndrome (APS) in children.

RECENT FINDINGS

APS is a rare, acquired autoimmune systemic disease that can result in significant morbidity in children related to vascular thrombosis. The diagnosis and management of APS in children can be challenging due to a lack of validated diagnostic criteria and the rarity of the disease. In addition, many healthy children have transient circulating antiphospholipid antibodies without thrombotic complications. Nevertheless, epidemiological studies suggest that APS represents a greater relative proportion of thrombotic disease in children than it does in adults. Management of pediatric APS is largely inferred from adult data despite unique characteristics of pediatric APS. The current recommendations include long-term anticoagulation, which can be problematic in young, active individuals. There is little data on potential benefits of nonantithrombotic therapy in the management of pediatric APS.

SUMMARY

Data on pediatric APS are limited, but evidence suggests that using current available diagnostic testing is valuable and, until further evidence is available, treating thrombotic complications with heparins or warfarin should be standard of care.

Cardiovascular Disease in Antiphospholipid Syndrome

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Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by venous, arterial or microvascular thrombosis or obstetric events in the presence of persistently positive antiphospholipid antibodies and constitutes a major cause of cardiovascular events in young people. Τhis review highlights the pathophysiology of cardiovascular complications in patients with APS and possible treatment options.

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Patients with APS have endothelial dysfunction, accelerated endothelial proliferation and intimal hyperplasia, atherogenesis, platelet activation, inflammatory products secretion and coagulation-fibrinolytic dysregulation. Cardiovascular complications include accelerated atherosclerosis, acute coronary syndrome, Libman-Sacks endocarditis, cardiomyopathy and venous, arterial or intracardiac thrombi. Moreover, pulmonary hypertension and peripheral microvascular dysfunction are common findings.

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Management of these patients is not well documented. The role of primary thrombosis prevention remains controversial in individuals with positive antiphospholipid antibodies. Treatment of traditional cardiovascular risk factors according to current guidelines for the prevention of cardiovascular disease in the general population is recommended for primary prevention of APS. Anticoagulation therapy with unfractionated or low-molecular-weight heparin overlapped with a vitamin K antagonist remains the mainstay of the treatment for APS patients with venous thrombosis, whereas direct oral anticoagulants are not yet recommended. Data are scarce regarding the secondary arterial thrombosis prevention and it is not clear whether dual or triple antithrombotic therapy is necessary. To date, it is recommended to follow current guidelines for the management of acute coronary syndrome in the general population. New treatment targets are promising options for patients with catastrophic APS.

[Lupus and thrombophilia : Antiphospholipid syndrome]

Even early on thromboembolic events were observed in patients with systemic lupus erythematosus (SLE) until the antiphospholipid syndrome (APS) was described in the 1980s as an independent disorder. The APS is a systemic autoimmune disease often overlapping with SLE in which antiphospholipid autoantibodies, including lupus anticoagulant, can cause a hypercoagulation state, which clinically by definition is manifested as arterial and venous occlusions or pregnancy complications. The pathophysiology has not yet been entirely delineated and the clinical spectrum of associated concomitant manifestations is large. As the mortality is increased with SLE and simultaneous APS, focused diagnostics and risk assessment are indispensable. According to the recently published recommendations of the European League Against Rheumatism the therapeutic strategy comprises individualized secondary prevention of thromboembolic complications by means of anticoagulation (with unaltered importance of vitamin K antagonists) and thrombocyte aggregation inhibition, usually lifelong. Statins and antimalarial drugs are recommended for vascular protection while immunosuppressive treatment has not so far been sufficiently proven for APS but remains the subject of current research.

A Review of the Incidence Diagnosis and Treatment of Spontaneous Hemorrhage in Patients Treated with Direct Oral Anticoagulants

Anticoagulation carries a tremendous therapeutic advantage in reducing morbidity and mortality with venous thromboembolism and atrial fibrillation. For over six decades, traditional anticoagulants like low molecular weight heparin and vitamin K antagonists like warfarin have been used to achieve therapeutic anticoagulation. In the past decade, multiple new direct oral anticoagulants have emerged and been approved for clinical use. Since their introduction, direct oral anticoagulants have changed the landscape of anticoagulants. With increasing indications and use in various patients, they have become the mainstay of treatment in venous thromboembolic diseases. The safety profile of direct oral anticoagulants is better or at least similar to warfarin, but several recent reports are focusing on spontaneous hemorrhages with direct oral anticoagulants. This narrative review aims to summarize the incidence of spontaneous hemorrhage in patients treated with direct oral anticoagulants and also offers practical management strategies for clinicians when patients receiving direct oral anticoagulants present with bleeding complications.

Direct oral anticoagulants versus vitamin K antagonists in antiphospholipid syndrome: A meta-analysis

BACKGROUND

Anticoagulant treatment is recommended in patients with thrombosis and antiphospholipid syndrome (APS). Conflicting results have been reported on the role of direct oral anticoagulants (DOACs) in these patients. We performed a meta-analysis of randomized controlled trials (RCTs) focused on this issue.

METHODS

We searched MEDLINE and EMBASE for RCTs comparing DOACs and vitamin K antagonists (VKAs) for secondary thromboprophylaxis in patients with thrombotic APS. The primary objective was to assess the efficacy of DOACs compared to VKAs to prevent recurrence of thromboembolic events. Risk difference (RD) was reported as weighted RD according to Mantel-Haenszel random-effect method.

RESULTS

Three RCTs (426 patients) were included, all comparing rivaroxaban with VKAs. The proportion of recurrences (either arterial or venous) was higher among rivaroxaban patients when compared with those receiving VKAs (9.5% vs 2.8%; RD 6%, 95% CI, -0.05 - 0.18, p=0.29), although non-statistically significant. In patients with an arterial index event, thromboembolic recurrences were more frequent in those treated with rivaroxaban compared to those treated with VKAs (25% vs 6.2%; RD 19%, 95% CI, 0.04 - 0.33; p =0.01; I² 49%). In triple aPL positive patients, rivaroxaban showed higher rates of thromboembolic recurrences compared with VKAs (12% vs 3%; RD 9%, 95% CI, 0.02 - 0.15; p= 0.01; I² 13%). Non-statistically significant differences were observed in major bleeding events or mortality.

CONCLUSIONS

The use of rivaroxaban in APS patients is associated with an increased rate of thromboembolic recurrences compared to VKAs, at least in those with arterial index event or triple aPL positivity.

Recurrent thrombosis in patients with antiphospholipid antibodies and an initial venous or arterial thromboembolic event: A systematic review and meta-analysis

BACKGROUND

Patients with antiphospholipid antibodies (aPL) and thromboembolism (TE) are at risk for recurrent TE. Few studies, however, distinguish patients based on the initial event.

OBJECTIVES

We performed a systematic review and meta-analysis to investigate patients with aPL and venous TE (VTE), provoked or unprovoked, and patients with arterial TE (ATE).

PATIENTS/METHODS

We conducted searches in PubMed, CINAHL, Cochrane, and EMBASE. Inclusion criteria were prospective trials or cohort studies investigating patients with aPL and ATE or VTE. Excluded studies did not provide estimated recurrence rates, did not specify whether the incident event was ATE or VTE, included patients with multiple events, or included <10 patients. Two-year summary proportions were estimated using a random effects model.

RESULTS

Ten studies described patients with VTE, 2 with ATE, and 5 with VTE or ATE. The 2-year proportion for recurrent TE in patients with VTE who were taking anticoagulant therapy was 0.054 (95% confidence interval [CI], 0.037-0.079); the 2-year proportion for patients not taking anticoagulant therapy was 0.178 (95% CI, 0.150-0.209). Most studies did not distinguish whether VTE were provoked or unprovoked. The 2-year proportion for recurrent TE in patients with ATE who were taking anticoagulant therapy was 0.220 (95% CI, 0.149-0.311); the 2-year proportion for patients taking antiplatelet therapy was 0.216 (95% CI, 0.177-0.261).

CONCLUSIONS

Patients with aPL and ATE may benefit from a different antithrombotic approach than patients with aPL and VTE. Prospective studies with well-defined cohorts with aPL and TE are necessary to determine optimal antithrombotic strategies.

Management of cardiovascular disease in patients with systemic lupus erythematosus

INTRODUCTION

SLE is increasingly recognized as an important risk factor for cardiovascular disease. Premature CAD and several other cardiac manifestations are resulting in significant morbidity and premature death among young and older adults. There is a considerable unmet need for developing specific guidelines toward the primary and secondary prevention of cardiovascular disease in SLE patients.

AREAS COVERED

The authors describe the prevalence of various cardiovascular manifestations, associated with traditional and lupus-specific risk factors. They summarize the evidence behind various nonpharmacological and pharmacological options such as cardiac medications, antimalarials, anti-inflammatory, and immunosuppressant medications.

EXPERT OPINION

There is considerable literature claiming that the traditional Framingham score used to calculate the risk in the general population would not clearly predict the 10-year risk among SLE patients as they do not include lupus-specific risk factors such as accelerated inflammation, immunometabolic changes, thrombosis, vasospasm, vasculitis, and endothelial dysfunction into account. Identifying potential risk factors among SLE patients and treating hyperlipidemia regardless of their risk scores may be the first step in reducing mortality. Blocking lupus-specific inflammatory pathways by targeting validated biomarkers of pathogenesis has great future potential and more studies are needed on their cardiovascular benefits.

Use of direct oral anticoagulants in patients with thrombotic antiphospholipid syndrome: Guidance from the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis

Clarity and guidance is required with regard to the use of direct oral anticoagulants in antiphospholipid syndrome (APS) patients, within the confines of the recent European Medicines Agency recommendations, discrepant recommendations in other international guidelines and the limited evidence base. To address this, the Lupus Anticoagulant/Antiphospholipid Antibodies Scientific and Standardization Committee (SSC) chair and co-chairs together with SSC Control of Anticoagulation members propose guidance for healthcare professionals to help them manage APS patients. Uncertainty in this field will be addressed. This guidance will also serve as a call and focus for research.

Management of acute pulmonary embolism 2019: what is new in the updated European guidelines?

Pulmonary embolism (PE) is the third most frequent acute cardiovascular syndrome. Annual PE incidence and PE-related mortality rates rise exponentially with age, and consequently, the disease burden imposed by PE on the society continues to rise as the population ages worldwide. Recently published landmark trials provided the basis for new or changed recommendations included in the 2019 update of the European Society of Cardiology Guidelines (developed in cooperation with the European Respiratory Society). Refinements in diagnostic algorithms were proposed and validated, increasing the specificity of pre-test clinical probability and D-dimer testing, and thus helping to avoid unnecessary pulmonary angiograms. Improved diagnostic strategies were also successfully tested in pregnant women with suspected PE. Non-vitamin K antagonist oral anticoagulants (NOACs) are now the preferred agents for treating the majority of patients with PE, both in the acute phase (with or without a brief lead-in period of parenteral heparin or fondaparinux) and over the long term. Primary reperfusion is reserved for haemodynamically unstable patients. Besides, the 2019 Guidelines endorse multidisciplinary teams for coordinating the acute-phase management of high-risk and (in selected cases) intermediate-risk PE. For normotensive patients, physicians are advised to include the assessment of the right ventricle on top of clinical severity scores in further risk stratification, especially if early discharge of the patient is envisaged. Further important updates include guidance (1) on extended anticoagulation after PE, taking into account the improved safety profile of NOACs; and (2) on the overall care and follow-up of patients who have suffered PE, with the aim to prevent, detect and treat late sequelae of venous thromboembolism.

Artery of Percheron Infarct: A Rare Presentation of Acute Ischemic Stroke in a High-Risk Antiphospholipid Syndrome Patient

Artery of Percheron (AOP) is an abnormal variant of the arterial supply of the thalamus. AOP occlusion can lead to bilateral thalamic and rostral midbrain infarct presenting as memory loss, fluctuating levels of consciousness, and altered mental status. A 43-year-old woman with a history of antiphospholipid syndrome (APS), managed on dabigatran, presented with acute confusion and drowsiness. She had slurred and slowed speech, disorientation in time and place, left-sided facial droop, decreased power of the left side (4/5), and was unable to walk due to generalized weakness. Labs showed a prolonged prothrombin time and activated partial thromboplastin time, positive lupus anticoagulant, anti-cardiolipin, beta-2 glycoprotein, anti-nuclear and anti-dsDNA antibodies. Contrast-enhanced CT perfusion showed ischemic changes in the bilateral thalami, suggesting infarct along the AOP territory. AOP infarcts are scarce and the presenting complaints are unusual of cerebrovascular accidents. It requires a high index of suspicion to detect. There are no other reports in the literature of patients with APS presenting with an AOP infarct. Considering the lack of evidence, we recommend against the use of newer oral anticoagulants (NOACs) for secondary prevention of vascular events in patients with triple-positive APS.

Management of anticoagulant-refractory thrombotic antiphospholipid syndrome

Lifelong anticoagulation with warfarin or alternative vitamin K antagonist is the standard anticoagulant treatment for thrombotic antiphospholipid syndrome. Anticoagulant-refractory thrombotic antiphospholipid syndrome can be broadly defined as breakthrough thrombosis while on standard oral anticoagulation treatment and its management is a major challenge given the serious nature of the thrombotic disease observed, which has become refractory to oral anticoagulation. The factors (genetic and cellular) that cause anticoagulant-refractory thrombotic antiphospholipid syndrome are now better understood. However, efforts to use this greater understanding have not yet transformed the capacity to treat it successfully in many patients. In this Viewpoint, we review the factors that are likely to be contributing to the cause of this syndrome and consider how they might be modified or inhibited. We also discuss management, including general strategies to minimise thrombotic risk, intensification of anticoagulation, addition of an antiplatelet agent, adjunctive treatment for thrombosis, immunomodulatory therapy, complement inhibition, vascular options, and future potential therapeutic targets.

Clinical Utilization and Cost of Thrombophilia Testing in Patients with Venous Thromboembolism

Introduction  Testing for inherited and acquired thrombophilias adds to the cost of care of patients with venous thromboembolism (VTE), though results may not influence patient management.

Methods  This is a single-center, retrospective study conducted at Emory University Hospitals from January to December 2015 to (1) determine the pattern of thrombophilia testing in patients with VTE, (2) study the impact of results of thrombophilia testing on clinical decision-making, and (3) determine the direct costs of thrombophilia testing in patients with VTE.

Results  Of the 266 eligible patients, 189 (71%) underwent testing; 51 (26.9%) tested positive and the results impacted management in 32 (16.9%) of tested patients. Patient undergoing testing were more likely to be younger than 40 years (30.9 vs. 18.2%), have had prior pregnancy loss (9.0 vs. 0%), or known family history of hypercoagulability (24.9 vs. 10.4%), and were less likely to have had provoked VTE (37 vs. 79.2%). The most common thrombophilias tested were antiphospholipid syndrome (60.1%), factor V Leiden (59.7%), and prothrombin gene mutation (57.5%). Direct costs of thrombophilia testing were $2,364.32 per patient, $12,331.55 to diagnose 1 positive, and $19,653.41 per patient-management affected.

Conclusion  We noted significant variability in selection of patients and panel of tests, sparse utilization of test results in patient management, but high cost associated with thrombophilia testing in patients with VTE. With guidelines advocating selective use of thrombophilia testing and attention to potential impact of test results in patient management, we propose the need for measures at institutional levels to improve test-ordering practices.

Pulmonary embolism: update on management and controversies

Pulmonary embolism is a common and potentially fatal cardiovascular disorder that must be promptly diagnosed and treated. The diagnosis, risk assessment, and management of pulmonary embolism have evolved with a better understanding of efficient use of diagnostic and therapeutic options. The use of either clinical probability adjusted or age adjusted D-dimer interpretation has led to a reduction in diagnostic imaging to exclude pulmonary embolism. Direct oral anticoagulation therapies are safe, effective, and convenient treatments for most patients with acute venous thromboembolism, with a lower risk of bleeding than vitamin K antagonists. These oral therapeutic options have opened up opportunities for safe outpatient management of pulmonary embolism in selected patients. Recent clinical trials exploring the use of systemic thrombolysis in intermediate to high risk pulmonary embolism suggest that this therapy should be reserved for patients with evidence of hemodynamic compromise. The role of low dose systemic or catheter directed thrombolysis in other patient subgroups is uncertain. After a diagnosis of pulmonary embolism, all patients should be assessed for risk of recurrent venous thromboembolism to guide duration of anticoagulation. Patients with a venous thromboembolism associated with a strong, transient, provoking risk factor can safely discontinue anticoagulation after three months of treatment. Patients with an ongoing strong risk factor, such as cancer, or unprovoked events are at increased risk of recurrent events and should be considered for extended treatment. The use of a risk prediction score can help to identify patients with unprovoked venous thromboembolism who can benefit from extended duration therapy. Despite major advances in the management of pulmonary embolism, up to half of patients report chronic functional limitations. Such patients should be screened for chronic thromboembolic pulmonary hypertension, but only a small proportion will have this as the explanation of their symptoms. In the remaining patients, future studies are needed to understand the pathophysiology and explore interventions to improve quality of life.

Cerebral venous thrombosis in women of childbearing age: diagnosis, treatment, and prophylaxis during a future pregnancy

Sex-specific risk factors for cerebral venous thrombosis (CVT) in women include oral contraceptives, pregnancy, puerperium, and hormone replacement therapy. The acute treatment of CVT is anticoagulation using therapeutic doses of low molecular weight heparin, which is also the preferred treatment in the post-acute phase in pregnancy and during breastfeeding. In patients with imminent brain herniation decompressive surgery is probably life-saving. A medical history of CVT alone is not a contraindication for future pregnancies. The optimal dosage of low molecular weight heparin as thrombosis prophylaxis during future pregnancies after a history of venous thrombosis including CVT is the topic of an ongoing trial.

A glimpse into the history of description of the antiphospholipid syndrome

Prior to 1983, several landmark reports prepared the stage for a detailed description of the Antiphospholipid (Hughes) syndrome (APS). Formerly depicted as lupus-like, APS exhibits a wide spectrum of symptoms that overlap with Sjogren's, Hashimoto, and other autoimmune diseases. In this review, we take a glimpse into the history of description of APS, discussing the events that led to its recognition as one of the most common autoimmune diseases and the enormous impact of that recognition in the rheumatology field.

Lupus 2020

Klassifikation 2020 Die neuen ACR/EULAR-Klassifikationskriterien für den systemischen Lupus erythematodes (SLE) stellen einen wichtigen Beitrag zur Optimierung klinischer Studien und eine Hilfestellung zur Diagnostik dar. So kann ein SLE erst als solcher klassifiziert werden, wenn antinukleäre Antikörper (ANA) ab einer Titerhöhe von 1:80 unabhängig vom Fluoreszenzmuster nachgewiesen werden. Sind ANA nachgewiesen, erhalten Lupus-spezifische Symptome und serologische Auffälligkeiten eine unterschiedliche Wichtung für die Klassifikation.

Therapie 2020 Mit der Überarbeitung der EULAR-Empfehlungen zum Management des SLE sowie der Lupusnephritis und des Antiphospholipid-Syndroms stehen nun wichtige neue Therapieprinzipien zur Verfügung. So sollte jede Lupus-Therapie ganz im Sinne eines Treat-to-Target-Ansatzes das Ziel der Remission verfolgen. Dies dient der Sicherung des Langzeitüberlebens, der Reduktion von Schaden sowie der Verbesserung von Lebensqualität. Erreicht werden diese Ziele durch konsequente Therapie auf Basis einer regelmäßigen Evaluation der Krankheitsaktivität. Alle Patienten sollen bei Abwesenheit von Kontraindikationen Antimalariamittel erhalten. Bei unzureichendem Ansprechen auf Antimalariamittel bzw. organgefährdende Manifestationen werden Steroidpulse (über wenige Tage) sowie der frühzeitige Einsatz von Immunsuppressiva (IM) und Biologika wie Belimumab und Rituximab (off-label) empfohlen.

Direct oral anticoagulant adsorption: Impact on lupus anticoagulant testing-Review of the literature and evaluation on spiked and patient samples

BACKGROUND

Direct oral anticoagulants (DOACs) interfere with lupus anticoagulant (LAC) testing. DOAC-Stop (D-S) represents a preanalytical strategy to cope with this issue.

OBJECTIVES

To assess D-S's ability to remove DOACs from plasma and overcome DOAC interference in LAC assays and to evaluate D-S's applicability in a representative patient cohort with routine LAC request.

METHODS

Apixaban (30-933 ng/mL), edoxaban (31-1060 ng/mL), rivaroxaban (35-1020 ng/mL), and dabigatran (20-360 ng/mL) were spiked to normal plasma. Aliquots were treated with D-S or untreated before DOAC and LAC testing. Patient samples containing DOAC (n = 43), vitamin K antagonists (n = 25), heparins (n = 21), or no anticoagulants (n = 63) were tested for LAC before and after D-S.

RESULTS

Spiking experiments revealed false-positive LAC from low concentrations of DOACs except for apixaban. Following D-S, DOAC levels were below lower limits of quantification, except for apixaban at the highest concentration, and no false-positive LAC was obtained. DOAC levels were below lower limits of quantification after D-S in 39/43 DOAC-containing patient samples. For 23/29 LAC-positive DOAC-containing samples, LAC tests became negative after D-S, whereas 3/6 samples remaining positive were from patients with (high probability for) antiphospholipid syndrome. In the non-DOAC-treated groups, LAC changed from positive to negative in 10 and vice versa in 2 cases.

CONCLUSIONS

D-S limits DOAC interference in LAC assays. DOAC concentration measurement should be performed in D-S treated samples because incomplete removal may occur. Applying D-S to vitamin K antagonist-containing, heparin-containing, or not-anticoagulated samples may lead to erroneous LAC results. Therefore, D-S should only be used in plasma from DOAC-treated patients.

Safety of dabigatran etexilate for the secondary prevention of venous thromboembolism in children

This open-label, single-arm, prospective cohort trial is the first phase 3 safety study to describe outcomes in children treated with dabigatran etexilate for secondary venous thromboembolism (VTE) prevention. Eligible children aged 12 to <18 years (age stratum 1), 2 to <12 years (stratum 2), and >3 months to <2 years (stratum 3) had an objectively confirmed diagnosis of VTE treated with standard of care (SOC) for ≥3 months, or had completed dabigatran or SOC treatment in the DIVERSITY trial (NCT01895777) and had an unresolved clinical thrombosis risk factor requiring further anticoagulation. Children received dabigatran for up to 12 months, or less if the identified VTE clinical risk factor resolved. Primary end points included VTE recurrence, bleeding events, and mortality at 6 and 12 months. Overall, 203 children received dabigatran, with median exposure being 36.3 weeks (range, 0-57 weeks); 171 of 203 (84.2%) and 32 of 203 (15.8%) took capsules and pellets, respectively. Overall, 2 of 203 children (1.0%) experienced on-treatment VTE recurrence, and 3 of 203 (1.5%) experienced major bleeding events, with 2 (1.0%) reporting clinically relevant nonmajor bleeding events, and 37 (18.2%) minor bleeding events. There were no on-treatment deaths. On-treatment postthrombotic syndrome was reported for 2 of 162 children (1.2%) who had deep vein thrombosis or central-line thrombosis as their most recent VTE. Pharmacokinetic/pharmacodynamic relationships of dabigatran were similar to those in adult VTE patients. In summary, dabigatran showed a favorable safety profile for secondary VTE prevention in children aged from >3 months to <18 years with persistent VTE risk factor(s). This trial was registered at www.clinicaltrials.gov as #NCT02197416.

Fixed-dose three-factor prothrombin complex concentrates is safe and effective in warfarin reversal

BACKGROUND

Reversal of warfarin with prothrombin complex concentrates (PCC) is required in cases of significant bleeding or need for urgent surgery. A weight-based regimen is commonly, but a fixed-dose approach is also feasible with clinically equivalent outcomes. The purpose of this audit is to review the clinical and laboratory outcomes of patients treated in our centre where fixed-dose PCC is used for warfarin reversal.

OBJECTIVES

The primary objective was to evaluate the post-reversal INR. Secondary objectives were the proportion of patients requiring repeat PCC and 30-day complication rates (death, haemorrhage and thrombosis). A subgroup analysis was also performed to compare the outcomes of those who received a dose of ≤15 IU/kg (reduced dose) to those who received >15 IU/kg (standard dose).

METHODS

Patients who received three-factor PCC for warfarin reversal between 1st January and 31st December 2016 were identified and analysed. Clinical data and PCC dosages were extracted from electronic patient records.

RESULTS

Total of 144 patients were analysed. The median INR pre-reversal was 3.25 (range 1.4-10), which reduced to 1.5 (0.9-3.0) post-reversal. 87% of patients achieved a post-reversal INR of less than 2 and 55% less than 1.5. Sixteen patients required a repeat dose. Complications occurred in 22 patients (15.3%), which consisted of 15 deaths, 7 thrombosis and 2 haemorrhage. No statistically significant differences in the primary and secondary outcomes were noted between reduced-dose and standard-dose subgroups.

CONCLUSION

Our results support the use of fixed-dose PCC for warfarin reversal in a day-to-day clinical practice in a hospital setting. This article is protected by copyright. All rights reserved.

Distinguishing aortic valve thrombus from Libman-Sacks endocarditis in antiphospholipid syndrome: imaging and management

Aortic valve (AV) thrombus, a rare complication of antiphospholipid syndrome (APLS), is important to distinguish from Libman-Sacks endocarditis because of its responsiveness to anticoagulation. This may be attributed to immunopathologic differences underpinning their development. We present the case of a 45-year-old woman with high-risk primary APLS who developed an AV mass and was taken for valvular repair surgery but found to have pure thrombus and normal valve leaflets. In such cases, a trial of conservative management with anticoagulation may be adequate. Echocardiography, computed tomography and MRI findings suggestive of thrombus without endocarditis are presented. A literature review of histopathologic, imaging and treatment implications of pure AV thrombus in the context of APLS is included.

Lupus anticoagulant detection in anticoagulated patients. Guidance from the Scientific and Standardization Committee for lupus anticoagulant/antiphospholipid antibodies of the International Society on Thrombosis and Haemostasis

BACKGROUND

The laboratory detection of lupus anticoagulants (LA) in anticoagulated patients represents a challenge and there is no consensus on the types of assays/procedures to be adopted.

OBJECTIVES

This communication of the International Society on Thrombosis and Haemostasis (ISTH), Scientific and Standardization Committee (SSC) aims to give guidance on the procedures to be adopted.

METHODS

Members of the ISTH-SSC on Lupus Anticoagulant/Antiphospholipid Antibodies reviewed the literature to search for evidence on the most appropriate assays/procedures to be adopted.

RESULTS

Anticoagulants are able to interfere with the tests used for LA detection, giving rise to occasional false-positive or false-negative LA. Some commercial tests include in their composition heparin-neutralizers able to quench unfractionated or low molecular weight heparin up to 1.0 U/mL. LA tests are less affected by low molecular weight heparin, but caution is needed in the interpretation of results. Vitamin K antagonists (VKAs) may affect LA detection. Dilution of test plasma into pooled normal plasma is not a reliable solution as false-negative or false-positive LA may occur. Direct oral anticoagulants (DOACs) affect LA detection. Hence, it is not recommended to attempt LA detection in those patients. The use of DOAC adsorbents is a promising solution and should be further investigated on LA-positive and LA-negative patient populations. Taipan/Ecarin tests may be a solution for VKAs and anti-FXa DOACs, but independent evidence on their value and standardized kits is needed.

CONCLUSIONS

LA detection during anticoagulation remains a challenge, especially for VKAs. DOAC removal by in vitro addition to plasma of appropriate absorbents is promising.

Serious Complication of Anticoagulation in Vessel Thrombosis-associated Behçet Disease

Anticoagulation in venous thrombosis associated with Behçet disease (BD) is controversial. We herein report a 47-year-old woman with vessel thrombosis and pulmonary artery aneurysm (PAA) associated with BD who died of massive hemoptysis under oral anticoagulant. Although she was initially diagnosed with oral contraceptive-induced venous thromboembolism, a subsequent investigation led to a diagnosis of BD. Follow-up computed tomography (CT) showed persistent thrombus, so anticoagulant was continued for persistent thrombus. She died of massive hemoptysis after the development of PAA was identified on follow-up CT during the period of anticoagulation. Great care to prevent bleeding events is required when administering anticoagulants for BD with vessel thrombosis.

Successful secondary thromboprophylaxis with direct oral anticoagulants for a patient with catastrophic antiphospholipid syndrome: A case report

RATIONALE

Catastrophic antiphospholipid syndrome (CAPS) is a rare, life-threatening condition of antiphospholipid syndrome (APS). Treatment and management of CAPS remain challenging and the mortality rate is approximately 50% among cases. We describe a successfully treated case of a CAPS patient who had undergone massive bowel resection due to obstruction of superior mesenteric artery.

PATIENT CONCERNS

A 40-year-old male patient was admitted to our hospital with acute abdominal pain, melena, and a history of deep vein thrombosis in both legs for over 10 years, there was no previous diagnosis of APS.

DIAGNOSIS

The patient was diagnosed as CAPS with bowel necrosis due to obstruction of superior mesenteric artery based on the presence of antiphospholipid antibodies, computed tomography scan, and histopathological examination.

INTERVENTIONS

Emergency surgery was performed to remove approximately 6 meters of the necrotic small intestine, of which the length of the remaining small intestine was 40 cm from the duodenum and 80 cm from the ileocaecal valve. Anticoagulants were prescribed with low molecular weight heparin. After discharging, APS was managed with direct oral anticoagulants (DOACs) for secondary thromboprophylaxis because the patient was unable to reach target International Normalized Ratio (INR) with vitamin K antagonists (VKAs).

OUTCOMES

During 24 months of follow-up until now, the patient did not develop new thrombosis or relapse CAPS and his state remained stable.

LESSONS

While VKAs is amongst the most important and fundamental treatment, physicians should be aware that VKAs are absorbed via the small intestine. For CAPS cases who had undergone massive bowel resection, DOACs is a reasonable alternative which has been found to be as safe and effective as VKAs in terms of thrombosis prevention.

Managing thromboembolic risk in patients with hereditary and acquired thrombophilias

While we are now able to diagnose inherited thrombophilias in a substantial number of patients with venous thromboembolism (VTE), the initial hope that their presence would inform recurrence risk and thus decisions on anticoagulation duration has largely been disappointing. Indeed, the presence or absence of transient provoking risk factors has proven to be the most important determinant of VTE recurrence risk. Thus, particular attention to transient acquired risk factors for VTE remains paramount, as they have generally been shown to carry more prognostic weight than inherited thrombophilias. The presence of other acquired risk factors may require additional management considerations, whether pertaining to anticoagulant choice, as in antiphospholipid antibody syndrome, or to addressing a new predisposing medical condition, as in malignancy. Antithrombin deficiency or the presence of ≥1 thrombophilic defect may be exceptions that can have a role in prognostication; however, as illustrated in this review through several case vignettes, interpretation and clinical application of the results of inherited thrombophilia testing is nuanced. We have chosen to focus on cases in which patients have been identified as having thrombophilic defects rather than the indications for undertaking testing in the first place or the extent of investigation. Management decisions in such cases ultimately hinge on individualized consideration of the benefits and risks of anticoagulation along with patient preference rather than on an algorithmic pathway based on thrombophilia status.

Long-term treatment of venous thromboembolism

The most important decision in the long-term treatment of venous thromboembolism (VTE) is how long to anticoagulate. VTE provoked by a reversible risk factor, or a first unprovoked isolated distal deep vein thrombosis (DVT), generally should be treated for 3 months. VTE provoked by a persistent or progressive risk factor (eg, cancer), or a second unprovoked proximal DVT or PE, is generally treated indefinitely. First unprovoked proximal DVT or PE may be treated for 3 to 6 months or indefinitely. Male sex, presentation as PE (particularly if concomitant proximal DVT), a positive d-dimer test after stopping anticoagulation, an antiphospholipid antibody, low risk of bleeding, and patient preference favor indefinite anticoagulation. The type of indefinite anticoagulation is of secondary importance. Low-dose oral Xa inhibitors are convenient and are thought to have a lower risk of bleeding; they are less suitable if there is a higher risk for recurrence. For cancer-associated VTE, we now prefer full-dose oral Xa inhibitors over low-molecular-weight heparin, with gastrointestinal lesions being a relative contraindication. Graduated compression stockings are not routinely indicated after DVT, but are encouraged if there is persistent leg swelling or if a trial of stockings improves symptoms. Medications have a limited role in the treatment of postthrombotic syndrome. After PE, patients should have clinical surveillance for chronic thromboembolic pulmonary hypertension (CTEPH), with ventilation-perfusion scanning and echocardiography being the initial diagnostic tests if CTEPH is a concern. Patients with CTEPH and other symptomatic patients with extensive residual perfusion defects should be evaluated for endarterectomy, balloon pulmonary angioplasty, or vasodilator therapies.

Antiphospholipid syndrome and the relationship between laboratory assay positivity and prevalence of non-bacterial thrombotic endocarditis: A retrospective cohort study

BACKGROUND

Nonbacterial thrombotic endocarditis (NBTE) is a potential complication of antiphospholipid syndrome (APS) manifesting as noninfectious lesions on one or more cardiac valves. There are limited tools to inform clinicians regarding which APS patients would benefit most from echocardiographic screening for this complication.

OBJECTIVES

We tested the hypothesis that the risk of both prevalent and incident NBTE is directly related to the number of positive laboratory assays for APS.

PATIENTS/METHODS

In this single-center, retrospective, cohort study design, consecutive patients with confirmed APS seen at Mayo Clinic Rochester, MN (1/1/1993-6/26/2016), were identified by searching a centralized electronic database. Demographic data, clinical presentation, echocardiographic features, laboratory findings, and survival data were scrutinized.

RESULTS

During the study period, 611 patients met the diagnostic criteria for APS and 386 (63%) underwent echocardiography. Of these, 58 (15%) were found to have NBTE. NBTE was more common in those with double (19.4%) and triple-positive laboratory criteria (27.0%) compared with single-positive disease (5.7%, P < .001). Survival free of NBTE diagnosis was significantly shorter in those patients with >1 positive laboratory assay (P < .01). Cox proportional hazard analysis suggests that patients with APS are more likely to be diagnosed with NBTE if they have >1 positive laboratory assay (relative risk 20.1; 95% confidence interval 1.3-316.6; P < .03).

CONCLUSION

Antiphospholipid syndrome carries a high prevalence of NBTE (15%). This prevalence is particularly high for patients with either double- or triple-positive laboratory criteria.

Antiphospholipid Syndrome Committee of the Brazilian Society of Rheumatology position statement on the use of direct oral anticoagulants (DOACs) in antiphospholipid syndrome (APS)

BACKGROUND

The term Direct Oral Anticoagulants (DOACs) refers to a group of drugs that inhibit factor Xa or thrombin. Even though their use for treating different thrombotic or prothrombotic conditions is increasing recently, there is no compelling evidence indicating that those medications are safe in all antiphospholipid syndrome (APS) patients.

METHODOLOGY

To address this issue, specialists from the Antiphospholipid Syndrome Committee of the Brazilian Society of Rheumatology performed a comprehensive review of the literature regarding DOACs use in APS to answer the three following questions: (1) potential mechanisms of action of these drugs that could be relevant to APS pathogenesis, (2) DOACs interference on lupus anticoagulant testing, and (3) the efficacy of DOACs in APS.

POSITION STATEMENT

After critically reviewing the relevant evidence, the authors formulated 8 Position Statements about DOACs use in APS.

CONCLUSION

DOACs should not be routinely used in APS patients, especially in those with a high-risk profile (triple positivity to aPL, arterial thrombosis, and recurrent thrombotic events). In addition, DOACs interferes with LA testing, leading to false-positive results in patients investigating APS.

Thrombin Generation in a patient with Triple Positive Antiphospholipid Syndrome Treated with Three Different Anticoagulants

INTRODUCTION

Venous and arterial thrombosis is one of the hallmarks of Antiphospholipid Antibody Syndrome (APS). The traditional treatment for individuals with APS and venous thrombosis has been vitamin K antagonists. However, with the widespread use of direct oral anticoagulants (DOACs) there has been conflicting evidence regarding their safety and failure rate as alternatives to warfarin. Reasons for this failure remain elusive. We utilized the thrombin generation assay (TGA) to investigate the anticoagulation efficacy of three different agents in a patient with triple-positive APS to acquire a better understanding of the pathophysiology of APS.

METHODS

Blood samples were obtained from a single patient with APS at five distinct time points while on three different anticoagulants: rivaroxaban, warfarin, and enoxaparin. The effects of these anticoagulants on TG potential were evaluated using the TGA.

RESULTS

In the presence of thrombomodulin, rivaroxaban had the highest endogenous thrombin potential, thrombin peak, velocity index, and thrombin inactivation velocity (821.9 nMmin, 121.5 nM, 36.44 nM/min, 7.19 nM/min) when compared to warfarin (121-367 nMmin, 13.85-121.5 nM, 3.02-3.85 nM/min, 0.64-4.55 nM/min) and enoxaparin (242-378.8 nM min, 21.33-23.78 nM, 2.87-3.85 nM/min, 0.747-0.784 nM/min). This trend was also observed in the absence of thrombomodulin.

CONCLUSIONS

These results suggest that patients with APS treated with rivaroxaban may be at greater risk for thrombosis compared to warfarin or enoxaparin. The findings may provide insight into the recent studies in patients with triple positive APS randomized to different anticoagulants demonstrating high rates of thrombosis with rivaroxaban. Further studies are necessary to elucidate the clinical significance.

The importance of antiphospholipid syndrome testing in venous thromboembolism after varicose vein surgery

Anticoagulation treatment after a venous thromboembolism event is usually managed on a case-by-case basis. The risk of thrombosis must be weighed against the risk of bleeding. Identifying patients who could benefit from anticoagulation therapy requires the thromboembolism event to be assessed with respect to its presentation and the severity of the triggering factors. A case report is employed to explain the important aspects of practical approaches to venous thromboembolism events after vein surgery. The Trial on Rivaroxaban in AntiPhospholipid Syndrome (TRAPS) study has prompted new considerations for anticoagulation management. Patients with antiphospholipid syndrome need to be identified early to lower the risk of thromboembolism also during anticoagulation treatment.

Antiphospholipid syndrome and challenges with direct oral anticoagulants

Direct oral anticoagulants have become the mainstay of the management of venous thromboembolism and atrial fibrillation, and long-term anticoagulation is indicated for those at high risk of further thrombotic events. This includes patients diagnosed with antiphospholipid syndrome, for whom the 'triple positive' laboratory combination of lupus anticoagulant, β2-glycoprotein-1 and anti-cardiolipin antibodies signify those at greatest risk. Data from meta-analysis and randomised control trials have raised the concern that direct oral anticoagulants may be less effective than vitamin K antagonists for the prevention of thrombosis in patients with thrombotic antiphospholipid syndrome, particularly those with the triple positive profile. This article reviews the diagnosis of thrombotic antiphospholipid syndrome, strategies for testing without interruption of anticoagulation, evidence concerning the safety of direct oral anticoagulants in this setting, and the implications for current investigation and management of unprovoked venous thromboembolism.

An update on the management of antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by recurrent venous or arterial thrombosis with or without pregnancy morbidity in the presence of persistent antiphospholipid (aPL) autoantibodies. Anticoagulation has, until now, formed the cornerstone of treatment but a significant proportion of patients continue to experience thrombosis and pregnancy morbidity despite this treatment. Thrombosis is the most common cause of mortality and accounts for two fifths of deaths. Direct oral anticoagulant drugs represent an attractive alternative to conventional vitamin K antagonist drugs but emerging evidence suggests these may not be suitable for high-risk patients with thrombotic APS. Laboratory studies and case reports of the successful use of different classes of drugs in APS is increasing our understanding of the other pathophysiological mechanisms which may contribute to the high morbidity of APS. This review summarizes current accepted anticoagulant treatment for APS and examines other potential drugs such as immunomodulating agents, statins and novel agents such as sirolimus and defibrotide.

A single-arm feasibility cohort study of rivaroxaban in antiphospholipid syndrome

Background

There is uncertainty regarding the safety and effectiveness of direct oral anticoagulant agents in patients with antiphospholipid syndrome (APS). We performed a multicenter feasibility study to examine our ability to identify and obtain consent from eligible APS patients and to obtain 95% adherence with daily rivaroxaban administration, in order to inform and power a larger study. Clinical outcomes of bleeding and thrombosis were also collected.

Methods

APS patients with prior venous thromboembolism (VTE) were recruited over 2 years (Oct 2014-Sept 2016) and followed for ≥ 1 year. Patients were assessed clinically every 3 months and had pill counts performed every 6 months. Numbers of patients fulfilling study criteria, as well as those consenting to participate, were tracked, and percentage adherence based on pill counts was recorded. These data were compared against the feasibility endpoints. Rates of thrombosis and bleeding were calculated. Criterion for feasibility was obtaining consent from 135 of 150 identified APS patients over 2 years.

Results

Ninety-six eligible patients were identified, and 14 declined participation. Eighty-two patients were followed for a mean of 19 months, representing 129.8 patient-years. Average rivaroxaban adherence was 95.0%. During follow-up, there were 4 thromboembolic events (2 cerebrovascular and 2 VTE). There were no episodes of major bleeding.

Conclusions

Adequately powered comparative trials using patient-important outcomes in APS are unlikely to be successful due to inability to recruit sufficient numbers of study subjects. This study does not reveal a higher than expected risk of recurrent thromboembolic disease compared to historical cohorts; however, this is an uncontrolled study in relatively low-risk APS patients.

Trial registration

The study was registered with clinicaltrials.gov, identifier NCT02116036, April 16, 2014.

Thrombophilia evaluation in pulmonary embolism

PURPOSE OF REVIEW

Patients with pulmonary embolism commonly undergo thrombophilia evaluation for a variety of reasons including risk stratification for recurrent venous thromboembolism (VTE) and treatment planning. However, the utility of thrombophilia testing in many clinical scenarios remains unclear. This review evaluates current recommendations for thrombophilia testing described in consensus VTE guidelines, recent literature on the clinical application of these recommendations, novel genetic assessments for hereditary thrombophilias, and studies evaluating use of direct oral anticoagulants (DOACs) in VTE patients with thrombophilias.

RECENT FINDINGS

Current VTE guidelines advise limited use of thrombophilia testing, recognizing that testing may be misinterpreted and frequently does not lead to a change in management. Testing and test results are not necessarily benign, are frequently misinterpreted, and can lead to increased anxiety in both patients and clinicians. Recent studies have offered innovative techniques to better align clinical practice with these recommendations as well as expanded genomic assessments to improve the scope and predictive value of thrombophilia testing. There is also emerging literature on the appropriateness of direct oral anticoagulant therapy for VTE patients with hereditary thrombophilias or antiphospholipid syndrome.

SUMMARY

Thrombophilia testing in its current form does not significantly impact clinical management or improve outcomes for most VTE patients. Therefore, it should be employed judiciously and only in patients for whom it is likely to alter clinical management. Novel expanded genomic thrombophilia testing approaches and additional studies evaluating optimal anticoagulant treatment in various thrombophilia subpopulations will make thrombophilia testing more useful for patients moving forward.

Prevalence of confirmed antiphospholipid syndrome in 18-50 years unselected patients with first unprovoked venous thromboembolism

BACKGROUND

Antiphospholipid syndrome (APS) is an acquired thrombophilia disorder with prevalence not completely known in patients with first unprovoked venous thromboembolic events (VTE). Recent data suggest that the management of some APS patients should be different from that of patients with other thrombophilia. Our aim was to estimate the prevalence of APS in a community-based cohort of patients with a first unprovoked VTE.

METHODS

We conducted a cross-sectional study analyzing data from our computer assisted oral anticoagulant dosage program. Data of all consecutive patients aged 18 to 50 years who were seen between January 1, 2002 and December 31, 2011 for a first proximal unprovoked VTE were extracted. The prevalence and main features of patients who fulfilled the Sapporo revised criteria for APS were collected.

RESULTS AND DISCUSSION

A total of 524 incident patients aged 18 to 50 years were included in the anticoagulation clinic during the study period. Of them, 491 were tested for APS and 44 (9.0%; 95% confidence interval [CI]: 6.7-11.8) fulfilled APS criteria. Of 26 APS women, 8 (30.8%) were on combined oral contraceptive pill at the time of VTE, versus 108 (55.1%) in non-APS women (P = .02). No difference was observed between APS and non-APS patients in terms of gender or type of VTE. The prevalence of APS is high in young patients with a first unprovoked VTE. In the direct oral anticoagulant era, when and how to test for APS is challenging and deserves further investigation.