Factor Xa inhibitors vs. warfarin in patients with Hughes syndrome: a systematic review and meta-analysis of randomized controlled trials

Background

The optimal treatment regimen for patients with Hughes syndrome remains unclear. Therefore, the authors sought to compare the outcomes of warfarin vs. factor Xa inhibitors in patients with Hughes syndrome.

Methods

MEDLINE, Embase, and Cochrane Central databases were searched for randomized controlled trials (RCTs) comparing 8 efficacy and safety of warfarin and factor Xa inhibitors in patients with Hughes syndrome. Recurrent thrombosis, all-cause mortality, stroke, adverse reactions, and bleeding were among 10 outcomes of interest. Mantel-Haenszel weighted random-effects model was used to calculate 11 relative risks (RRs) with 95% CIs.

Results

The analysis included 625 patients from four RCTs and one post-hoc analysis. Meta-analysis showed a statistically non-significant difference between factor Xa inhibitors and warfarin in the recurrent thrombosis risk (arterial or venous) [RR 2.77 (95%, CI 0.79, 9.65); P=0.11, I2=50%]. Consistent results were revealed among patients with a previous history of arterial thrombosis [RR 2.76 (95% CI 0.93, 8.16); P=0.75, I2=0%], venous thrombosis [RR 1.71 (95% CI 0.60, 4.84); P=0.31, I2=15%] and patients who were triple antiphospholipid antibodies (aPL) positive [RR 4.12 (95% CI 0.46, 37.10); 21 P=0.21, I2=58%]. Factor Xa inhibitors were significantly associated with an increased risk of stroke [RR 8.51 (95% CI 2.35, 13.82); P=0.47, I2=0%].

Conclusion

Factor Xa inhibitors exhibited an increased risk of stroke among patients with Hughes syndrome. In addition, although not significant, the higher RRs among patients on factor Xa inhibitors may indicate a higher risk of thrombotic events associated with factor Xa inhibitors.

Bilateral pulmonary embolism associated with peripheral blood eosinophilia and positive antiphospholipid antibodies in a patient with cellulitis

Key Clinical Message

This report described the pathophysiology, diagnostic workup, and management of thrombosis possibly associated with peripheral blood eosinophilia and transient positive antiphospholipid antibodies in the setting of cellulitis.

Abstract

Peripheral blood eosinophilia is a risk factor for thrombosis and the presence of other prothrombotic factors such as antiphospholipid antibodies can potentiate that risk. The authors present a case of acute pulmonary embolism which developed at the peak of eosinophilia, later found to have transient positive antiphospholipid antibodies in a male patient with right lower limb cellulitis and a history of intravenous drug abuse. This report illustrates the pathophysiology, diagnosis workup, and therapeutic options of thrombosis possibly associated with peripheral blood eosinophilia and positive antiphospholipid antibodies, which include anticoagulants, corticosteroids, and immunosuppressants. Clinicians should be aware of this possible association which may guide the choice and duration of anticoagulants. Although direct oral anticoagulants are effective anticoagulants in various thromboembolic events, studies showed unfavorable outcomes for their use in antiphospholipid syndrome.

Direct-acting oral anticoagulants in antiphospholipid syndrome: A systematic review

The objective of the systematic review is to analyze the efficacy of direct-acting oral anticoagulants (DOAC) in the prophylaxis of thrombosis in antiphospholipid syndrome (APS). We searched for clinical trials, cohort studies and meta-analyses published from January 1, 2012 to September 30, 2022. Articles that analyzed the efficacy of DOAC in the prevention of thrombosis recurrence, with or without comparison with antivitamin K (VKA) drugs, were selected. DOACs, specifically rivaroxaban and apixaban, were significantly less effective than VKAs in preventing recurrence of thrombosis in patients with APS and prior arterial thrombosis or the concomitant presence of two or three different antiphospholipid antibodies. The proportion of patients with severe bleeding as side effect are similar in those treated with DOAC and with VKA. The results argue against the use of DOAC in the treatment of patients with thrombotic APS.

Cerebral venous thrombosis in patients with Sjögren's syndrome: A case report and literature review

Although cerebral venous thrombosis (CVT) is known to be induced by autoimmune diseases such as systemic lupus erythematosus and antiphospholipid syndrome, CVT caused by Sjögren's syndrome (SS) is scarcely reported in the medical literature. Since the first report of SS-induced CVT in 1994, only five cases have been reported, and the clinicopathological features of the disease are not well documented. We herein present a case report of a 41-year-old woman who was diagnosed with SS-induced CVT and perform a literature review of six cases of SS-induced CVT with a discussion of the pathogenesis, features of clinic symptoms, treatment, and prognosis of SS-associated CVT. We aim to improve the understanding of SS-induced CVT among clinicians and reduce the incidence of missed clinical diagnoses.

Factor XI/XIa Inhibition: The Arsenal in Development for a New Therapeutic Target in Cardio- and Cerebrovascular Disease

Despite major advancements in the development of safer and more effective anticoagulant agents, bleeding complications remain a significant concern in the treatment of thromboembolic diseases. Improvements in our understanding of the coagulation pathways highlights the notion that the contact pathway-specifically factor XI (FXI)-has a greater role in the etiopathogenesis of thrombosis than in physiological hemostasis. As a result, a number of drugs targeting FXI are currently in different stages of testing and development. This article aims to review the different strategies directed towards FXI-inhibition with a brief summation of the agents in clinical development, and to comment on the therapeutic areas that could be explored for potential indications. Therapeutics targeting FXI/FXIa inhibition have the potential to usher in a new era of anticoagulation therapy.

Neurologic Manifestations of Catastrophic Antiphospholipid Syndrome

PURPOSE OF REVIEW

Understanding of antiphospholipid antibody syndrome (APS), associated neurological manifestations, and disease-directed treatment has grown considerably over the last decade. Herein, we critically review the current and high-yield literature related to the pathophysiology, neurological presentations, and management of APS with particular emphasis on the rare and more fatal subset of APS, catastrophic antiphospholipid syndrome (CAPS).

RECENT FINDINGS

APS may manifest with a variety of neurologic syndromes, with cerebrovascular disease representing the most commonly encountered presentation. Diagnostic evaluation and treatment are often tailored to the specific presentation, with suspicion and testing for antiphospholipid antibodies recommended when neurologic presentations occur atypically or in younger individuals. In CAPS, which is more rapidly progressive with multiorgan involvement, potential alternative microangiopathic syndromes should be carefully considered in the differential diagnosis. To date, anticoagulation with vitamin K antagonists remains the mainstay of therapy in APS while triple therapy with anticoagulation, corticosteroids, and plasma exchange is standard of care in CAPS. Immunotherapy has shown early promise in refractory cases. APS is an autoimmune clinical syndrome with neurologic presentations classically characterized by vascular thrombosis, though recent understandings suggest additional direct immune-mediated phenomena. Our understanding of the underlying pathogenic mechanisms of APS continues to grow and will continue to influence our therapeutic approaches.

Neuropsychiatric Systemic Lupus Erythematosus: a remaining challenge

Systemic Lupus Erythematosus (SLE) is an autoimmune disease, which affects a wide range of organs with variable clinical features. Involvement of the nervous system is a challenging and multifaceted manifestation of the disease, presenting with a broad range of symptoms. Neuropsychiatric lupus (NPSLE) encompasses seven syndromes of the peripheral and 12 of the central nervous system, associated with a high disease burden. Despite advances in the management of SLE, NP manifestations still pose a challenge to clinicians. First, diagnosis and attribution to SLE is difficult due to the lack of specific biomarkers or imaging modalities. Second, therapeutic options are limited, and evidence is mainly based on case reports and expert consensus, as clinical trials are sparse. Moreover, no validated outcome measure on disease activity exists. Current recommendations for treatment include supportive as well as immunosuppressive medication, depending on the type and severity of manifestations. As NPSLE manifestations are increasingly recognized, a broader spectrum of therapeutic options can be expected.

Recurrent strokes and memory loss in a patient with triple-positive antiphospholipid antibody syndrome

Antiphospholipid syndrome may cause recurrent thromboembolic events of the microvasculature, arteries and veins. It is also characterised by a range of neurological and psychiatric dysfunctions, as well as complications during pregnancy. Patients with triple-positive antiphospholipid syndrome have persistently elevated levels of lupus anticoagulant (LA), anti-beta-2-glycoprotein I (B2GPI) and anticardiolipin antibodies (aCL). These patients also have a higher risk of initial or recurrent thrombosis.We report the case of a 36-year-old man who was presented with progressive memory loss and recurrent stroke. He had persistently elevated antiphospholipid antibody titres (LA, aCL-immunoglobulin G and B2GPI antibodies). These features persisted while the patient was receiving low-dose aspirin (LDA), 81mg daily. Vitamin K antagonist (VKA); warfarin, with the international normalised ratio (INR) maintained at 2-3 was then added to his treatment regimen. The VKA dose was maintained at - a higher therapeutic INR while LDA administration was continued to achieve resolution of the patient's symptoms.

Evaluation of Apixaban in Patients With Antiphospholipid Syndrome: A Case Series and Review of Literature

Several guidelines endorsed the indefinite use warfarin or heparin-containing products for acute venous thromboembolism (VTE) treatment and secondary prevention and discouraged the use of direct oral anticoagulants (DOAC) for patients diagnosed with antiphospholipid syndrome (APS). However, adequate anticoagulation despite warfarin therapy remains a challenge in APS patients. Using DOACs in APS patients is seen in clinical practice, despite the lack of evidence to support their use in this population. In this case series, we aim to evaluate the safety and effectiveness of apixaban use in nine patients with primary or secondary APS at King Abdulaziz Medical City (Riyadh, Saudi Arabia). All patients presented with APS and received apixaban with or without concomitant antiplatelet. Three patients had double positivity, and two patients had triple positivity of antiphospholipid antibodies (aPL). Some patients tolerated apixaban during the follow-up period, but recurrent VTE and stroke were reported in some of them. Bleeding complications were evident in some cases as well. In conclusion, warfarin remains the best choice to prevent VTE recurrence in patients with APS. On the other side, apixaban use in patients with APS may have some safety and effectiveness concerns evidenced by VTE recurrence and bleeding complications. The safety and effectiveness of utilizing apixaban in APS patients need to be assessed in well-controlled randomized trials.

Direct oral anticoagulants versus warfarin in patients with single or double antibody-positive antiphospholipid syndrome

Warfarin is recognized as the standard treatment for thrombotic antiphospholipid syndrome (APS); however, direct oral anticoagulants (DOACs) represent appealing therapeutic alternatives given their lack of monitoring and limited drug interactions. A few randomized controlled trials comparing rivaroxaban with warfarin showed an increased risk of recurrent thromboembolism, specifically arterial thrombosis, in patients with high risk forms of APS such as those that are triple antibody positive. We conducted a single-center, retrospective cohort study of all patients within our health system from 2015 to 2020 with a diagnosis of APS (single or double antibody positive) and history of venous thromboembolism. We sought to compare the proportion of patients with a recurrent thrombosis when prescribed a DOAC versus warfarin. Among 96 patients included, 57 were prescribed warfarin and 39 were prescribed a DOAC (90% rivaroxaban). The proportion of patients with a recurrent thromboembolism was almost three times higher in the DOAC group (15.4%) compared to the warfarin group (5.3%), although this was not statistically significant (p = 0.15). Major bleeding was not different between groups. Our findings suggest that rivaroxaban may pose an increased risk for recurrent thromboembolism in low risk APS patients that are single or double-antibody positive compared to warfarin. Results of our study should be cautiously applied to DOACs besides rivaroxaban given their small representation in this study.

Apixaban compared with warfarin to prevent thrombosis in thrombotic antiphospholipid syndrome: a randomized trial

The primary outcome, stroke, occurred in 6 of 23 patients randomized to apixaban compared with 0 of 25 patients randomized to warfarin.

This study with limitations suggests that apixaban is not an equitable substitute for warfarin to prevent thrombosis among TAPS patients.

Thrombotic antiphospholipid syndrome (TAPS) is characterized by venous, arterial, or microvascular thrombosis. Patients with TAPS merit indefinite anticoagulation, and warfarin has historically been the standard treatment. Apixaban is an oral factor Xa inhibitor anticoagulant that requires no dose adjustment or monitoring. The efficacy and safety of apixaban compared with warfarin for TAPS patients remain unknown. This multicenter prospective randomized open-label blinded endpoint study assigned anticoagulated TAPS patients to apixaban or warfarin (target international normalized ratio 2-3) for 12 months. The primary efficacy outcome was clinically overt thrombosis and vascular death. Apixaban was first given at 2.5 mg twice daily. Two protocol changes were instituted based on recommendations from the data safety monitoring board. After the twenty-fifth patient was randomized, the apixaban dose was increased to 5 mg twice daily, and after the thirtieth patient was randomized, subjects with prior arterial thrombosis were excluded. Primary outcomes were adjudicated by independent experts blinded to treatment allocation. Patients randomized between 23 February 2015 and 7 March 2019 to apixaban (n = 23) or warfarin (n = 25) were similar. Among the components of the primary efficacy outcome, only stroke occurred in 6 of 23 patients randomized to apixaban compared with 0 of 25 patients randomized to warfarin. The study ended prematurely after the forty-eighth patient was enrolled. Conclusions from our study are limited due to protocol modifications and low patient accrual. Despite these limitations, our results suggest that apixaban may not be routinely substituted for warfarin to prevent recurrent thrombosis (especially strokes) among patients with TAPS. This trial was registered at www.clinicaltrials.gov as #NCT02295475.

Use of Direct Oral Anticoagulants in Patients With Antiphospholipid Syndrome: A Systematic Review and Comparison of the International Guidelines

Antiphospholipid antibody syndrome (APS) requires long-term anticoagulation to prevent recurrent thrombosis. Direct oral anticoagulants (DOACs) have been increasingly used in APS patients, but contradictory guidelines recommendations on their use do exist. We performed a systematic review of literature including studies investigating the role of DOACs in APS patients. At this aim, PubMed and Cochrane databases were searched according to PRISMA guidelines. We identified 14 studies which investigated the use of DOACs in patients with APS, of which 3 randomized clinical trials (RCTs), 1 post-hoc analysis of 3 RCTs, 7 case series and 3 cohort studies (2 prospective and 1 retrospective). Among DOACs, rivaroxaban was the most used (n = 531), followed by dabigatran (n = 90) and apixaban (n = 46). Regarding guidelines indications, the 2019 European Society of Cardiology (ESC) and American Society of Hematology (ASH) guidelines recommend against the use of DOACs in all APS patients. The European League Against Rheumatism (EULAR), British Society for Haematology (BSH), and International Society on Thrombosis and Haemostasis (ISTH) guidance provided more detailed indications stating that warfarin should be the first-choice treatment but DOACs may be considered in patients (1) already on a stable anticoagulation with a DOAC, (2) with low-quality anticoagulation by warfarin, (3) unwilling/unable to undergo INR monitoring, (4) with contraindications or serious adverse events under warfarin. Patients with arterial APS or triple positivity should be treated with warfarin while venous APS with single or double positivity may be candidate to DOACs, but high-quality studies are needed.

Neurologic Manifestations of the Antiphospholipid Syndrome - an Update

PURPOSE OF REVIEW

In recent years, the spectrum of neurological manifestations of antiphospholipid syndrome (APS) has been growing. We provide a critical review of the literature with special emphasis on presentation, proposed mechanisms of disease, and treatment of neurological involvement in APS.

RECENT FINDINGS

Although stroke is the most common cause of neurological manifestations in patients with APS, other neurological disorders have been increasingly associated with the disease, including cognitive dysfunction, headache, and epilepsy. Direct oral anticoagulants have failed to show non-inferiority compared to vitamin K antagonists for the prevention of major thrombotic events. Antiphospholipid antibodies are often found in patients with acute COVID-19 but clear evidence supporting an association between these antibodies and the risk of thrombotic events, including stroke and cerebral venous thrombosis, is still lacking. APS patients may present with several distinct neurological manifestations. New criteria will facilitate the classification of patients presenting with increasingly recognized non-criteria neurological manifestations.

Massive thrombosis and phlegmasia cerulea dolens while taking rivaroxaban: case report and review

Our study describes a fatal case of phlegmasia cerulea dolens and massive venous thrombosis in a patient taking rivaroxaban regularly to treat cerebral venous sinus thrombosis. Blood tests samples were positive for lupus anticoagulant. The unique evolution of the case, as well as the positivity for lupus anticoagulant, raises the possibility of an acquired hypercoagulation syndrome. We highlight the fact that the test recommended as the first line for lupus anticoagulant diagnosis (dilute Russell viper venom time) is the most affected by rivaroxaban, leading to a high prevalence of false-positive results. We also discuss potential diagnoses for the current case and review the current state-of-the-art of use of the novel oral anticoagulation agents in this unusual situation. So far, there are no recommendations to use such agents as first options in cerebral venous sinus thrombosis or in hypercoagulation syndromes.

Antiphospholipid syndrome

Antiphospholipid syndrome is one of the more common acquired causes of hypercoagulability. Its major presentations are thrombotic (arterial, venous, or microvascular) and pregnancy morbidity (miscarriages, late intrauterine fetal demise, and severe pre-eclampsia). Classification criteria include 3 different antiphospholipid antibodies: lupus anticoagulant, anticardiolipin, and anti-beta 2 glycoprotein I. Management includes both preventive strategies (low-dose aspirin, hydroxychloroquine) and long-term anticoagulation after thrombosis.

Direct Oral Anticoagulants in Select Patients With Hypercoagulable Disorders

OBJECTIVE

To summarize the literature assessing the safety and efficacy of direct oral anticoagulants (DOACs) for the acute treatment and secondary prevention of venous thromboembolism (VTE) in select patients with hypercoagulable disorders.

DATA SOURCES

An electronic PubMed literature search was conducted from January 2010 to July 2020 using the following keywords: DOAC, rivaroxaban, apixaban, dabigatran, edoxaban, thrombophilia, cancer, antiphospholipid syndrome, protein C deficiency, protein S deficiency, antithrombin deficiency, factor V Leiden, prothrombin G20210A gene mutation, congenital thrombophilia, hypercoagulable, hereditary thrombophilia, acquired thrombophilia.

STUDY SELECTION AND DATA EXTRACTION

Articles were included if they reported clinical outcomes associated with cancer-associated VTE, antiphospholipid syndrome (APS), and other hereditary thrombophilias.

DATA SYNTHESIS

The safety and efficacy of using a DOAC is highly dependent on the type of hypercoagulable disease state. Current trials support the use of edoxaban, rivaroxaban, and apixaban for the treatment of cancer-associated thrombosis (CAT), with apixaban being preferred because of lower bleeding rates compared with standard of care. The use of DOACs, especially rivaroxaban, have been associated with worse outcomes in patients with APS, whereas data on DOAC use in hereditary thrombophilia remains scarce and limited to low-risk patients.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review evaluates the literature assessing the safety and efficacy of DOACs in patients with various hypercoagulable disorders.

CONCLUSIONS

The current body of evidence supports the use of select DOACs for the treatment of CAT. In contrast, DOAC use in patients with APS and hereditary thrombophilia should be avoided at this time.

Antiplatelet and anticoagulant agents for secondary prevention of stroke and other thromboembolic events in people with antiphospholipid syndrome

BACKGROUND

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by arterial or venous thrombosis (or both), and/or pregnancy morbidity in association with the presence of antiphospholipid antibodies. The prevalence of APS is estimated at 40 to 50 cases per 100,000 people. The most common sites of thrombosis are cerebral arteries and deep veins of the lower limbs. People with a definite APS diagnosis have an increased lifetime risk of recurrent thrombotic events.

OBJECTIVES

To assess the effects of antiplatelet (AP) or anticoagulant agents, or both, for the secondary prevention of recurrent thrombosis, particularly ischemic stroke, in people with APS.

SEARCH METHODS

We last searched the MEDLINE, Embase, CENTRAL, Cochrane Stroke Group Trials Register, and ongoing trials registers on 22 November 2019. We checked reference lists of included studies, systematic reviews, and practice guidelines. We also contacted experts in the field.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated any anticoagulant or AP agent, or both, in the secondary prevention of thrombosis in people with APS, according to the criteria valid when the study took place. We did not include studies specifically addressing women with obstetrical APS.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently worked on each step of the review, following Cochrane methods. We summarized the evidence using the GRADE approach.

MAIN RESULTS

We identified eight studies including 811 participants that compared different AP or anticoagulant agents. NOAC (non-VKA oral anticoagulant: rivaroxaban 15 or 20 mg/d) versus standard-dose VKA (vitamin K antagonist: warfarin at moderate International Normalized Ratio [INR] - 2.5) or adjusted [INR 2.0-3.0] dose): In three studies there were no differences in any thromboembolic event (including death) and major bleeding (moderate-certainty evidence), but an increased risk of stroke (risk ratio [RR] 14.13, 95% confidence interval [CI] 1.87 to 106.8; moderate-certainty evidence). One of the studies reported a small benefit of rivaroxaban in terms of quality of life at 180 days measured as health state on Visual Analogue Scale (mean difference [MD] 7 mm, 95% CI 2.01 to 11.99; low-certainty evidence), but not measured as health utility on a scale from 0 to 1 (MD 0.04, 95% CI -0.02 to 0.10; low-certainty evidence). High-dose VKA (warfarin with a target INR of 3.1 to 4.0 [mean 3.3] or 3.5 [mean 3.2]) versus standard-dose VKA (warfarin with a target INR of 2.0 to 3.0 [mean 2.3] or 2.5 [mean 2.5]): In two studies there were no differences in the rates of thrombotic events and major bleeding (RR 2.22, 95% CI 0.79 to 6.23, low-certainty evidence), but an increased risk of minor bleeding in one study during a mean of 3.4 years (standard deviation [SD] 1.2) of follow-up (RR 2.55, 95% CI 1.07 to 6.07). In both trials there was evidence of a higher risk of any bleeding (hazard ratio [HR] 2.03 95% CI 1.12 to 3.68; low-certainty evidence) in the high-dose VKA group, and for this outcome (any bleeding) the incidence is not different, only the time to event is showing an effect. Standard-dose VKA plus a single AP agent (warfarin at a target INR of 2.0 to 3.0 plus aspirin 100 mg/d) versus standard-dose VKA (warfarin at a target INR of 2.0 to 3.0): One high-risk-of-bias study showed an increased risk of any thromboembolic event with combined treatment (RR 2.14, 95% CI 1.04 to 4.43; low-certainty evidence) and reported on major bleeding with five cases in the combined treatment group and one case in the standard-dose VKA treatment group, resulting in RR 7.42 (95% CI 0.91 to 60.7; low-certainty evidence) and no differences for secondary outcomes (very low- to low-certainty evidence). Single/dual AP agent and standard-dose VKA (pooled results): Two high-risk-of-bias studies compared a combination of AP and VKA (aspirin 100 mg/d plus warfarin or unspecified VKA at a target INR of 2.0 to 3.0 or 2.0 to 2.5) with a single AP agent (aspirin 100 mg/d), but did not provide any conclusive evidence regarding the effects of those drugs in people with APS (very low-certainty evidence). One of the above-mentioned studies was a three-armed study that compared a combination of AP and VKA (aspirin 100 mg/d plus warfarin at a target INR of 2.0 to 2.5) with dual AP therapy (aspirin 100 mg/d plus cilostazol 200 mg/d) and dual AP therapy (aspirin 100 mg/d plus cilostazol 200 mg/d) versus a single AP treatment (aspirin 100 mg/d). This study reported on stroke (very low-certainty evidence) but did not report on any thromboembolic events, major bleeding, or any secondary outcomes. We identified two ongoing studies and three studies are awaiting classification.

AUTHORS' CONCLUSIONS

The evidence identified indicates that NOACs compared with standard-dose VKAs may increase the risk of stroke and do not appear to alter the risk of other outcomes (moderate-certainty evidence). Using high-dose VKA versus standard-dose VKA did not alter the risk of any thromboembolic event or major bleeding but may increase the risk of any form of bleeding (low-certainty evidence). Standard-dose VKA combined with an AP agent compared with standard-dose VKA alone may increase the risk of any thromboembolic event and does not appear to alter the risk of major bleeding or other outcomes (low-certainty evidence). The evidence is very uncertain about the benefit or harm of using standard-dose VKA plus AP agents versus single or dual AP therapy, or dual versus single AP therapy, for the secondary prevention of recurrent thrombosis in people with APS (very low-certainty evidence).

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.

Cardiovascular Disease in Antiphospholipid Syndrome

:

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.

:

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.

:

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.

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.

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.

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.

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.

Recommendations of the Spanish Rheumatology Society for Primary Antiphospholipid Syndrome. Part I: Diagnosis, Evaluation and Treatment

OBJECTIVE

The difficulty in diagnosis and the spectrum of clinical manifestations that can determine the choice of treatment for primary antiphospholipid syndrome (APS) has fostered the development of recommendations by the Spanish Society of Rheumatology (SER), based on the best possible evidence. These recommendations can serve as a reference for rheumatologists and other specialists involved in the management of APS.

METHODS

A panel of four rheumatologists, a gynaecologist and a haematologist with expertise in APS was created, previously selected by the SER through an open call or based on professional merits. The stages of the work were: identification of the key areas for drafting the document, analysis and synthesis of the scientific evidence (using the Scottish Intercollegiate Guidelines Network [SIGN] levels of evidence) and formulation of recommendations based on this evidence and formal assessment or reasoned judgement techniques (consensus techniques).

RESULTS

46 recommendations were drawn up, addressing five main areas: diagnosis and evaluation, measurement of primary thromboprophylaxis, treatment for APS or secondary thromboprophylaxis, treatment for obstetric APS and special situations. These recommendations also include the role of novel oral anticoagulants, the problem of recurrences or the key risk factors identified in these subjects. This document reflects the first 21, referring to the areas of: diagnosis, evaluation and treatment of primary APS. The document provides a table of recommendations and treatment algorithms.

CONCLUSIONS

An update of the SER recommendations on APS is presented. This document corresponds to partI, related to diagnosis, evaluation and treatment. These recommendations are considered tools for decision-making for clinicians, taking into consideration both the decision of the physician experienced in APS and the patient. A partII has also been prepared, which addresses aspects related to obstetric SAF and special situations.

Seronegative antiphospholipid syndrome: refining the value of "non-criteria" antibodies for diagnosis and clinical management

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by arterial and venous thrombotic manifestations and/or pregnancy-related complications in patients with persistently high antiphospholipid antibodies (aPL), the most common being represented by anticardiolipin antibodies (aCL), anti-beta 2 glycoprotein-I (aβ2GPI), and lupus anticoagulant (LAC). A growing number of studies have showed that, in some cases, patients may present with clinical features of APS but with temporary positive or persistently negative titers of aPL. For these patients, the definition of seronegative APS (SN-APS) has been proposed. Nevertheless, the negativity to classic aPL criteria does not imply that other antibodies may be present or involved in the onset of thrombosis. The diagnosis of SN-APS is usually made by exclusion, but its recognition is important to adopt the most appropriate anti-thrombotic strategy to reduce the rate of recurrences. This research is in continuous development as the clinical relevance of these antibodies is far from being completely clarified. The most studied antibodies are those against phosphatidylethanolamine, phosphatidic acid, phosphatidylserine, phosphatidylinositol, vimentin/cardiolipin complex, and annexin A5. Moreover, the assays to measure the levels of these antibodies have not yet been standardized. In this review, we will summarize the evidence on the most studied non-criteria aPL, their potential clinical relevance, and the antithrombotic therapeutic strategies available in the setting of APS and SN-APS.

Direct oral anticoagulants in patients with antiphospholipid syndrome: a cohort study

Objectives

Despite controversies, direct oral anticoagulants (DOACs) are increasingly used in antiphospholipid syndrome (APS). We investigated the safety and efficacy of DOACs versus vitamin K antagonists (VKAs) in real-life consecutive APS patients.

Patients and methods

In a cohort study of 176 APS patients, which included 82 subjects who preferred DOACs or had unstable anticoagulation with VKAs, we recorded venous thromboembolism (VTE), cerebrovascular ischemic events or myocardial infarction, along with major bleeding or clinically relevant non-major bleeding (CRNMB).

Results

APS patients were followed for a median time of 51 (interquartile range 43–63) months. Patients on DOACs and those on VKAs were similar with regard to baseline characteristics. APS patients treated with DOACs had increased risk of recurrent thromboembolic events and recurrent VTE alone compared with those on VKAs (hazard ratio (HR) = 3.98, 95% confidence interval (CI): 1.54–10.28, p = 0.004 and HR = 3.69, 95% CI: 1.27–10.68, p = 0.016, respectively) with no differences between rivaroxaban and apixaban or single- or double-positive and triple-positive APS. Thromboembolism on DOACs was associated with older age (median 52 versus 42 years, p = 0.008) and higher global APS score (median 13 versus 8.5, p = 0.013). Patients on DOACs had increased risk of major bleeding or CRNMB (HR = 3.63, 95% CI: 1.53–8.63, p = 0.003), but rates of gastrointestinal bleeds (HR = 3.36, 95% CI: 0.70–16.16, p = 0.13) and major bleeds or CRNMB other than heavy menstrual bleeding (HR = 2.45, 95% CI: 0.62–9.69, p = 0.2) were similar in both treatment groups.

Conclusion

During long-term follow-up of real-life APS patients, DOACs are less effective and less safe as VKAs in the prevention of thromboembolism.

Role of direct oral anticoagulants in patients with kidney disease

The anticoagulation field is experiencing a renaissance that began with regulatory approval of the direct thrombin inhibitor dabigatran, a direct oral anticoagulant (DOAC), in 2010. The DOAC medication class has rapidly evolved to include the additional approval of 4 direct factor Xa inhibitors. Commensurately, DOAC use has increased and collectively account for the majority of new anticoagulant prescriptions. Despite exclusion of patients with moderate-to-severe kidney disease from most pivotal DOAC trials, DOACs are increasingly used in this setting. An advantage of DOACs is similar or improved antithrombotic efficacy with less bleeding risk when compared with traditional agents. Several post hoc analyses, retrospective studies, claims data studies, and meta-analyses suggest that these benefits extend to patients with kidney disease. However, the lack of randomized controlled trial data in specific kidney disease settings, with their unique pathophysiology, should be a call to action for the kidney community to systematically study these agents, especially because early data suggest that DOACs may pose less risk of anticoagulant-related nephropathy than do vitamin K antagonists. Most DOACs are renally cleared and are significantly protein bound in circulation; thus, the pharmacokinetics of these drugs are influenced by reduced renal function and proteinuria. DOACs are susceptible to altered metabolism by P-glycoprotein inhibitors and inducers, including drugs commonly used for the management of kidney disease comorbidities. We summarize the currently available literature on DOAC use in kidney disease and illustrate knowledge gaps that represent important opportunities for prospective investigation.

Antiphospholipid syndrome

Antiphospholipid syndrome is an autoimmune systemic disorder characterized by arterial, venous, or small vessel thrombosis and/or recurrent early pregnancy loss, fetal loss, or pregnancy morbidity in the setting of documented persistent antiphospholipid antibodies that include the lupus anticoagulant, or moderate-high titer anticardiolipin, or anti-β2Glycoprotein I antibodies. Associated clinical manifestations include livedo reticularis, cutaneous ulcerations, thrombocytopenia, hemolytic anemia, valvular heart disease, and nephropathy. The degree of risk associated with antiphospholipid antibody depends on the characteristics of the antiphospholipid antibody profile and on the presence of additional thrombotic risk factors. Current standard treatment for unprovoked thrombosis is long-term warfarin or other vitamin K antagonist therapy. Treatment to prevent recurrent obstetric complications is low-dose aspirin and prophylactic heparin, usually low-molecular-weight heparin. Optimal treatment for standard therapy failures or for certain nonthrombotic manifestations is uncertain, although nonanticoagulation therapies that address multiple demonstrated mechanisms of disease are being explored.

[Bilateral adrenal hemorrhage under apixaban in primary antiphospholipid syndrome]

INTRODUCTION

Adrenal hemorrhage is a classical but rare complication of antiphospholipid syndrome, revealing diagnosis in one third of the cases. Anti-vitamin K therapy is the standard treatment but direct oral anticoagulants are discussed as an alternative. In the latest recommendations, it is advised not to use direct oral anticoagulants in the setting of antiphospholipid syndrome.

CASE REPORT

We present a case of bilateral adrenal hemorrhage revealing primary antiphospholipid syndrome with triple positive antibody profile, in a 47-year-old man treated by apixaban for previous venous thromboembolism.

CONCLUSION

To our knowledge, it is the first case of adrenal hemorrhage occurring during apixaban treatment in a patient with antiphospholipid syndrome. This case illustrates the inefficacy of direct oral anticoagulants to prevent thrombotic events in antiphospholipid syndrome, in accordance with the latest recommendations.

Treatment in thrombotic antiphospholipid syndrome: a review

Antiphospholipid syndrome an autoimmune disease characterized by thrombosis and/or pregnancy morbidity alongside the presence of antiphospholipid antibodies (aPL). This review evaluates primary and secondary thromboprophylaxis in patients with aPL and thrombotic events. In primary thromboprophylaxis a risk-stratified approach is needed based on aPL, comorbidity with other autoimmune conditions and cardiovascular vascular risk factors. In primary thromboprophylaxis, the efficacy of low-dose aspirin is debatable and requires better-designed controlled studies. So far warfarin has not been shown to improve venous and/or arterial thrombosis incidence in aPL carriers and instead increased safety concerns. The benefit of hydroxychloroquine is inconclusive despite promising data, requiring large, controlled trials. For secondary thromboprophylaxis warfarin seems to be the best option with potential in renal transplant recipients and better efficacy at high intensity, although maintenance of target international normalized ratio needs careful monitoring. Aspirin has not shown to be beneficial, and data on rivaroxaban are limited and contradictory. Despite all data being informative, there are limitations that need to be addressed with robust clinical trials.

Comparing APLS and oranges: caution with the use of direct-acting oral anticoagulants (DOACs) instead of warfarin in the treatment of antiphospholipid syndrome (APLS)

A 63-year-old woman with known antiphospholipid syndrome (APLS) presented with catastrophic APLS and multiorgan dysfunction after a change in her anticoagulation from warfarin to rivaroxaban. Evidence suggests direct-acting oral anticoagulants (DOACs) like rivaroxaban may be less effective than warfarin in secondary prevention of thrombotic events in high-risk APLS patients.

Management of antiphospholipid syndrome

Antiphospholipid syndrome, also known as 'Hughes Syndrome', is an autoimmune disease characterised by a set of clinical manifestations, almost all of which are direct or indirect sequelae of a hypercoagulable state involving the venous, and to a lesser extent the arterial vasculature. The incidence and prevalence of antiphospholipid syndrome are estimated at approximately 5 de novo cases per 100 000 per year and 40-50 cases per 100 000 individuals, respectively. The clinical spectrum of antiphospholipid syndrome involves haematological (thrombocytopaenia, venous thrombosis), obstetrical (recurrent pregnancy loss), neurological (stroke, transient ischaemic attack, migraine, seizures, cognitive dysfunction, chorea, transverse myelitis, multiple sclerosis), cardiovascular (cardiac valve disease), dermatological (livedo reticularis and racemosa, skin ulceration and necrosis), renal (glomerulonephritis, renal thrombotic microangiopathy) and orthopaedic (avascular necrosis of bones, non-traumatic fractures) manifestations, among others. In addition to the classical antiphospholipid antibodies, namely anticardiolipin antibodies and lupus anticoagulant, new autoantibodies and antibody complexes of different immunoglobulin subtypes (IgA, IgG, IgM) are now recognised as significant contributors to the pathogenesis of antiphospholipid syndrome. Anticoagulation remains the cornerstone in the management of antiphospholipid syndrome; nevertheless, new drugs and therapeutic strategies are being tested, and some have been found effective for the primary and secondary thromboprophylaxis in antiphospholipid syndrome.

Antiplatelet and anticoagulant agents for primary prevention of thrombosis in individuals with antiphospholipid antibodies

BACKGROUND

Antiphospholipid syndrome (APS) is an autoimmune disease characterised by the presence of antiphospholipid (aPL) antibodies that have prothrombotic activity. Antiphospholipid antibodies are associated with an increased risk of pregnancy complications (recurrent miscarriage, premature birth, intrauterine growth retardation) and thrombotic events (both arterial and venous). The most common thrombotic events include brain ischaemia (stroke or transient ischaemic attack) and deep vein thrombosis. To diagnose APS, the presence of aPL antibodies in two measurements and at least one thrombotic event or pregnancy complication are required. It is unclear if people with positive aPL antibodies but without any previous thrombotic events should receive primary antithrombotic prophylaxis.

OBJECTIVES

To assess the effects of antiplatelet or anticoagulant agents versus placebo or no intervention or other intervention on the development of thrombosis in people with aPL antibodies who have not had a thrombotic event. We did not address obstetric outcomes in this review as these have been thoroughly addressed by other Cochrane Reviews.

SEARCH METHODS

We searched the Cochrane Vascular Specialised Register (4 December 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (last search 29 November 2017), MEDLINE Ovid, Embase Ovid, CINAHL, and AMED (searched 4 December 2017), and trials registries (searched 29 November 2017). We also checked reference lists of included studies, systematic reviews, and practice guidelines, and contacted experts in the field.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any antiplatelet or anticoagulant agents, or their combinations, at any dose and mode of delivery with placebo, no intervention, or other intervention. We also included RCTs that compared antiplatelet or anticoagulant agents with each other or that compared two different doses of the same drug. We included studies performed in people of any age and with no history of thrombosis (as defined by APS Sapporo classification criteria or updated Sydney classification criteria), but with aPL antibodies confirmed on at last two separate measurements. The studies included both pregnant women who tested positive for aPL antibodies and had a history of recurrent obstetric complications, as well as non-pregnancy related cases with positive screening for antibodies, in accordance with the criteria mentioned above.

DATA COLLECTION AND ANALYSIS

Pairs of authors independently selected studies for inclusion, extracted data, and assessed the risk of bias for the included studies and quality of evidence using GRADE. Any discrepancies were resolved through discussion or by consulting a third review author when necessary. In addition, one review author checked all the extracted numerical data.

MAIN RESULTS

We included nine studies involving 1044 randomised participants. The studies took place in several countries and had different funding sources. No study was at low risk of bias in all domains. We classified all included studies as at unclear or high risk of bias in two or more domains. Seven included studies focused mainly on obstetric outcomes. One study included non-pregnancy-related cases, and one study included both pregnancy-related cases and other patients with positive results for aPL antibodies. The remaining studies concerned women with aPL antibodies and a history of pregnancy failure. Four studies compared anticoagulant with or without acetylsalicylic acid (ASA) versus ASA only and observed no clear difference in thrombosis risk (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.25 to 3.77; 4 studies; 493 participants; low-quality evidence). No major bleeding was reported, but minor bleeding risk (nasal bleeding, menorrhagia) was higher in the anticoagulant with ASA group as compared with ASA alone in one study (RR 22.45, 95% CI 1.34 to 374.81; 1 study; 164 participants; low-quality evidence). In one study ASA was compared with placebo, and there were no clear differences in thrombosis (RR 5.21, 95% CI 0.63 to 42.97; 1 study; 98 participants; low-quality evidence) or minor bleeding risk between the groups (RR 3.13, 95% CI 0.34 to 29.01; 1 study; 98 participants; low-quality evidence), and no major bleeding was observed. Two studies compared ASA with low molecular weight heparin (LMWH) versus placebo or intravenous immunoglobulin (IVIG), and no thrombotic events were observed in any of the groups. Moreover, there were no clear differences in the risk of bleeding requiring transfusion (RR 9.0, 95% CI 0.49 to 164.76; 1 study; 180 participants; moderate-quality evidence) or postpartum bleeding (RR 1.30, 95% CI 0.60 to 2.81; 1 study; 180 participants; moderate-quality evidence) between the groups. Two studies compared ASA with high-dose LMWH versus ASA with low-dose LMWF or unfractionated heparin (UFH); no thrombotic events or major bleeding was reported. Mortality and quality of life data were not reported for any of the comparisons.

AUTHORS' CONCLUSIONS

There is insufficient evidence to demonstrate benefit or harm of using anticoagulants with or without ASA versus ASA alone in people with aPL antibodies and a history of recurrent pregnancy loss and with no such history; ASA versus placebo in people with aPL antibodies; and ASA with LMWH versus placebo or IVIG, and ASA with high-dose LMWH versus ASA with low-dose LMWH or UFH, in women with aPL antibodies and a history of recurrent pregnancy loss, for the primary prevention of thrombotic events. In a mixed population of people with a history of previous pregnancy loss and without such a history treated with anticoagulant combined with ASA, the incidence of minor bleeding (nasal bleeding, menorrhagia) was increased when compared with ASA alone. Studies that are adequately powered and that focus mainly on thrombotic events are needed to draw any firm conclusions on the primary prevention of thrombotic events in people with antiphospholipid antibodies.

Anticoagulation in a patient with antiphospholipid syndrome and a mechanical heart valve: a case study

: A case report of a patient with antiphospholipid syndrome (APS) with positive lupus anticoagulant and a mechanical mitral valve replacement (MVR) who presented with a thrombosis and difficult-to-control INRs. Current literature on anticoagulation options for patients who present with these conditions as well as alternate laboratory assays are reviewed. APS can present a unique complexity and challenge to appropriate anticoagulation on warfarin. Although there are emerging data regarding the use of novel oral anticoagulants to treat this condition, they do not justify their use in a patient with APS and an MVR because of a current lack of evidence. CFX testing may be used to calibrate INRs when there is a concern for false readings because of lupus anticoagulant interaction with INR assays.

Use of direct oral anticoagulants in antiphospholipid syndrome

The direct oral anticoagulants (DOACs) are therapeutic alternatives to warfarin and other vitamin K antagonists (VKAs), and constitute the standard of care for many indications. VKAs constitute the conventional therapy for the treatment and secondary thromboprophylaxis of thrombotic antiphospholipid syndrome (APS), but are often problematic, owing to the variable sensitivity of thromboplastins to lupus anticoagulant. Thus, the International Normalized Ratio may not accurately reflect anticoagulation intensity, or be clinically effective. Definition of the current role of DOACs in the treatment of APS is based on limited clinical trial data and information from other sources, including manufacturers' data, case series or cohort studies, and expert consensus. The Rivaroxaban in Antiphospholipid Syndrome (RAPS) randomized controlled trial (RCT), which had a laboratory surrogate primary outcome measure, suggests that rivaroxaban has the potential to be an effective and convenient alternative to warfarin in thrombotic APS patients with a single venous thromboembolism event requiring standard-intensity anticoagulation. However, further studies, in particular to provide better long-term efficacy and safety data, are needed before it can be widely recommended. APS patients are clinically heterogeneous, with the risk of recurrent thrombosis and the intensity of anticoagulation being influenced by their clinical phenotype and risk profile. DOAC trials involving homogeneous thrombotic APS populations, with the antiphospholipid antibody status well defined, will help to optimize the appropriate treatment in APS patient subgroups. Ongoing and emerging DOAC RCTs should provide further information to guide the use of DOACs in APS patients. Optimal identification of APS patients is a key step in working towards improved therapeutic strategies in these individuals.

Neurologic manifestations of antiphospholipid syndrome

Neurological involvement in antiphospholipid antibody syndrome (APS) is common, and its occurrence increases morbidity and mortality. Patients may present variable neurological involvement, such as cerebrovascular disease, cognitive dysfunction, headache, seizures, movement disorders, multiple sclerosis-like syndrome, transverse myelitis and ocular symptoms. Most neurological manifestations are associated with thrombosis of the microcirculation or of large vessels; nonetheless, there is compelling evidence suggesting that, in some cases, symptoms are secondary to an immune-mediated pathogenesis, with direct binding of aPL on neurons and glia. Herein we describe clinical characteristics and management of neurological APS manifestations.