Direct oral anticoagulants in antiphospholipid syndrome: Meta-analysis of randomized controlled trials

Thrombin Generation Assay in Antiphospholipid Antibodies Positive Subjects as a Personalized Thrombotic Risk Assessment: State of the Art and Perspectives

PURPOSE OF THE REVIEW

Thrombotic risk assessment in antiphospholipid positive (aPL +) subjects is a major challenge, and the study of in vitro thrombin generation (thrombin generation assays (TGA)) could provide useful information. Activated protein C (APC) sensitivity is involved in thrombotic events in antiphospholipid syndrome patients. We summarized methods used to assess APC sensitivity with TGA and evaluated the prognostic role of APC resistance through literature search.

RECENT FINDINGS

APC resistance induced by aPL is a complex pathway. Several cross-sectional studies assessed APC sensitivity to understand thrombotic event mechanisms in aPL + subjects. Only one prospective cohort had investigated the prognostic impact of APC resistance in aPL + subjects, with a positive and significant correlation between APC sensitivity and the risk of thrombosis during the follow up (hazard ratio, 6.07 [95% CI, 1.69-21.87]). APC resistance assessed with TGA could be associated with thrombotic events in aPL + subjects.

Between a rock and a hard place: resumption of oral anticoagulant therapy after intracranial hemorrhage

Intracranial hemorrhage (ICH) is the most feared and lethal complication of oral anticoagulant (OAC) therapy. Resumption of OAC after ICH has long posed a challenge for clinicians, complicated by the expanding range of anticoagulant agents available in modern clinical practice, including direct OACs and, more recently, factor XI and XII inhibitors. A review of the current literature found support for resuming OAC in the majority of patients after ICH based on pooled retrospective data showing that resumption is associated with a lower risk of mortality and thromboembolism without a significantly increased risk of recurrent hemorrhage. The optimal time to resume OAC is less clear; however, the available evidence suggests that the composite risk of both recurrent hemorrhage and thromboembolism is likely minimized, somewhere between 4 and 6 weeks, after ICH in most patients. Specific considerations to guide the optimal resumption time in the individual patient include ICH location, mechanism, and anticoagulant class. Patients with mechanical heart valves and intracerebral malignancy represent high-risk groups who require more nuanced decision making. Here, we appraise the literature with the aim of providing a practical guide for clinicians while also discussing priorities for future investigation.

Anticoagulant and non-anticoagulant therapy in thrombotic antiphospholipid syndrome: old drugs and new treatment targets

In this review, we discuss the current evidence on classic and newer oral anticoagulant therapy, older drugs such as HCQ and statins, and new potential treatment targets in APS. Vitamin K antagonists (VKAs) remain the cornerstone treatment for thrombotic events in APS. In patients fulfilling criteria for definite APS presenting with a first venous thrombosis, treatment with VKAs with a target international normalized ratio (INR) 2.0-3.0 is recommended. In patients with arterial thrombosis, treatment with VKA with target INR 2.0-3.0 or 3.0-4.0 is recommended by recent guidelines, considering the individual's bleeding and thrombosis recurrence risk. A combination of VKAs and low-dose aspirin (75-100 mg/daily) may also be considered. According to available evidence direct oral anticoagulants should be avoided in patients with arterial thrombosis and/or those with triple aPL positivity. Adjunctive treatment with HCQ and/or statins can be considered, especially in anticoagulation treatment-refractory APS. Potential targeted treatments in APS include B-cell targeting, complement inhibition, mammalian target of rapamycin inhibition, IFN targeting, adenosine receptors agonists, CD38 targeting or chimeric antigen receptor T-cell therapy. The safety and efficacy of these treatment targets needs to be examined in well-designed randomized controlled trials.

[Splanchnic vein thrombosis]

Splanchnic vein thrombosis includes Budd-Chiari syndrome and portal vein thrombosis. These diseases share common features: (i) they are rare diseases and (ii) they can lead to portal hypertension and its complications. Budd-Chiari syndrome and portal vein thrombosis in the absence of underlying liver disease share many risk factors, the most common being myeloproliferative neoplasms. A rapid and comprehensive workup for thrombosis risk factors is necessary in these patients. Long-term anticoagulation is indicated in most patients. Portal vein thrombosis can also develop in patients with cirrhosis, and is associated with a worse course of cirrhosis. Indications for anticoagulation in patients with cirrhosis are increasing. Transjugular intrahepatic portosystemic shunt is a second-line procedure in this setting. Because of the rarity of these diseases, high-level evidence studies are rare. However, collaborative studies have provided a better understanding of their natural history and allowed to improve the management of these patients. This review focuses on the causes, diagnosis, and management of patients with Budd-Chiari syndrome, patients with portal vein thrombosis without underlying liver disease, and patients with cirrhosis and portal vein thrombosis.

Bleeding events in thrombotic antiphospholipid syndrome: prevalence, severity, and associated damage accrual

Background

Life-long anticoagulation increases bleeding risk in patients with antiphospholipid syndrome (APS). The Damage Index for Antiphospholipid Syndrome does not include bleeding events in damage accrual.

Objectives

We aimed to characterize the prevalence, severity, and damage associated with bleeding events in patients with APS.

Methods

This was a single-center retrospective analysis of patients with thrombotic APS (2006 Sydney criteria). Bleeding events were reviewed up to 43 years and classified according to the ISTH definitions into 2 groups: 1) major bleedings and 2) nonmajor bleedings (minor bleedings and clinically relevant nonmajor bleedings). Damage events were recorded as bleeding events a) resulting in permanent (>6 months) decrease in organ function and b) complicated by total/partial organ resection.

Results

Among 197 patients (2412 patient-years [PYs] of follow-up), all of whom had been exposed to antithrombotic therapy, 40.6% experienced 167 bleedings (6.9 events per 100 PYs), of whom 61.3% had nonmajor bleedings (77.2% of bleedings: 42.6% minor, 57.4% clinically relevant nonmajor) and 38.8% had major bleedings (22.8% of bleedings; 1.6 events per 100 PYs). Soft/connective tissue was affected in 44.3% of bleedings, and 94.6% were nonmajor bleedings. Central nervous system was affected in 20.9% of bleedings, and 62.9% were major bleedings. Bleeding events were spontaneous in 90.4% of cases, and thrombocytopenia was likely involved in 62.2% of bleedings. Damage occurred in 11.4% of bleedings and affected 7.6% of patients. Most of the damage was associated with central nervous system events (8.4% of all bleedings).

Conclusion

Approximately 40% of patients experienced at least 1 bleeding, and almost 8% of patients were left with organ damage not recognized by the current version of the Damage Index for Antiphospholipid Syndrome.

Prevalence of antiphospholipid antibody syndrome misclassification in an academic health system

PURPOSE

Antiphospholipid Antibody Syndrome (APS) is a complex autoimmune disorder that includes a combination of laboratory criteria and clinical events (thrombosis, pregnancy complications). Accurate classification is essential, as APS patients may have limited oral anticoagulant options and requires indefinite anticoagulation. The prevalence of inaccurate APS misclassification is unknown. This study sought to determine the proportion of patients in an academic health-system who formally met APS criteria.

METHODS

This retrospective cohort study included any patient within the University of Utah Health system who had an International Classification of Diseases-10 code for APS, between January 1, 2016 and June 30, 2020. Manual chart review was performed to assess the appropriateness of the APS classification by laboratory and clinical criteria.

RESULTS

Of the 184 patients identified, 59 (32.1 %) formally met APS criteria, while 69 (37.5 %) did not meet criteria. The remaining 56 (30.4 %) patients lacked enough information in their medical records to decide on appropriateness of APS classification. The most prevalent reason for inappropriate APS classification in the 69 patients identified was incorrect interpretation of lab values as positive (62; 89.9 %), followed by lack of repeat confirmation testing (32; 46.4 %).

CONCLUSION

The results of this single-center study indicate that only one-third of patients with presumed APS met classification criteria. This was predominantly due to incorrect collection or interpretation of APS laboratory data. One-third had insufficient medical record data to determine APS classification, which impairs clinical decision-making. This suggests more education or implementation of anticoagulation stewardship is needed to ensure accurate APS classification and proper management of anticoagulation therapy.

Therapy with direct oral anticoagulants for secondary prevention of thromboembolic events in the antiphospholipid syndrome: a systematic review and meta-analysis of randomised trials

OBJECTIVE

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterised by venous thrombosis (VT) or arterial thrombosis (AT) and/or pregnancy morbidity and the presence of antiphospholipid antibodies. Direct oral anticoagulants (DOACs) hold several advantages to vitamin K antagonists (VKAs) for prevention of thrombosis and we wish to evaluate DOACs compared with VKAs in secondary prevention of thromboembolic events in patients with APS.

METHODS

We conducted searches of the published literature using relevant data sources (MEDLINE, Embase and Cochrane CENTRAL), and of trial registers for unpublished data and ongoing trials. We included randomised trials examining individuals >18 years with APS classified according to the criteria valid when the trial was carried out. Randomised controlled trials had to examine any DOAC agent compared with any comparable drug. We tabulated all occurrences of events from all eligible randomised trials. Due to few events, ORs and 95% CIs were calculated using the Peto method.

RESULTS

5 randomised trials comprising 624 patients met the predefined eligibility criteria. The primary outcome measure was new thrombotic events, a composite endpoint of any VT or AT, during the VKA-controlled phase of treatment. According to the I2 inconsistency index, there was evidence of statistical heterogeneity across the studies (I2=60%). Across trials, 29 and 10 thrombotic events were observed in 305 and 319 patients with APS treated with DOAC and VKA, respectively, corresponding to a combined Peto OR of 3.01 (95% CI 1.56 to 5.78, p=0.001). There was a significantly increased risk of AT while treated with DOACs compared with VKA (OR 5.5 (2.5, 12.1) p<0.0001), but no difference in the risk of VT (p=0.87). We found no significant difference in risk of bleeding.

CONCLUSIONS

DOACs were associated with a significant increase in the risk of a new thrombotic event, especially AT, favouring standard prophylaxis with warfarin.

PROSPERO REGISTRATION NUMBER

CRD42019126720.

Survey on antiphospholipid syndrome diagnosis and antithrombotic treatment in patients with ischemic stroke, other brain ischemic injury, or arterial thromboembolism in other sites: communication from ISTH SSC Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibodies

BACKGROUND

The optimal strategy for diagnosis and antithrombotic treatment of patients with antiphospholipid syndrome (APS)-associated acute ischemic stroke (AIS), transient ischemic attack (TIA), or other brain ischemic injury is poorly defined.

OBJECTIVES

The survey goal was to capture variations in diagnosis and antithrombotic treatment of APS-associated ischemic stroke and related disorders to inform guidance and clinical trials to define optimal management.

METHODS

Professional colleagues, including key opinion leaders, were invited to complete a REDCap survey questionnaire initiated by the International Society on Thrombosis and Haemostasis Scientific and Standardisation Committee Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibodies. The survey data were tallied using simple descriptive statistics.

RESULTS

There was generally good agreement on several aspects, including which patients to test for antiphospholipid antibodies (aPL), use of a lifelong vitamin K antagonist for AIS or recurrent TIA, and formal cognitive assessment for suspected cognitive impairment. There was less agreement on other aspects, including aPL testing for brain ischemic injury other than AIS/TIA or if an alternative cause for AIS or TIA exists; choice of aPL tests, their timing, and age cutoff; the aPL phenotype to trigger antithrombotic treatment; management for patent foramen ovale; antithrombotic treatment for first TIA or white matter hyperintensities; head magnetic resonance imaging specifications; and low-molecular-weight heparin dosing/anti-Xa monitoring in pregnancy. The survey highlighted that approximately 25% practice at dedicated APS clinics and <50% have a multidisciplinary team structure for patients with APS.

CONCLUSION

Much of the variation in practice reflects the lack of evidence-based recommendations. The survey results should inform the development of a more uniform multidisciplinary consensus approach to diagnosis and antithrombotic treatment.

Multimodality approach to treat calciphylaxis in end-stage kidney disease patients

A multimodality approach has been proposed as an effective treatment for calciphylaxis in patients with end-stage kidney disease. In this retrospective study, we report the cases of 12 end-stage kidney disease patients from l'Hôtel-Dieu de Québec hospital (Canada) who were diagnosed with calciphylaxis between 2004 and 2012 and treated with a multimodality clinical approach including sodium thiosulfate (STS). Statistical analyses were performed to evaluate the impacts of patients characteristics, the different interventions as well as therapy regimen on the therapeutic response. The majority of patients (n = 9) were hemodialyzed. The patients-associated comorbidities were consistent with previously reported risk factors for calciphylaxis: Diabetes (n = 11), calcium-based phosphate binders use (n = 10), warfarin use (n = 9), obesity (n = 7), female gender (n = 8) and intravenous iron use (n = 8). STS was given for a median duration of 81 days. 75% of the patients had a response (total or partial) including a complete response in 42% of patients. One-year mortality rate was low (25%). STS was used during a mean duration of 83.33 ± 41.52 days and with a total cumulating dose of 1129.00 ± 490.58 g. The recorded mean time before a complete response was 102.20 days (51-143). Pain improvement occurred after a mean time of 8.67 ± 10.06 days. None of the studied factors was statistically associated with a complete or a partial response to the multimodality approach. Although our data have a limited statistical power, they support treating calciphylaxis with a multimodality approach including STS as its effects are independent from important clinical variables.

High prevalence of thrombophilic risk factors in patients with central retinal artery occlusion

INTRODUCTION

Central retinal artery occlusion (CRAO) is a common cause of blindness and visual morbidity. In the majority of cases, it is related to thrombotic embolism. Nevertheless, the role of inherited or acquired thrombophilic risk factors in CRAO pathogenesis has not been comprehensively studied.

METHODS

In 126 CRAO patients (66 [52.4%] men, median age 55 [range: 18-80] years) and 107 matched controls (56 [52.3%] men, median age 53 [range: 34-78] years) we evaluated classical atherosclerotic risk factors, including serum lipid profile and glucose level, analyzed intima-media complex thickness (IMT) of external carotid arteries, and performed transthoracic echocardiography. Furthermore, we established the prevalence of inherited and acquired thrombophilic risk factors, such as factor V Leiden (FVL) and prothrombin 20210 G/A genetic variants, plasma activity of factor (F) VIII, protein C and antithrombin activity, and free protein S levels. We also assessed the presence of antiphospholipid antibodies (APLA) and evaluated blood homocysteine in all enrolled subjects. Additionally, we estimated the occurrence of Val34Leu polymorphism of the A subunit of coagulation factor XIII (FXIII-A) in both groups as a potential thrombosis-protecting factor.

RESULTS

Among traditional atherosclerotic risk components, obesity/overweight and hypercholesterolemia were the most common in the CRAO group and occurred in 103 (81.7%) and 85 (67.5%) patients, respectively. CRAO patients also had elevated IMT and altered echocardiographic parameters, indicating diastolic cardiac dysfunction. In thrombophilia investigations, at least one laboratory risk factor occurred in 72.2% (n = 91) of CRAO patients, with APLA as the most frequent, detected in 38.1% (n = 48) of them (almost seven times more frequent than in controls, p < 0.001). Deficiencies in protein C activity and free protein S levels were also common in the CRAO group, reported in 17.5% (n = 22) and 19.8% (n = 25) of patients, respectively. Interestingly, among two analyzed prothrombotic genetic variants, only the FVL was related to CRAO, with the allelic frequency 2.4 times more prevalent than in controls (p = 0.044). Finally, the CRAO group was characterized by hyperhomocysteinemia, almost twice as common as in controls (p = 0.026). Antithrombin deficiency, elevated FVIII, and FXIII-A Val34Leu polymorphism were not associated with CRAO.

CONCLUSIONS

Our findings suggest that thrombophilia plays a vital role in the pathogenesis of CRAO. Thus, proper laboratory screening should be considered in the primary and secondary prevention of those episodes, with implementing appropriate therapy as needed.

Direct oral anticoagulants vs. vitamin K antagonists in patients with antiphospholipid syndrome: a systematic review and meta-analysis

Optimal treatment regimen for patients with antiphospholipid syndrome (APS) remain unclear. Therefore, the authors sought to compare the outcomes of vitamin K antagonists (VKAs) vs. direct oral anticoagulants (DOACs) in patients with APS.

METHODS

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

RESULTS

The analysis included 625 patients from four randomized controlled trials and one post hoc analysis. Meta-analysis showed statistically non-significant difference between DOACs inhibitors and VKAs 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 the 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 positive [RR 4.12 (95% CI 0.46, 37.10); P=0.21, I2=58%]. DOACs inhibitors were significantly associated with increased risk of stroke [RR 8.51 (95% CI 2.35, 3.82); P=0.47, I2=0%].

CONCLUSION

DOACs exhibited increased risk of stroke among patients with APS. In addition, although not significant, the higher RRs among patients on DOACs may indicate higher risk of thrombotic events associated with DOACs.

Profile and outcome of patients with Warfarin Toxicity admitted in a tertiary care hospital in Bhutan: a cross-sectional study investigators and institutions

OBJECTIVE

To study the profile, clinical presentation and outcome of hospital stay among patients admitted with warfarin toxicity at the Jigme Dorji Wangchuck National Referral Hospital, Bhutan. This was a cross-sectional study with a review of hospital records of patients admitted between 01 and 2018 and 30 June 2020.

RESULTS

There were 22 admissions due to warfarin toxicity. The mean age of patients was 55.9 (± SD 20.2) years, the median duration of warfarin therapy was 30 months (IQR 4.8, 69 months). The indications for warfarin were atrial fibrillation (9, 40.9%), mechanical heart valves (6, 27.3%), deep vein thrombosis (6, 27.3%) and pulmonary thromboembolism (1, 4.5%). The mean of dosage of warfarin was 4.3 (± 2.6) mg and the cumulative dosage in the week prior to admission was 30.9 (± 18.6) mg. The mean of INR at presentation was 7.7 (± 4.3) with the maximum noted at 20. The patients presented with gastrointestinal bleeding, muscle haematomas, epistaxis and oral cavity bleeding. There was no mortality related to warfarin toxicity. The reasons for warfarin toxicity included patient dosing error and drug interactions. Warfarin therapy requires appropriate patient education, adequate facilities for follow-up and avoidance of warfarin wherever possible in clinical settings.

Stroke and Noninfective Native Valvular Disease

PURPOSE OF REVIEW

Embolic stroke of undetermined source is a challenging clinical entity. While less common than atrial fibrillation and endocarditis, many noninfective heart valve lesions have been associated with stroke and may be considered as culprits for cerebral infarcts when other more common causes are excluded. This review discusses the epidemiology, pathophysiology, and management of noninfective valvular diseases that are commonly associated with stroke.

RECENT FINDINGS

Calcific debris from degenerating aortic and mitral valves may embolize to the cerebral vasculature causing small- or large-vessel ischemia. Thrombus which may be adherent to calcified valvular structures or left-sided cardiac tumors may also embolize resulting in stroke. Tumors themselves, most commonly myxomas and papillary fibroelastomas, may fragment and travel to the cerebral vasculature. Despite this broad differential, many types of valve diseases are highly comorbid with atrial fibrillation and vascular atheromatous disease. Thus, a high index of suspicion for more common causes of stroke is needed, especially given that treatment for valvular lesions typically involves cardiac surgery whereas secondary prevention of stroke due to occult atrial fibrillation is readily accomplished with anticoagulation.

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.

Management of splanchnic vein thrombosis

The expression splanchnic vein thrombosis encompasses Budd-Chiari syndrome and portal vein thrombosis. These disorders have common characteristics: they are both rare diseases which can cause portal hypertension and its complications. Budd-Chiari syndrome and portal vein thrombosis in the absence of underlying liver disease share many risk factors, among which myeloproliferative neoplasms represent the most common; a rapid comprehensive work-up for risk factors of thrombosis is needed in these patients. Long-term anticoagulation is indicated in most patients. Portal vein thrombosis can also develop in patients with cirrhosis and in those with porto-sinusoidal vascular liver disease. The presence and nature of underlying liver disease impacts the management of portal vein thrombosis. Indications for anticoagulation in patients with cirrhosis are growing, while transjugular intrahepatic portosystemic shunt is now a second-line option. Due to the rarity of these diseases, studies yielding high-grade evidence are scarce. However, collaborative studies have provided new insight into the management of these patients. This article focuses on the causes, diagnosis, and management of patients with Budd-Chiari syndrome, portal vein thrombosis without underlying liver disease, or cirrhosis with non-malignant portal vein thrombosis.

Antiphospholipid syndrome, antiphospholipid antibodies, and stroke

Antiphospholipid syndrome (APS) is a prothrombotic autoimmune disease with heterogeneous clinicopathological manifestations and is a well-established cause of acute ischemic stroke (AIS) and transient ischemic attack (TIA), particularly in younger patients. There is growing recognition of a wider spectrum of APS-associated cerebrovascular lesions, including white matter hyperintensities, cortical atrophy, and infarcts, which may have clinically important neurocognitive sequalae. Diagnosis of APS-associated AIS/TIA requires expert review of clinical and laboratory information. Management poses challenges, given the potential for substantial morbidity and recurrent thrombosis, additional risk conferred by conventional cardiovascular risk factors, and limited evidence base regarding optimal antithrombotic therapy for secondary prevention. In this review, we summarize key features of APS-associated cerebrovascular disorders, with focus on clinical and laboratory aspects of diagnostic evaluation. The current status of prognostic markers is considered. We review the evidence base for antithrombotic treatment in APS-associated stroke and discuss uncertainties, including the optimal intensity of anticoagulation and efficacy of direct oral anticoagulants. Clinical practice recommendations are provided, covering antithrombotic treatment, supportive management, and options for anticoagulant-refractory cases, and we highlight the benefits of adopting a considered, multidisciplinary team approach.

Evolution of Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is an autoimmune prothrombotic disease characterized by thrombosis and/or pregnancy complications caused by antiphospholipid antibodies (aPL). The history of APS can be traced back to observations made during screening programs for syphilis conducted in the mid-20th century, with identification of patients with the so-called biological false-positive serological reactions for syphilis. Initial observation linking aPL with recurrent miscarriages was first reported more than 40 years ago. Since then, our understanding of the pathogenesis and management of APS has evolved markedly. Although APS is an autoimmune disease, anticoagulation mainly with vitamin K antagonists (VKAs) rather than immunomodulation, is the treatment of choice for thrombotic APS. Direct acting oral anticoagulants are inferior to VKAs, especially those with triple-positive APS and arterial thrombosis. Inflammation, complement activation, and thrombosis in the placenta may contribute to pathogenesis of obstetric APS. Heparin, mainly low-molecular-weight heparin, and low-dose aspirin represent the treatments of choice for women with obstetric complications. Increasingly, immunomodulatory agents such as hydroxychloroquine for thrombotic and obstetric APS are being used, especially in patients who are refractory to present standard treatment.

Antiphospholipid syndrome: advances in diagnosis, pathogenesis, and management

Antiphospholipid syndrome (APS) is a thrombo-inflammatory disease propelled by circulating autoantibodies that recognize cell surface phospholipids and phospholipid binding proteins. The result is an increased risk of thrombotic events, pregnancy morbidity, and various other autoimmune and inflammatory complications. Although antiphospholipid syndrome was first recognized in patients with lupus, the stand alone presentation of antiphospholipid syndrome is at least equally common. Overall, the diagnosis appears to affect at least one in 2000 people. Studies of antiphospholipid syndrome pathogenesis have long focused on logical candidates such as coagulation factors, endothelial cells, and platelets. Recent work has shed light on additional potential therapeutic targets within the innate immune system, including the complement system and neutrophil extracellular traps. Vitamin K antagonists remain the mainstay of treatment for most patients with thrombotic antiphospholipid syndrome and, based on current data, appear superior to the more targeted direct oral anticoagulants. The potential role of immunomodulatory treatments in antiphospholipid syndrome management is receiving increased attention. As for many systemic autoimmune diseases, the most important future direction is to more precisely identify mechanistic drivers of disease heterogeneity in pursuit of unlocking personalized and proactive treatments for patients.

Venous Thromboembolism in the Inflammatory Rheumatic Diseases

Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a cardiovascular event whose risk is increased in most inflammatory rheumatic diseases (IRDs). Mechanisms that increase VTE risk include antiphospholipid antibodies (APLs), particularly anticardiolipin antibodies, anti-beta2glycoprotein I antibodies and lupus anticoagulant present together, and inflammation-mediated endothelial injury. Patients with IRDs should receive long-term anticoagulation drugs when the risk of VTE recurrence is high. In the light of recent warnings from regulatory agencies regarding heightened VTE risk with Janus kinase inhibitors, these drugs should be initiated only after a careful assessment of VTE risk in those with IRDs.

Severe Libman-Sacks endocarditis complicating antiphospholipid syndrome: a retrospective analysis of 23 operated cases

OBJECTIVE

Data on severe heart valve disease (HVD), including Libman-Sacks endocarditis, associated with SLE and/or APS requiring valvular surgery are scarce. We thus conducted a retrospective study, aimed at describing and clarifying clinical, laboratory, echocardiographic, histopathological and evolutional features of SLE and/or APS patients with severe associated-HVD.

METHODS

An observational retrospective multicentric analysis of 23 adults with SLE and/or APS and HVD between 1996 and 2019 and available histopathological report evaluating long-term follow-up.

RESULTS

Twenty-three individuals (20 females, median age 37 [range 17-76] years) were included. All had APS (thrombotic in 22, with an arterial phenotype in 15 and with catastrophic APS [CAPS] in six), and 11 (47%) had SLE. Systemic underlying disease had been diagnosed prior to HVD in 12 (52%). In 10 patients (43%), HVD was complicated by cerebral stroke prior to surgery. Twenty patients (87%) had only one pathological valve, the mitral valve in 18 patients (78%). Valvular thickening (n = 19) and valvular regurgitation (n = 19) were the most frequently reported lesions. Fifteen (62%) patients underwent mechanical valve replacement, six (26%) conservative valve repair (five were later re-operated after a median time of 1 [0-4] year), and two (9%) underwent biological valve replacement. Nine patients (39%) presented early-onset post-operative complications, including three CAPS immediately after surgery and one death. After surgery, 18 patients (78%) had normal postoperative valvular function, but almost half of the patients (43%) had post-operative neurological sequelae (median follow-up of 6 [2-20] years).

CONCLUSION

Severe HVD leading to surgery was strongly associated with thrombotic APS, especially arterial phenotypes. Half of the reported patients presented cerebral stroke complicating the HVD. Valvular surgery carried a significant risk of CAPS.

Factor XI inhibitors: cardiovascular perspectives

Anticoagulants are the cornerstone for prevention and treatment of thrombosis but are not completely effective, and concerns about the risk of bleeding continue to limit their uptake. Animal studies and experience from patients with genetic coagulation factor XI deficiency suggesting that this factor is more important for thrombosis than for haemostasis raises the potential for drugs that target factor XI to provide safer anticoagulation. Multiple factor XI inhibitors are currently under evaluation in clinical trials, including parenterally administered antisense oligonucleotides, monoclonal antibodies, and orally active small-molecule inhibitors. Promising results of phase 2 trials in patients undergoing major orthopaedic surgery, and in those with end-stage kidney disease, atrial fibrillation and acute coronary syndromes have led to large phase 3 trials that are currently ongoing. We here review premises for the use of these agents, results so far accrued, ongoing studies, and perspectives for future patient care.

Comparing the efficacy and safety of direct oral anticoagulants versus Vitamin K antagonists in patients with antiphospholipid syndrome: a systematic review and meta-analysis

Thromboprophylaxis is the cornerstone strategy for thrombotic antiphospholipid syndrome (APS). Data comparing direct oral anticoagulants (DOACs) to Vitamin K antagonists (VKAs) in the secondary prevention of thrombosis in APS patients remain contentious. We aim to review and analyse literature on the efficacy and safety of DOACs compared with VKAs in treating patients with APS. A literature search was performed from inception to 31 December 2021. Subgroups were analysed based on the risk stratification of APS profiles and different DOAC types. A total of nine studies with 1131 patients were included in the meta-analysis. High-risk APS patients (triple positive APS) who used DOACs displayed an increased risk of recurrent thrombosis [risk ratio = 3.65, 95% confidence interval (95% CI): 1.49-8.93; I2  = 29%, P  = 0.005] compared with those taking VKAs. Similar risk of recurrent thrombosis or major bleeding was noted in low-risk APS patients (single or double antibody-positive) upon administering DOACs or VKAs. The utilization of Rivaroxaban was associated with a high risk of recurrent thromboses (RR = 2.63; 95% CI: 1.56-4.42; I2  = 0, P  = 0.0003), particularly recurrent arterial thromboses (RR = 4.52; 95% CI: 1.99-10.29; I2  = 0, P  = 0.18) in overall APS patients. Comparisons of the rate of recurrent thrombosis events and major bleeding events when using dabigatran or apixaban versus VKAs yielded no statistical differences. In the absence of contraindications, this meta-analysis suggests that VKAs remain the first-choice treatment for high-risk APS patients, with DOACs a more appropriate option for low-risk APS patients. Different DOACs may exhibit different levels of efficacy and safety for thromboprophylaxis in APS patients and require further exploration.

Efficacy and Safety of Direct Oral Anticoagulants in Patients With Antiphospholipid Syndrome: A Systematic Review and Meta-Analysis

Due to a high risk of recurrent thromboembolism in patients with antiphospholipid syndrome (APS), long-term anticoagulation is recommended. For decades, vitamin K antagonists (VKAs) have been the gold standard for thromboprophylaxis in these patients. Due to the widespread use of direct oral anticoagulants (DOACs) in various thromboembolic conditions and their potential advantages compared to VKAs, several studies have been conducted to evaluate their safety and efficacy in APS.

We performed a literature search using PubMed, Embase, and Cochrane databases for studies comparing DOACs to VKAs in patients with APS. Relative risk (RR) and the corresponding 95% confidence intervals (95% CI) were estimated for recurrent thromboembolic events, bleeding, and mortality.

A total of 1437 patients pooled from 12 studies were analyzed. The risk of recurrent thrombosis, especially arterial thrombosis, doubled with DOACs compared to VKAs (RR 2.61, 95% CI 1.44-4.71; p=0.001). The risk further increased in patients with a triple-positive antiphospholipid antibody profile (RR 4.50, 95% CI 1.91-10.63; p=0.0006) and with the use of rivaroxaban (RR 1.95, 95% CI 1.10-3.45; p=0.02). The risk of major bleeding and mortality were not significantly different between the two arms. A trend favoring DOACs compared to VKAs was observed for all bleeding events. 

This meta-analysis comes in agreement with previous studies and supports the use of VKAs in APS. Our study revealed that VKAs remain the gold standard for the management of APS, especially triple-positive APS. DOACs, particularly rivaroxaban, are not as effective in preventing recurrent thromboembolism in high-risk APS patients. Further studies are needed to evaluate the role of DOACs apart from rivaroxaban with a focus on their efficacy in the management of isolated or double-positive APS.

Direct oral anticoagulants versus warfarin in patients with antiphospholipid syndrome: A meta-analysis of randomized controlled trials

Objective

This study aimed to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) versus warfarin in patients with antiphospholipid syndrome (APS).

Methods

We performed a literature search using MEDLINE, EMBASE, and the Cochrane Controlled Trials Register. We also performed a meta-analysis of randomized controlled trials (RCTs) investigating the effectiveness and safety of DOACs versus warfarin in patients with APS.

Results

Five RCTs involving 648 patients with APS (330 in DOAC-treated and 318 in control groups) were included in the meta-analysis. Among the patients included in the analysis, 29 (8.8%) patients experienced recurrent thrombosis in the DOAC treatment group, and 10 patients (3.1%) had thrombosis recurrence in the warfarin treatment group, resulting in a higher incidence in DOAC-treated than in the warfarin-treated groups [odds ratio (OR) = 2.163, 95% CI = 0.985–4.748, p = 0.055]. Incidence of arterial thrombosis was significantly higher in DOAC-treated patients than in warfarin-treated patients (OR = 5.168, 95% CI = 1.567–17.04, p = 0.007). Stroke and thrombosis occurrences were significantly higher in the triple positivity group than in the warfarin therapy group (OR = 12.03, 95% CI = 2.249–64.36, p = 0.004; OR = 2.940, 95% CI = 1.016–8.504, p = 0.047). However, venous thrombosis occurrences did not differ significantly between the DOAC-treated and warfarin-treated groups. There were no significant differences between the DOAC and warfarin groups in terms of any bleeding, major bleeding, minor bleeding, and all-cause mortality.

Conclusion

DOACs were associated with higher rates of arterial thrombosis than warfarin in patients with APS, especially in the triple-positive group. However, a higher risk of recurrent venous thrombosis was not found in APS patients treated with DOACs compared to those treated with warfarin.

Splinters in the fingernails, heart and brain: thromboembolic complications of non-bacterial thrombotic endocarditis despite treatment with a direct-acting oral anticoagulant

Non-bacterial thrombotic endocarditis (NBTE) is a rare condition characterized by non-infectious vegetations affecting the cardiac valves. Although systemic thromboembolism is a commonly associated condition, antiphospholipid syndrome is less common. Nevertheless, treatment generally involves long-term anticoagulation. We report a case of a patient with previously undiagnosed NBTE who suffered systemic thromboembolic events despite pre-existing treatment with a direct-acting oral anticoagulant.

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.

Recent Advances in Anticoagulant Treatment of Immune Thrombosis: A Focus on Direct Oral Anticoagulants in Heparin-Induced Thrombocytopenia and Anti-Phospholipid Syndrome

For more than 10 years, direct oral anticoagulants (DOACs) have been increasingly prescribed for the prevention and treatment of thrombotic events. However, their use in immunothrombotic disorders, namely heparin-induced thrombocytopenia (HIT) and antiphospholipid syndrome (APS), is still under investigation. The prothrombotic state resulting from the autoimmune mechanism, multicellular activation, and platelet count decrease, constitutes similarities between HIT and APS. Moreover, they both share the complexity of the biological diagnosis. Current treatment of HIT firstly relies on parenteral non-heparin therapies, but DOACs have been included in American and French guidelines for a few years, providing the advantage of limiting the need for treatment monitoring. In APS, vitamin K antagonists are conversely the main treatment (+/− anti-platelet agents), and the use of DOACs is either subject to precautionary recommendations or is not recommended in severe APS. While some randomized controlled trials have been conducted regarding the use of DOACs in APS, only retrospective studies have examined HIT. In addition, vaccine-induced immune thrombotic thrombocytopenia (VITT) is now a part of immunothrombotic disorders, and guidelines have been created concerning an anticoagulant strategy in this case. This literature review aims to summarize available data on HIT, APS, and VITT treatments and define the use of DOACs in therapeutic strategies.

Direct oral anticoagulants versus vitamin K antagonists in patients with antiphospholipid syndrome: systematic review and meta-analysis

Background

Despite vitamin K antagonists (VKA) being the gold standard in the prevention of thromboembolic events in antiphospholipid syndrome (APS), non-vitamin K antagonists oral anticoagulants/direct oral anticoagulants (DOACs) have been used off-label.

Objective

We aimed to perform a systematic review comparing DOACs to VKA regarding prevention of thromboembolic events, occurrence of bleeding events and mortality in patients with APS.

Methods

An electronic database search was performed through MEDLINE, CENTRAL and Web of Science. After data extraction, we pooled the results using risk ratio (RR) and 95% CI. Heterogeneity was assessed using the I². The outcomes considered were all thromboembolic events as primary, and major bleeding, all bleeding events and mortality as secondary. Evidence confidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation methodology.

Results

We included 7 studies and a total of 835 patients for analyses. Thromboembolic events were significantly increased in DOACs arm, compared with VKA—RR 1.69, 95% CI 1.09 to 2.62, I²—24%, n=719, 6 studies. In studies using exclusively rivaroxaban, which was the most representative drug in all included studies, the thromboembolic risk was increased threefold (RR 3.36, 95% CI 1.53 to 7.37). The risks of major bleeding, all bleeding events and mortality were not significantly different from control arm. The grade of certainty of our results is very low.

Conclusions

Current evidence suggests DOACs use, particularly rivaroxaban, among patients with APS, is less effective than VKA since it is associated with 69% increased risk of thromboembolic events.

Trial registration number

CRD42020216178.

An arm and a leg: A case of rheumatoid vasculitis and antiphospholipid antibody syndrome

Rheumatoid vasculitis is a rare extra-articular complication of rheumatoid arthritis. The most common manifestation is cutaneous; however, it can manifest in various organ systems and is associated with a high degree of morbidity and mortality. Diagnosis is challenging, and there are no validated diagnostic or classification criteria. Most cases should be confirmed with tissue biopsy when possible given the severity of disease and the extent of immunosuppression required to treat this condition. We report the case of a 54-year-old white woman with long-standing, uncontrolled, and seropositive rheumatoid arthritis with a history of elevated anticardiolipin IgG and IgM antibodies who presented with acute stenosis of her left femoral artery which ultimately required a left above-the-knee amputation. Histopathology revealed findings consistent with vasculitis and thrombosis, and subsequent imaging revealed multifocal arterial and venous thromboses. She was diagnosed with rheumatoid vasculitis and antiphospholipid antibody syndrome, and was treated with high-dose glucocorticoids, cyclophosphamide, and warfarin. Rheumatoid vasculitis is a rare but devastating complication of rheumatoid arthritis, and vigilance for this condition must be maintained, especially in patients with long-standing, seropositive disease.