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

Antithrombotic therapy in antiphospholipid syndrome with arterial thrombosis: a systematic review and network meta-analysis

Introduction

The optimal secondary thromboprophylactic strategies for patients with antiphospholipid syndrome (APS) and arterial thrombosis remain controversial. This study aimed to evaluate the comparative efficacy and safety of various antithrombotic strategies in APS with arterial thrombosis.

Methods

A comprehensive literature search was conducted using OVID MEDLINE, EMBASE, Web of Science, and the Cochrane Controlled Register of Trials (CENTRAL) from inception until 30 September 2022, with no language restrictions. The inclusion criteria for eligible studies were as follows: inclusion of APS patients with arterial thrombosis, treatment with either antiplatelet agents, warfarin, direct oral anticoagulants (DOACs), or a combination of these therapies, and reporting of recurrent thrombotic events.

Results

We conducted a frequentist random-effects network meta-analysis (NMA) involving 13 studies with a total of 719 participants, comprising six randomized and seven non-randomized studies. In comparison to single antiplatelet therapy (SAPT), the combined use of antiplatelet and warfarin demonstrated a significant reduction in the risk of recurrent overall thrombosis, with a risk ratio (RR) of 0.41 (95% CI 0.20 to 0.85). Dual antiplatelet therapy (DAPT) showed a lower risk of recurrent arterial thrombosis compared to SAPT although the difference did not reach statistical significance, with an RR of 0.29 (95% CI 0.08 to 1.07). DOAC was associated with a significant increase in the risk of recurrent arterial thrombosis, with an RR of 4.06 (95% CI 1.33 to 12.40) when compared to SAPT. There was no significant difference in major bleeding among various antithrombotic strategies.

Discussion

Based on this NMA, the combination of warfarin and antiplatelet therapy appears to be an effective approach in preventing recurrent overall thrombosis in APS patients with a history of arterial thrombosis. While DAPT may also show promise in preventing recurrent arterial thrombosis, further studies are needed to confirm its efficacy. Conversely, the use of DOACs was found to significantly increase the risk of recurrent arterial thrombosis.

The digestive system involvement of antiphospholipid syndrome: pathophysiology, clinical characteristics, and treatment strategies

Antiphospholipid syndrome (APS) is an autoimmune disease mainly characterised by vascular thrombosis and pregnancy morbidity. APS has broad spectrum of clinical manifestations. The digestive system involvement of antiphospholipid syndrome is a critical but under-recognised condition. Digestive system involvement may be the result of direct (autoimmune-mediated) or indirect (thrombotic) mechanisms. Liver is the most commonly involved organ, followed by intestines, oesophagus, stomach, pancreas and spleen. This review describes possible digestive system manifestations in APS patients, and illustrates the epidemiology and possible pathophysiology of APS. The role of different treatment strategies in the management of digestive system manifestations of APS were also discussed.Key messagesAntiphospholipid syndrome is a multi-organ, multi-system disease and its clinical manifestation spectrum is gradually expanding. Since the first diagnosis of APS, the clinical manifestations of digestive system have been reported successively. This narrative review describes the major digestive system manifestations of APS and illustrates the epidemiology, pathophysiology and the role of therapeutic strategies of these patients.

Gastrointestinal symptoms as the first manifestation of antiphospholipid syndrome

Background

Antiphospholipid syndrome (APS) is an acquired pre-thrombotic autoimmune condition, which produces autoantibodies called antiphospholipid antibodies (APL) against phospholipid-binding plasma proteins. The diagnosis of APS requires at least one of Sapporo standard clinical manifestations and one laboratory criteria (persistently medium/high titer anticardiolipin antibodies, and/or medium/high titer anti-β2-glycoprotein I antibodies, and/or a positive lupus anticoagulant test). Gastrointestinal lesions are rarely reported in APS patients. APS cases with recurrent abdominal pain as the first clinical manifestation are even rarer.

Case presentation

This report describes an APS case with recurrent abdominal pain as the first clinical manifestation of antiphospholipid syndrome. The patient has a history of two miscarriages. Computed tomography of the abdomen confirmed mesenteric thrombosis and intestinal obstruction while laboratory tests for serum antiphospholipid and anti-β2-glycoprotein I antibodies were positive. This led to the diagnosis of APS.

Conclusions

This paper provides useful information on gastrointestinal manifestations and APS, also including a brief literature review about possible gastrointestinal symptoms of APS.

Spinal and cerebral hematoma in systemic lupus erythematosus and antiphospholipid syndrome: is drug interaction the culprit?

OBJECTIVES

Thrombotic events are common in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). Warfarin is the most commonly used anticoagulant drug for thrombosis treatment, but it is can interact with many drugs, foods, or medicinal herbs. Herein, we presented a case with SLE and APS who was complicated by spinal and cerebral hematoma as a result of warfarin interaction.

CASE PRESENTATION

Spinal subdural hematoma and frontal intraparenchymal hematoma were occurred in our patient, who was in remission for 2 years with rituximab, hydroxychloroquine and warfarin. We learned that she had been using some herbal products (shepherd's purse and horsetail) and phenyramidol for a few days. Spinal and cerebral hematomas caused by the interaction of phenyramidol and warfarin were treated with fresh frozen plasma and vitamin K without the need for surgery.

CONCLUSIONS

The drug interactions with warfarin can cause fatal hemorrhagic or thrombotic events. Especially, the patients with SLE and/or APS using warfarin should be warned not to use different medications or herbal agents.

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).

[Rare causes of stroke-a frequent stroke etiology]

As a whole, rare stroke causes represent a frequent stroke etiology. Since rare stroke causes affect primarily young patients, early diagnosis and treatment are of high socioeconomic relevance. In our everyday clinical practice, cervical artery dissection, which is the most common stroke etiology among patients < 45 years, and vasculitis are particularly important. In the case of vasculitis, devastating disease courses and potentially harmful treatment options complicate clinical decision-making. Non-vasculitic vasculopathies, infections, hematological disorders, coagulation disorders, metabolic disorders and malignancies are further rare causes of stroke with variable clinical manifestations, thus impeding an early diagnosis. If eligible, patients with rare stroke causes should be considered for thrombectomy. Except for infective endocarditis, most rare stroke causes are not per se a contraindication to thrombolysis, so that eligible patients should also be considered for thrombolysis. Evidence based recommendations for the secondary prevention of most rare stroke causes are still missing. In many cases, treatment regimens are adapted to the patients' individual risk of stroke recurrence and bleeding complications.

Influence of andrographolide on the pharmacokinetics of warfarin in rats

CONTEXT

Andrographolide and warfarin are often used together in clinics in China. However, the herb-drug interaction between andrographolide and warfarin is still unknown.

OBJECTIVE

This study investigates the herb-drug interaction between andrographolide and warfarin in vivo and in vitro.

MATERIALS AND METHODS

A sensitive and reliable LC-MS/MS method was developed for the determination of warfarin in male Sprague-Dawley rats plasma, and then the pharmacokinetics of orally administered warfarin (0.5 mg/kg) with or without andrographolide (30 mg/kg/day for 7 days) pretreatment was investigated. In addition, Sprague-Dawley rat liver microsomes incubation systems were used to support the in vivo pharmacokinetic data and investigate its potential mechanism.

RESULTS

The method validation results showed that a sensitive and reliable LC-MS/MS method was developed for the determination of warfarin in rat plasma samples. The pharmacokinetic results indicated that co-administration of andrographolide could increase the systemic exposure of warfarin significantly, including area under the curve (118.92 ± 18.08 vs. 60.58 ± 9.46 μg × h/mL), maximum plasma concentration (3.32 ± 0.41 vs. 2.35 ± 0.25 μg/mL) and t_1/2 (22.73 ± 3.28 vs. 14.27 ± 2.67 h). Additionally, the metabolic stability of warfarin increased from 23.5 ± 4.7 to 38.7 ± 6.1 min with the pretreatment of andrographolide, and the difference was significant (p < 0.05).

DISCUSSION AND CONCLUSION

In conclusion, andrographolide could increase the systemic exposure of warfarin in rats when andrographolide and warfarin were co-administered, and possibly by slowing down the metabolism of warfarin in rat liver by inhibiting the activity of CYP3A4 or CYP2C9.

Anticoagulating patients with high-risk acquired thrombophilias

Antiphospholipid syndrome (APS), heparin-induced thrombocytopenia, and paroxysmal nocturnal hemoglobinuria are 3 acquired thrombophilias that carry a high risk of venous and arterial thromboembolism. Management of these conditions has largely included anticoagulation with a vitamin K antagonist after an initial period of a parenteral anticoagulant, for as long as the thrombotic risk is still present. The available evidence for the use of direct oral anticoagulants (DOACs) is limited and primarily consists of case series and cohort studies, which are summarized in this chapter. Randomized trials evaluating DOACs in patients with APS are reviewed. Further research is needed prior to widely adopting DOACs for use in these high-risk acquired thrombophilias; however, there may be selected low-risk subgroups where DOAC use is possible after careful consideration and patient discussion.

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.

Perioperative Management of Patients with Inflammatory Rheumatic Diseases Undergoing Major Orthopaedic Surgery: A Practical Overview

Patients with inflammatory rheumatic diseases often need orthopaedic surgery due to joint involvement. Total hip replacement and total knee replacement are frequent surgical procedures in these patients. Due to the complexity of the inflammatory rheumatic diseases, the perioperative management of these patients must envisage a multidisciplinary approach. The frequent association with extraarticular comorbidities must be considered when evaluating perioperative risk of the patient and should guide the clinician in the decision-making process. However, guidelines of different medical societies may vary and are sometimes contradictory. Orthopaedics should collaborate with rheumatologists, anaesthesiologists and, when needed, cardiologists and haematologists with the common aim of minimising perioperative risk in patients with inflammatory rheumatic diseases. The aim of this review is to provide the reader with simple practical recommendations regarding perioperative management of drugs such as disease-modifying anti-rheumatic drugs, corticosteroids, non-steroidal anti-inflammatory drugs and tools for a risk stratification for cardiovascular and thromboembolic risk based on current evidence for patients with inflammatory rheumatic diseases.

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 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 or anticoagulant agents, or both, for the secondary prevention of recurrent thrombosis, particularly ischemic stroke, in people with antiphospholipid syndrome.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (February 2017), CENTRAL (last search February 2017), MEDLINE (from 1948 to February 2017), Embase (from 1980 to February 2017), and several ongoing trials registers. We also checked the reference lists of included studies, systematic reviews, and practice guidelines, and we contacted experts in the field.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated any anticoagulant or antiplatelet agent, or both, in the secondary prevention of thrombosis in people diagnosed 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 selected studies for inclusion, extracted data, and assessed the risk of bias for the included studies. We resolved any discrepancies through discussion or by consulting a third review author and, in addition, one review author checked all the extracted data.

MAIN RESULTS

We included five studies involving 419 randomized participants with APS. Only one study was at low risk of bias in all domains. One study was at low risk of bias in all domains for objective outcomes but not for quality of life (measured using the EQ-5D-5L questionnaire). We judged the other three studies to be at unclear or high risk of bias in three or more domains.The duration of intervention ranged from 180 days to a mean of 3.9 years. One study compared rivaroxaban (a novel oral anticoagulant: NOAC) with standard warfarin treatment and reported no thrombotic or major bleeding events, but it was not powered to detect such differences (low-quality evidence). Investigators reported similar rates of clinically relevant non-major bleeding (risk ratio (RR) 1.45, 95% confidence interval (CI) 0.25 to 8.33; moderate-quality evidence) and minor bleeding (RR 1.21, 95% CI 0.51 to 2.83) for participants receiving rivaroxaban and the standard vitamin K antagonists (VKA). This study also reported some small benefit with rivaroxaban over the standard VKA treatment in terms of quality of life health state measured at 180 days with the EQ-5D-5L 100 mm visual analogue scale (mean difference (MD) 7 mm, 95% CI 2.01 to 11.99; low-quality evidence) but not measured as health utility (MD 0.04, 95% CI -0.02 to 0.10 [on a scale from 0 to 1]).Two studies compared high dose VKA (warfarin) with moderate/standard intensity VKA and found no differences in the rates of any thrombotic events (RR 2.22, 95% CI 0.79 to 6.23) or major bleeding (RR 0.74, 95% CI 0.24 to 2.25) between the groups (low-quality evidence). Minor bleeding analyzed using the RR and any bleeding using the hazard ratio (HR) were more frequent in participants receiving high-intensity warfarin treatment compared to the standard-intensity therapy (RR 2.55, 95% CI 1.07 to 6.07; and HR 2.03, 95% CI 1.12 to 3.68; low-quality evidence).In one study, it was not possible to estimate the RR for stroke with a combination of VKA plus antiplatelet agent compared to a single antiplatelet agent, while for major bleeding, a single event occurred in the single antiplatelet agent group. In one study, comparing combined VKA plus antiplatelet agent with dual antiplatelet therapy, the RR of the risk of stroke over three years of observation was 5.00 (95% CI 0.26 to 98.0). In a single small study, the RR for stroke during one year of observation with a dual antiplatelet therapy compared to single antiplatelet drug was 0.14 (95% CI 0.01 to 2.60).

AUTHORS' CONCLUSIONS

There is not enough evidence for or against NOACs or for high-intensity VKA compared to the standard VKA therapy in the secondary prevention of thrombosis in people with APS. There is some evidence of harm for high-intensity VKA regarding minor and any bleeding. The evidence was also not sufficient to show benefit or harm for VKA plus antiplatelet agent or dual antiplatelet therapy compared to a single antiplatelet drug. Future studies should be adequately powered, with proper adherence to treatment, in order to evaluate the effects of anticoagulants, antiplatelets, or both, for secondary thrombosis prevention in APS. We have identified five ongoing trials mainly using NOACs in APS, so increasing experimental efforts are likely to yield additional evidence of clinical relevance in the near future.