Anticoagulating patients with high-risk acquired thrombophilias

Challenges in Treating Extensive Deep Vein Thrombosis with Severe Thrombocytopenia in Patients with Antiphospholipid Syndrome-A Follow-up of 2 Years

Thrombocytopenia is one of the most common manifestations of antiphospholipid syndrome (APS). There is little evidence or definitive guidelines regarding the treatment of APS with thrombocytopenia. We describe a patient with APS and moderate-to-severe thrombocytopenia and the challenges of balancing anticoagulation with thrombocytopenia. A 19-year-old male patient presented with right lower limb swelling to the emergency department with a history of gradually worsening right leg swelling for 1 week and was diagnosed with right leg proximal deep vein thrombosis. Ultrasound Doppler of the right lower limb revealed complete venous thrombosis from the level of the popliteal vein to the distal superficial femoral vein. Subsequently, he was found to have triple-positive APS and moderate-to-severe immune thrombocytopenia, with a platelet count nadir of 31 × 10 to the ninth power/L. He was started on anticoagulation with warfarin. The severe thrombocytopenia was not treated with immunosuppressants and the platelets fluctuated in the range of moderate-to-severe thrombocytopenia but did not develop any rethrombotic or bleeding events. His platelets varied from 31 × 10 to the ninth power/L to 106 × 10 to the ninth power/L. This case report demonstrates that it may be safe to hold off treatment for thrombocytopenia in APS, even in cases of severe thrombocytopenia. Treatment with immunosuppressants may be instituted only when platelet levels fall below 20 × 10 to the ninth power/L or when there is clinically significant bleeding, as in primary immune thrombocytopenia.

Successful Treatment With the Oral Factor Xa Inhibitor Edoxaban in Heparin-Induced Thrombocytopenia With Thrombosis

Heparin-induced thrombocytopenia with thrombosis (HITT) is a rare immune reaction to the drug heparin that causes increased blood clotting, putting patients at risk for arterial and venous thromboembolism which can have severe consequences. We present a case of HITT successfully treated with the direct oral anticoagulant (DOAC), edoxaban. A 56-year-old man had surgery to remove a colorectal mass. After discharge, he developed chest discomfort, shortness of breath, and low oxygen levels and was diagnosed with a right-sided lobar pulmonary embolism. His platelet count dropped, his tests confirmed a diagnosis of HITT, and he was initially treated with fondaparinux. After showing clinical and laboratory improvement, he was switched to edoxaban. Despite being diagnosed with colonic adenocarcinoma during follow-up, the patient's platelet count returned to normal, and he did not experience any more blood clots or serious bleeding events. The use of DOACs like edoxaban as potential therapies for HITT is promising; further research is being conducted to evaluate their effectiveness, safety, and potential benefits for treating this acquired high-risk thrombophilia.

Swiss Survey on current practices and opinions on clinical constellations triggering the search for PNH clones

This national survey investigated the current practice in Switzerland by collecting participants' opinions on paroxysmal nocturnal hemoglobinuria (PNH) clone assessment and clinical practice.

Aim

This study aimed to investigate clinical indications prompting PNH clones' assessment and physician's accessibility of a flow cytometry facility, and also to understand clinical attitudes on the follow-up (FU) of patients with PNH clones.

Methods

The survey includes 16 multiple-choice questions related to PNH and targets physicians with a definite level of experience in the topic using two screener questions. Opinion on clinical management was collected using hypothetical clinical situations. Each participant had the option of being contacted to further discuss the survey results. This was an online survey, and 264 physicians were contacted through email once a week for 5 weeks from September 2020.

Results

In total, 64 physicians (24.2%) from 23 institutions participated (81.3% hematologists and 67.2% from university hospitals). All had access to flow cytometry for PNH clone testing, with 76.6% having access within their own institution. The main reasons to assess for PNH clones were unexplained thrombosis and/or hemolysis, and/or aplastic anemia (AA). Patients in FU for PNH clones were more likely to be aplastic anemia (AA) and symptomatic PNH. In total, 61% of the participants investigated PNH clones repetitively during FU in AA/myelodysplastic syndromes patients, even when there was no PNH clone found at diagnosis, and 75% of the participants tested at least once a year during FU. Opinions related to clinical management were scattered.

Conclusion

The need to adhere to guidelines for the assessment, interpretation, and reporting of PNH clones emerges as the most important finding, as well as consensus for the management of less well-defined clinical situations. Even though there are several international guidelines, clear information addressing specific topics such as the type of anticoagulant to use and its duration, as well as the indication for treatment with complement inhibitors in some borderline situations are needed. The analysis and the discussion of this survey provide the basis for understanding the unmet needs of PNH clone assessment and clinical practice in Switzerland.

Thrombophilia testing in the era of direct oral anticoagulants

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

Antithrombotic therapy to prevent recurrent pregnancy loss in antiphospholipid syndrome-What is the evidence?

Aspirin and heparin are widely used to reduce the risk of recurrent pregnancy loss in women with antiphospholipid syndrome. This practice is based on only a few intervention studies, and uncertainty regarding benefits and risk remains. In this case-based review, we summarize the available evidence and address the questions that are most important for clinical practice. We performed a systematic review of randomized controlled trials assessing the effect of heparin (low molecular weight heparin [LMWH] or unfractionated heparin [UFH]), aspirin, or both on live birth rates in women with persistent antiphospholipid antibodies and recurrent pregnancy loss. Eleven trials including 1672 women met the inclusion criteria. Aspirin only did not increase live birth rate compared to placebo in one trial of 40 women (risk ratio [RR] 0.94; 95% confidence interval [CI] 0.71-1.25). One trial of 141 women reported a higher live birth rate with LMWH only than with aspirin only (RR 1.20; 95% CI 1.00-1.43). Five trials totaling 1295 women compared heparin plus aspirin with aspirin only. The pooled RR for live birth was 1.27 (95% CI 1.09-1.49) in favor of heparin plus aspirin. There was significant heterogeneity between the subgroups of LMWH and UFH (RR for LWMH plus aspirin versus aspirin 1.20, 95% CI: 1.04-1.38; RR for UFH plus aspirin versus aspirin 1.74, 95% CI: 1.28-2.35; I2  78.9%, p = .03). Characteristics of participants and adverse events were not uniformly reported. Heparin (LMWH or UFH) plus aspirin may improve live birth rates in women with recurrent pregnancy loss and antiphospholipid antibodies, but evidence is of low certainty.

Evaluation and Management of Coagulopathies and Thrombophilias in Pediatric Patients

The diagnosis of coagulopathy or thrombophilia in pediatric patients can be challenging. Congenital coagulopathies often present in the pediatric period and require appropriate work-up for diagnosis and ongoing management. Acquired coagulopathies of childhood are frequently encountered in hospitalized children and warrant appropriate coagulation testing for goal-directed therapy. The incidence of thrombosis is increasing in pediatric patients. After identifying the presence of thrombus, acute management includes initiating therapeutic anticoagulation. Choice of anticoagulant depends on patient's clinical status, along with availability of the anticoagulant. Thrombophilia evaluation is performed when children present with spontaneous thrombosis. Thrombophilia tests are inaccurate during acute illness.

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.

Aspirin or heparin or both for improving pregnancy outcomes in women with persistent antiphospholipid antibodies and recurrent pregnancy loss

BACKGROUND

Aspirin and heparin are widely used as preventive strategy to reduce the high risk of recurrent pregnancy loss in women with antiphospholipid antibodies (aPL). This review supersedes a previous, out-of-date review that evaluated all potential therapies for preventing recurrent pregnancy loss in women with aPL. The current review focusses on a narrower scope because current clinical practice is restricted to using aspirin or heparins, or both for women with aPL in an attempt to reduce pregnancy complications.

OBJECTIVES

To assess the effects of aspirin or heparin, or both for improving pregnancy outcomes in women with persistent (on two separate occasions) aPL, either lupus anticoagulant (LAC), anticardiolipin (aCL) or aβ₂-glycoprotein-I antibodies (aβ₂GPI) or a combination, and recurrent pregnancy loss (two or more, which do not have to be consecutive).

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (3 June 2019), and reference lists of retrieved studies. Where necessary, we attempted to contact trial authors.

SELECTION CRITERIA

Randomised, cluster-randomised and quasi-randomised controlled trials that assess the effects of aspirin, heparin (either low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH]), or a combination of aspirin and heparin compared with no treatment, placebo or another, on pregnancy outcomes in women with persistent aPL and recurrent pregnancy loss were eligible. All treatment regimens were considered.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion criteria and risk of bias. Two review authors independently extracted data and checked them for accuracy and the certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Eleven studies (1672 women) met the inclusion criteria; nine randomised controlled trials and two quasi-RCTs. The studies were conducted in the USA, Canada, UK, China, New Zealand, Iraq and Egypt. One included trial involved 1015 women, all other included trials had considerably lower numbers of participants (i.e. 141 women or fewer). Some studies had high risk of selection and attrition bias, and many did not include sufficient information to judge the risk of reporting bias. Overall, the certainty of evidence is low to very low due to the small numbers of women in the studies and to the risk of bias. The dose and type of heparin and aspirin varied among studies. One study compared aspirin alone with placebo; no studies compared heparin alone with placebo and there were no trials that had a no treatment comparator arm during pregnancy; five studies explored the efficacy of heparin (either UFH or LMWH) combined with aspirin compared with aspirin alone; one trial compared LMWH with aspirin; two trials compared the combination of LMWH plus aspirin with the combination of UFH plus aspirin; two studies evaluated the combination of different doses of heparin combined with aspirin. All trials used aspirin at a low dose. Aspirin versus placebo We are very uncertain if aspirin has any effect on live birth compared to placebo (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.71 to 1.25, 1 trial, 40 women, very low-certainty evidence). We are very uncertain if aspirin has any effect on the risk of pre-eclampsia, pregnancy loss, preterm delivery of a live infant, intrauterine growth restriction or adverse events in the child, compared to placebo. We are very uncertain if aspirin has any effect on adverse events (bleeding) in the mother compared with placebo (RR 1.29, 95% CI 0.60 to 2.77, 1 study, 40 women). The certainty of evidence for these outcomes is very low because of imprecision, due to the low numbers of women involved and the wide 95% CIs, and also because of risk of bias. Venous thromboembolism and arterial thromboembolism were not reported in the included studies. Heparin plus aspirin versus aspirin alone Heparin plus aspirin may increase the number of live births (RR 1.27, 95% CI 1.09 to 1.49, 5 studies, 1295 women, low-certainty evidence). We are uncertain if heparin plus aspirin has any effect on the risk of pre-eclampsia, preterm delivery of a live infant, or intrauterine growth restriction, compared with aspirin alone because of risk of bias and imprecision due to the low numbers of women involved and the wide 95% CIs. We are very uncertain if heparin plus aspirin has any effect on adverse events (bleeding) in the mother compared with aspirin alone (RR 1.65, 95% CI 0.19 to 14.03, 1 study, 31 women). No women in either the heparin plus aspirin group or the aspirin alone group had heparin-induced thrombocytopenia, allergic reactions, or venous or arterial thromboembolism. Similarly, no infants had congenital malformations. Heparin plus aspirin may reduce the risk of pregnancy loss (RR 0.48, 95% CI 0.32 to 0.71, 5 studies, 1295 women, low-certainty evidence). When comparing LMWH plus aspirin versus aspirin alone the pooled RR for live birth was 1.20 (95% CI 1.04 to 1.38, 3 trials, 1155 women). In the comparison of UFH plus aspirin versus aspirin alone, the RR for live birth was 1.74 (95% CI 1.28 to 2.35, 2 trials, 140 women).

AUTHORS' CONCLUSIONS

The combination of heparin (UFH or LMWH) plus aspirin during the course of pregnancy may increase live birth rate in women with persistent aPL when compared with aspirin treatment alone. The observed beneficial effect of heparin was driven by one large study in which LMWH plus aspirin was compared with aspirin alone. Adverse events were frequently not, or not uniformly, reported in the included studies. More research is needed in this area in order to further evaluate potential risks and benefits of this treatment strategy, especially among women with aPL and recurrent pregnancy loss, to gain consensus on the ideal prevention for recurrent pregnancy loss, based on a risk profile.

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.