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

The CHEST Antithrombotic Therapy for Venous Thromboembolism Disease evidencebased guidelines are now updated in a more frequent, focused manner. Guidance statements from the most recent full guideline and two subsequent updates have not been gathered into a single source. METHODS An international panel of experts with experience in prior Antithrombotic Therapy guideline development reviewed the 2012 CHEST Antithrombotic Therapy guideline and its two subsequent updates. All guideline statements, and their associated Patient, Intervention, Comparator, Outcome questions were assembled. A modified Delphi process was used to select statements considered relevant to current clinical care. The panel further endorsed minor phrasing changes to match the standard language for guidance statements using the modified GRADE format endorsed by the CHEST Guidelines Oversight Committee. The panel appended comments following statements as deemed relevant, including suggesting which statements be updated in future guidelines due to interval evidence. RESULTS We include 58 guidance statements from prior versions of the antithrombotic therapy guidelines, with updated phrasing as needed to adhere to contemporary nomenclature. Statements are classified as strong or weak recommendations based on high, moderate, and low-certainty evidence, using GRADE methodology. The panel suggests that 5 statements are no longer relevant to current practice. CONCLUSION As CHEST continues to update guidance statements relevant to antithrombotic therapy for VTE disease, this manuscript serves as a unified collection of currently relevant statements from the preceding three guidelines. Suggestions are made to update specific statements in future publications.

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