Written by Peter Liu
Spoon Feed
In patients with thrombotic antiphospholipid syndrome (APS), warfarin is generally superior to direct oral anticoagulant (DOAC) therapy for secondary thrombosis prevention.
When it comes to DOACs, DON’T write them in antiphospholipid syndrome
For most conditions that warrant anticoagulation therapy, including atrial fibrillation and venous thromboembolism, DOACs have become the first-line oral medication over warfarin, due to mounting evidence of lower bleeding risk, similar or better efficacy, and lower lab monitoring burden. However, a large body of evidence, including today’s RCT, maintains antiphospholipid syndrome as a clear exception.
This randomized, open-label, multicenter, noninferiority trial assessed rivaroxaban versus warfarin for preventing thromboembolic events in high-risk patients with triple-positive (lupus anticoagulant, anti-ß2-glycoprotein, and anticardiolipin antibody positive) antiphospholipid syndrome (APS). After enrolling 120 patients, the study was terminated early due to excess thromboembolic, bleeding, and vascular mortality events in the rivaroxaban group (19% vs. 3% with warfarin, HR 6.7, 95%CI 1.5-30.5, p=0.01). Stroke and myocardial infarction occurred in 12% of rivaroxaban users versus none with warfarin, highlighting rivaroxaban’s inferiority for APS management in triple-positive APS.
These findings, combined with similar results from apixaban trials in APS, provide high-quality evidence that warfarin is generally superior to DOAC therapy for patients with APS.
How does this change my practice?
There are now only a few domains where warfarin is generally superior to DOACs: mechanical heart valves, rheumatic atrial fibrillation, and thrombotic antiphospholipid syndrome. As a result, it takes extra diligence to consider these exceptions, and to prescribe the appropriate AC therapy (usually warfarin) when these cases arise.
Source
Rivaroxaban vs warfarin in high-risk patients with antiphospholipid syndrome. Blood. 2018 Sep 27;132(13):1365-1371. doi: 10.1182/blood-2018-04-848333. Epub 2018 Jul 12. PMID: 30002145
