Warfarin Superior to Xarelto in Antiphospholipid Syndrome Save

A 3 year, multicenter, European study shows that rivaroxaban was inferior to warfarin in preventing thrombosis, risk of bleeding similar in patients with the antiphospholipid syndrome (APS) according to the Annals of Internal Medicine. Thus despite the inconvenience of monitoring INR with warfarin, it is still best option for patients with APS. 

This study from Spain included 190 adults with a history of thrombotic APS. APS included those with arterial thrombosis, livedo racemosa, or APS-related cardiac valvular disease.

Patients were randomized to receive rivaroxaban (20 mg/d or 15 mg/d, according to renal function) versus dose-adjusted vitamin K antagonists (VKAs; warfarin) (target international normalized ratio, 2.0 to 3.0, or 3.1 to 4.0 in patients with a history of recurrent thrombosis). The primary efficacy outcome was the proportion of patients with new thrombotic events or major bleeding events.

After 3 years, there was more recurrent thrombosis (11 patients -11.6%) in the rivaroxaban group and 6 (6.3%) in the VKA group (RR in the rivaroxaban group, 1.83 [95% CI, 0.71 to 4.76]).

Stroke was more common with rivaroxaban (9 events vs 0 for warfarin) (RR, 19.00 [CI, 1.12 to 321.9]). Major bleeding events were similar (6.3% rivaroxaban vs. 7.4% VKA) (RR, 0.86 [CI, 0.30 to 2.46]).

The risk for recurrent thrombosis with rivaroxaban was higher with a history of previous arterial thrombosis, livedo racemosa, or APS-related cardiac valvular disease.

Rivaroxaban was associated with a non–statistically significant near doubling of the risk for recurrent thrombosis, thereby questioning the role of new oral anticoagulants in antiphospholipid antibody syndrome.