Anticoagulant choice in antiphospholipid syndrome–associated thrombosis
Background: DOACs have largely replaced VKAs as first-line therapy for venous thromboembolism in patients with adequate renal function. However, there is concern in APS that DOACs may have higher rates of recurrent thrombosis than VKAs when treating thromboembolism.
Dr. David Portnoy
Study design: Randomized noninferiority trial.
Setting: Six teaching hospitals in Spain.
Synopsis: Of adults with thrombotic APS, 190 were randomized to receive rivaroxaban or warfarin. Primary outcomes were thrombotic events and major bleeding. Follow-up after 3 years demonstrated new thromboses in 11 patients (11.6%) in the DOAC group and 6 patients (6.3%) in the VKA group (P = .29). Major bleeding occurred in six patients (6.3%) in the DOAC group and seven patients (7.4%) in the VKA group (P = .77). By contrast, stroke occurred in nine patients in the DOAC group while the VKA group had zero events, yielding a significant relative RR of 19.00 (95% CI, 1.12-321.90) for the DOAC group.
The DOAC arm was not proven to be noninferior with respect to the primary outcome of thrombotic events. The higher risk of stroke in this group suggests the need for caution in using DOACs in this population.
Bottom line: DOACs have a higher risk of stroke than VKAs in patients with APS without a significant difference in rate of a major bleed.
Citation: Ordi-Ros J et. al. Rivaroxaban versus vitamin K antagonist in antiphospholipid syndrome. Ann Intern Med. 2019;171(10):685-94. doi: 10.7326/M19-0291.
Dr. Portnoy is a hospitalist in the Division of Hospital Medicine, Mount Sinai Health System, New York.
