Thrombotic events in patients with antiphospholipid syndrome treated with rivaroxaban: a series of eight cases.

The current treatment for antiphospholipid syndrome (APS) with thrombotic manifestation is long-term anticoagulation. Vitamin K antagonists (VKA) are usually the agents of choice. However, VKA limitations, such as unpredictable anticoagulation effects due to interaction with diet and other drugs, require regular monitoring. This may impact on patients' quality of life. Since the approval of new oral anticoagulants (NOAC) for non-valvular atrial fibrillation and deep vein thrombosis prevention, much has been speculated about its use in APS patients. We report here a series of eight APS patients with failure of thrombotic prevention during rivaroxaban use. All patients had venous thrombosis as the initial manifestation of APS, and two of them also had arterial manifestations. Three patients had triple antibody positivity. Five patients developed arterial events during the treatment with rivaroxaban. Until the results of ongoing trials of rivaroxaban for APS are presented, NOAC should not be recommended to APS patients. Our preliminary experience as well cases previously reported in the literature suggest that there is a high-risk group that is less protected with rivaroxaban, namely those with previous arterial thrombosis or triple positivity. VKA remains to be the mainstay treatment for thrombotic APS.