Summary
Direct oral factor inhibitors (DOFIs) are an attractive alternative to vitamin K antagonists
(VKA) for the treatment of patients with antiphospholipid syndrome (APS). In the absence
of prospective, randomised trial data, reports of therapeutic failures in clinical
practice alert clinicians to potential limitations of DOFI therapy for this indication.
Data for all cases were collected from a centralised system that contains complete
medical records of all patients treated and followed at Mayo Medical Center. We present
here three consecutive APS patients who had had no thromboembolism recurrence on warfarin
but were switched to DOFIs. The diagnosis of APS was established according to currently
recommended criteria. The three cases were as follows: A woman with primary APS developed
thrombotic endocarditis with symptomatic cerebral emboli after transition to dabigatran.
A second woman with primary APS experienced ischemic arterial strokes and right transverse-sigmoid
sinus thrombosis after conversion to rivaroxaban. A man with secondary APS suffered
porto-mesenteric venous thrombosis after switching to rivaroxaban. None of these patients
had failed warfarin prior to the transition to DOFIs. Based on these three cases,
we advocate caution in using DOFIs for APS patients outside of a clinical trial setting,
until further data becomes available.
Keywords
Direct oral anticoagulants - warfarin - antiphospholipid syndrome - thromboembolic
complications