Apixaban for treatment of embolic stroke of undetermined source (ATTICUS randomized trial): Rationale and study design:

RationaleOptimal secondary prevention of embolic stroke of undetermined source is not established. The current standard in these patients is acetylsalicylic acid, despite high prevalence of yet undetected paroxysmal atrial fibrillation.AimThe ATTICUS randomized trial is designed to determine whether the factor Xa inhibitor apixaban administered within 7 days after embolic stroke of undetermined source, is superior to acetylsalicylic acid for prevention of new ischemic lesions documented by brain magnetic resonance imaging within 12 months after index stroke.DesignProspective, randomized, blinded, parallel-group, open-label, German multicenter phase III trial in approximately 500 patients with embolic stroke of undetermined source. A key inclusion criterion is the presence or the planned implantation of an insertable cardiac monitor. Patients are 1:1 randomized to apixaban or acetylsalicylic acid and treated for a 12-month period. It is an event-driven trial aiming for core-lab adjudicated primary outcome ...