New approaches for the secondary prevention of cryptogenic stroke using non-vitamin K antagonist oral anticoagulants

Abstract

Non-vitamin K antagonist oral anticoagulants (NOACs) were introduced to prevent systemic embolism in patients with non-valvular atrial fibrillation (AF), and the use of NOACs for secondary prevention of cardioembolic stroke in patients with AF has gradually increased. Recently, NOACs were also approved for the prevention for deep venous thrombosis. Therefore, ischemic stroke patients with paradoxical emboli who have right-to-left shunt (such as patent foramen ovale or pulmonary arteriovenous fistula) and deep venous thrombosis may be treated with NOACs. In addition, a new clinical concept, termed “Embolic Stroke of Undetermined Source” (ESUS), has recently been suggested. ESUS has been proposed as an indication for anticoagulation, because paroxysmal AF is a potential mechanism of stroke in ESUS patients. Some large randomized clinical trials have been initiated to determine whether NOACs are superior to antiplatelets for the prevention of recurrent stroke in patients with ESUS. In this review, we discuss the potential use of NOACs for secondary stroke prevention among ischemic stroke patients without AF, especially in patients with cryptogenic stroke.