NOAC can be also used for secondary prevention of cardioembolic
stroke in patients with stroke recurrence despite
appropriate treatment with warfarin.61,62 Although a detailed
review of the prevention of stroke in patients with specific
etiologies is outside the scope of this article, a few common
conditions can be mentioned. For lack of results from clinical
trials on stroke prevention in patients with PFO, antiplatelet
treatment is considered appropriate for stroke patients with
isolated PFO and percutaneous closure of PFO is not recommended.63
In stroke patients with cervicocephalic arterial dissection,
anticoagulation is not recommended over antiplatelet
therapy.64 Patients with ischemic stroke of unclear etiology
and under 45 years of age must be tested for thrombophilia.
Anticoagulant therapy is normally indicated in the event of
a proven deficiency of antithrombin III, protein C, or protein
S, as well as resistance to activated protein C (factor V
Leiden). ASA may be considered as a preventive treatment in
patients with antiphospholipid antibody positivity after a first
ischemic stroke. Oral anticoagulants for an INR of 2–3 are
recommended for patients who meet the criteria for antiphospholipid
syndrome.65 Migraine with aura is associated with
a six to eight-fold increased risk of stroke in patients under
the age of 45 years, but future stroke occurrence remains
unclear. There is no definite guideline for use of antiplatelet/
antithrombotic therapy in stroke prevention for women with
a history of pregnancy-related stroke.