Antivitamin K drugs in stroke prevention.

Among the different subtypes of ischaemic strokes, almost 20 % are of cardiac origin. Different are the causes of cardioembolic stroke, but the most common is the atrial fibrillation, a supraventricular arrhythmia. Appropriate use of antiplatelet drugs and anticoagulants after transient ischaemic attack (TIA) or ischaemic stroke depends on whether the underlying cause is cardioembolic or of presumed arterial origin. Adequate antiplatelet therapy is recommended for secondary prevention after cerebral ischaemia of presumed arterial origin, whether for patients with TIA and ischaemic stroke of cardiac origin, mainly due to atrial fibrillation. Vitamin K antagonists (VKAs) are highly effective in preventing recurrent ischaemic stroke but have important limitations and are thus underused. Current guidelines still regard Vitamin K Antagonists at INR 2·0-3·0 to be the standard treatment after cerebral ischaemia of cardiac origin for patients who can tolerate them. In this setting antiplatelet therapy provides an alternative when oral anticoagulation is contraindicated or when patient choice or compliance limits choice of therapy, but is much less effective than VKAs. Recent trial data performed with new anticogulants such as the factor Xa and thrombin inhibitors will need to be taken into account, in order to prevent several of the clinical problems actually related to VKAs use.