Some light in the shadows of atrial fibrillation and stroke

In ischemic stroke, the diagnostic workup determines the best preventive strategy. However, cryptogenic stroke accounts for about 20%–40% of all strokes.1 For these patients, the best preventive treatment remains unknown, and most guidelines recommend risk factor modification and antiplatelet therapy. Given the substantial recurrence rate for cryptogenic stroke, this is not a comfortable situation: just try to tell your stroke patients, “After all these tests, I do not have any clue why you had a stroke”; and about the treatment, “Just take an aspirin and cross fingers you do not have another one.”