The clinical trial NOAH – AFNET 6 conducted by the German Atrial Fibrillation Network (AFNET), Münster, Germany, revealed: In patients with atrial high rate episodes (AHRE), but without ECG-documented atrial fibrillation (AF), oral anticoagulation increases bleeding without reducing strokes. Stroke rate was low in patients with AHRE with and without oral anticoagulation. The results were presented today at the annual congress of the European Society of Cardiology (ESC) in Amsterdam and published in the New England Journal of Medicine (1).