The next step is to consider stroke prevention (ie, oral anticoagulation therapy) for patients with 1 or more non-sex CHA2DS2-VASc stroke risk factors. For patients with a single non-sex CHA2DS2-VASc stroke risk factor, we suggest oral anticoagulation rather than no therapy, aspirin,orcombinationtherapywithaspirinandclopidogrel;andforthoseathighriskofstroke(eg, CHA2DS2-VASc $ 2 in males or $ 3 in females), we recommend oral anticoagulation rather than notherapy,aspirin,orcombinationtherapywithaspirinandclopidogrel.Wherewerecommendor suggest in favor of oral anticoagulation, we suggest using a non-vitamin K antagonist oral anti- coagulant drug rather than adjusted-dose vitamin K antagonist therapy. With the latter, it is important to aim for good quality anticoagulation control with a time in therapeutic range > 70%. Attention to modi able bleeding risk factors (eg, uncontrolled BP, labile international normalized ratios, concomitant use of aspirin or nonsteroidal antiin ammatory drugs in an anticoagulated patient, alcohol excess) should be made at each patient contact, and HAS-BLED (hypertension, abnormal renal/liver function [1 point each], stroke, bleeding history or predisposition, labile in- ternationalnormalized ratio, elderly (0.65), drugs/alcoholconcomitantly [1 point each]) score used to assess the risk of bleeding where high risk patients ($ 3) should be reviewed and followed up more frequently. CONCLUSIONS: Oral anticoagulation is the optimal choice of antithrombotic therapy for patients with AF with $1 non-sex CHA2DS2-VASc stroke risk factor(s). KEY WORDS: antithrombotic therapy; atrial brillation; evidence-based medicine; guidelines Note on Shaded Text: In this guideline, shaded text with an asterisk (shading appears in PDF le only) refers to recommendations that remain unchanged from the previous version of the guideline. Summary of Recommendations 1. For patients with AF, including those with paroxysmal AF, stroke risk should be assessed using a risk factor based approach, rather than an categorization into low, moderate/high risk strata. 