We recommend that all patients with AF or AFL (paroxysmal, persistent, or permanent) should be stratified using a predictive index for stroke (eg, CHADS₂) and for the risk of bleeding (eg, HAS-BLED) and that most patients should receive antithrombotic therapy. (Recommendation Strong, Quality High)

We recommend that patients at very low risk of stroke (CHADS₂ = 0) should receive aspirin (75-325 mg/d). (Recommendation Strong, Quality High)

We recommend that patients at low risk of stroke (CHADS₂ = 1) should receive OAC therapy (either warfarin [INR 2 to 3] or Dabigatran.) (Recommendation Strong, Quality High)

We suggest, based on individual risk-benefit considerations, that aspirin is a reasonable alternative for some. (Recommendation Conditional, Quality Moderate)

Values and preferences: This recommendation places relatively greater weight on the absolute reduction of stroke risk with both warfarin and dabigatran compared with aspirin and less weight on the absolute increased risk for major hemorrhage with an OAC compared with aspirin.

We recommend that patients at moderate risk of stroke (CHADS₂ ≥2 should receive OAC therapy (either warfarin [INR 2-3] or Dabigatran.) (Recommendation Strong, Quality High)

We suggest that when OAC therapy is indicated, most patients should receive dabigatran in preference to warfarin. In general, the dose of dabigatran 150 mg by mouth twice a day is preferable to a dose of 110 mg by mouth twice a day (exceptions discussed in text.) (Recommendation Conditional, Quality High)

Values and preferences: This recommendation places a relatively high value on the greater efficacy of dabigatran during a relatively short time of follow-up, particularly among patients who have not previously received an OAC; the lower incidence of intracranial hemorrhage; and its ease of use — and less value on the long safety experience with warfarin.