These agents also raise important concerns, however, including substantial cost to the healthcare system, renal clearance, short half-lives, general unavailability of a moni- toring test to ensure compliance, and lack of a specific agent to reverse their anticoagulant effects.412 Although a dabigatran dose of 75 mg twice daily was approved for patients with creatinine clearance of 15 to 30 mL/min, such subjects were in fact excluded from RE-LY and have not been extensively studied. The short half-lives of the newer anticoagulants raise the possibility of increased risk of cardioembolism if doses are missed, a concern heightened by the relatively large number of events in ROCKET AF occurring between 2 and 7 days after discontinuation of rivaroxaban.400 In assessments of the lack of reversing agent for the newer anticoagulants, it is important to consider that even warfarin-related ICH mortality rates are extremely high despite the availability of reversing agents.413 An analysis of ICH events occurring on dabigatran 150 mg twice daily and adjusted-dose warfarin in RE-LY found no difference in mortality (35% versus 36%) and, because of the lower overall risk of bleeding with dabigatran, significantly fewer deaths caused by ICH (13 versus 32; P<0.01). In studies of antiplatelet agents for nonvalvular AF, aspirin offers modest protection against stroke (RR reduction, 22%; No convincing data favor 1 dose of aspi- rin (50 325 mg daily) over another. Two randomized trials assessed the potential role of the combination of clopidogrel (75 mg daily) plus aspirin (75 100 mg daily) for prevent- ing stroke in patients with AF. 