Compared with the RACE trial discussed in the previous Figure, the AFFIRM trial[60] was much larger, with >2000 patients in the both the rate-control and rhythm-control arms.  There were a total of 157 ischemic strokes, distributed evenly between the rate- and rhythm-control groups, and most of these events occurred after the discontinuation of warfarin or in patients whose serum warfarin INR values were at subtherapeutic levels.  
As a result, one of the most important conclusions that can be drawn from AFFIRM is the use of anticoagulant therapy needs to be initiated and continued, regardless of whether a rate- or rhythm-control strategy is chosen.  In terms of negative outcomes, 44 of the patients in the rate control group in AFib when their stroke occurred, and in the rhythm-control group, 25 patients remained in AFib despite the attempt to maintain sinus rhythm with antiarrhythmic therapy. 

Rothman SA. Am J Med 2013; 126: 00-00.