There are other possible reasons for the persistence of thrombotic risk in patients who have risk factors for stroke and who have had AFib but are currently in sinus rhythm – or, put another way, although these patients are in sinus rhythm, their risk for stroke does not return to normal. There could be 

• recurrent asymptomatic AFib; 
• incomplete reverse atrial remodeling, with the resultant flow impairment 
• incomplete remodeling of the endothelium
• negative atrial inotropic effects of the AFib drug used or of an attempted ablative therapy procedure.  

There are also concomitant pro-embolic sources, so physicians should not believe that restoration of sinus rhythm removes the risk for stroke in a patient who has had atrial fibrillation – this is one of many misunderstood concepts in AFib management. 

Reiffel JA. Am J Med 2013; 126: 00-00.