Using a Medicare-based retrospective cohort study, the stroke risk in patie
nts with atrial flutter (RR = 1.41) was determined to be greater than that
in a control group (RR = 1.00) but less than that in an atrial fibrillation
group (RR = 1.64). Furthermore, patients with atrial flutter who subsequen
tly had an episode of atrial fibrillation had a higher risk of stroke (RR =
1.56) than patients with atrial flutter who never had a subsequent episode
of atrial fibrillation (RR = 1.11).