The risk for stroke in patients given anti-arrhythmic therapy for atrial fibrillation is no lower than the risk associated with rate regulation, according to study results presented at the annual meeting of the American Academy of Neurology.

Strokes occurred in 8.9 percent of patients given anti-arrhythmic therapy and in 7.4 percent of patients treated with rate regulation. All of the 4,060 patients enrolled in the 6-year Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study were treated with warfarin.

David G. Sherman, M.D., who presented the findings from the American study, said "While the trial confirmed that use of warfarin, an anticoagulant, reduces the risk of stroke by almost 70 percent, aggressive efforts to control atrial fibrillation did not seem to have nearly as beneficial an effect."

Sherman and coauthor Robert G. Hart, M.D., served on the study Stroke Events Subcommittee. "When a patient was known or suspected to have a stroke while on the study, we received the information to corroborate it and determine the stroke mechanisms, such as clots causing ischemia or bleeding into the brain." A total of 160 strokes were reported in the patients enrolled in the trial, whose mean age was 69.7 years.

Current therapies to keep patients with atrial fibrillation in normal sinus rhythm are "not all that successful" at improving survival or stroke risk, Sherman said.

The Stroke Events Subcommittee concluded that "in the AFFIRM Study, the presence of atrial fibrillation increased ischemic stroke risk and the use of warfarin reduced stroke risk, regardless of assigned treatment strategy."