Antiarrhythmic drug therapy for six weeks following ablation for atrial fibrillation is well tolerated and reduces the incidence of clinically significant atrial arrhythmias and the need for cardioversion or hospitalization, according to a presentation at Heart Rhythm 2008.

The 5A Study, conducted by researchers at the Hospital of the University of Pennsylvania, prospectively randomized 110 patients with paroxysmal atrial fibrillation who had undergone ablation to receive antiarrhythmic drugs or to not receive planned antiarrhythmic therapy.

"It is common for atrial arrhythmias to follow atrial fibrillation ablation early on and antiarrhythmic drugs are often prescribed during this period to reduce arrhythmia episodes, however, the benefit of this approach is unclear," stated Jean-Francois Roux, MD, lead author and electrophysiology fellow at the Hospital of the University of Pennsylvania in Philadelphia, PA.

"Our study was designed to look at the differences in outcome between using empiric antiarrhythmic drug treatment versus not using antiarrhythmic drug treatment in patients with atrial fibrillation who had undergone ablation to determine if there are in fact benefits."

In the treatment group, the agent was given to patients beginning the night of the procedure. In the control group, only atrioventricular nodal blocking agents were prescribed. All patients wore a monitor with daily and symptomatic transmissions for four weeks after discharge and were evaluated at six weeks.

During the six weeks following ablation, 40 percent of patients in the control group met the primary endpoint, a composite of atrial arrhythmias lasting more than 24 hours, requiring hospitalization or cardioversion, or intolerance to antiarrhythmic drug therapy, compared with 14 percent in the treatment group. Three adverse events requiring drug termination involved rash, headaches and severe fatigue.