Results from a randomized clinical trial of 127 patients with symptomatic atrial fibrillation (AF) from around the world show that pulmonary vein isolation (PVI) with radiofrequency ablation is safe and significantly superior to the current first-line therapy approach of antiarrhythmic drugs (AAD), as reported from Heart Rhythm 2012, the Heart Rhythm Society's 33rd Annual Scientific Sessions.

The primary objective of the Radiofrequency Ablation vs. Antiarrhythmic Drugs as First-Line Treatment of Symptomatic Atrial Fibrillation (RAAFT 2) clinical trial is to assess whether catheter-based PVI ablation is superior to AAD as first-line therapy in patients with symptomatic paroxysmal/persistent AF who have not been previously treated with antiarrhythmic drugs. 

Primary efficacy outcomes were measured as time to first reoccurrence of electrocardiographic (ECG)-documented AF, therefore, the higher the percentage of patients that reached AF, the less favorable the outcome.  In the AAD group of patients, 72 percent reached the primary efficacy outcome, as opposed to 55 percent of the PVI ablation group – a nearly 20 percent absolute decrease in time to first AF episode for those that received ablation.

The primary safety outcome was the proportion of patients with an occurrence of a cluster of serious complications.  Twenty percent of the AAD group of patients suffered serious complications versus eight percent in the PVI ablation group.  No deaths were reported in either group. 

"We believe our findings are significant enough to point to a change in how we treat patients who have not yet received treatment for symptomatic AF," said Carlos Morillo, M.D., FHRS, author of the study and professor, Division of Cardiology, Department of Medicine at McMaster University, Ontario.  "The analysis revealed that a higher rate of adverse events occur in patients that begin antiarrhythmic drugs first, which is currently the recommended first-line treatment practice.  Our trial showed that ablation is superior in the real world, and is a more effective and safer course of first-line treatment with less patient complications."

Overall, radiofrequency PVI ablation showed a nearly 50 percent relative risk reduction in extending time to first recurrence of symptomatic and asymptomatic AF, atrial flutter and atrial tachycardia in patients with paroxysmal AF.

Secondary outcomes were also more favorable in the PVI ablation group versus the AAD group.