Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation.

To the Editor: In the study by Cosedis Nielsen et al. (Oct. 25 issue),1 the authors report that there was no significant difference between the use of antiarrhythmic drugs and radiofrequency ablation as primary therapy for paroxysmal atrial fibrillation during a 2-year period. We have concerns regarding this conclusion. The outcomes are clouded by the intention-totreat analysis. Crossover to the alternative therapy (without a ruling of treatment failure) occurred in 36% of patients in the group assigned to receive antiarrhythmic drugs and in 9% of patients assigned to receive radiofrequency ablation. On-treatment analysis would have more accurately reflected the efficacy of therapy. Although the authors report no betweengroup difference in the rates of death or adverse events, they oddly conclude that given the risk of complications with radiofrequency ablation, antiarrhythmic drugs should be considered firstline therapy. The authors emphasize the rate of procedure-related death with radiofrequency ablation, yet they do not highlight the sudden death event in the group receiving antiarrhythmic drugs, which may represent a proarrhythmic death. Without significant differences in adverse events, the data support a patient-specific treatment strategy. If the objective of initial therapy is a reduction in the atrial fibrillation burden, then antiarrhythmic drug therapy is preferred. However, if the objective is freedom from atrial fibrillation, then the study confirms that radiofrequency ablation is superior to antiarrhythmic drug therapy.