Atrial fibrillation is the commonest cardiac arrhythmia. While a number of established drug therapies are often successful in achieving satisfactory control, more recently radiofrequency catheter ablation has emerged as an effective therapy for patients with paroxysmal AF.  However, the place of catheter ablation remains unclear with limited data comparing ablation with antiarrhythmic drug therapy as first-line treatment in patients.

In the MANTRA-PAF trial 294 patients (mean age 55) with new onset paroxysmal atrial fibrillation and no history of antiarrhythmic drug use were randomly assigned to an initial strategy of either catheter ablation (146 patients) or therapy with class IC or class III antiarrhythmic agents (148 patients). Follow-up was by 7-day Holter-monitoring at 3, 6, 12, 18, and 24 months. The primary end points were the cumulative and per-visit burden of atrial fibrillation (i.e., percentage of time in atrial fibrillation). During follow-up there was no significant difference between ablation and drug-therapy in cumulative AF burden (90th percentile of arrhythmia burden, 13% and 19%, respectively; P=0.10) or the burden at 3, 6, 12, or 18 months. At 24 months, the burden of atrial fibrillation was significantly lower in the ablation group (90th percentile, 9% vs. 18%; P=0.007), and more patients in the ablation group were free from any AF (85% vs. 71%, P=0.004) and from symptomatic AF (93% vs. 84%, P=0.01). However, this slight improvement came at the price of one death in the ablation group due to a procedure-related stroke and there were also three cases of cardiac tamponade.
Conclusions:

In this study there is no significant difference between catheter ablation and antiarrhythmic drug therapy as first-line treatment in patients with paroxysmal atrial fibrillation. In view of the potential for significant complications with catheter ablation, current practice of using drug therapy as first line treatment appears justified.

• Cosedis Nielsen J, Johannessen A, Raatikainen P, Hindricks G, Walfridsson H, Kongstad O, Pehrson S, Englund A, Hartikainen J, Mortensen LS, Hansen PS. Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation. N Engl J Med. 2012 Oct 25;367(17):1587-95.