Atrial fibrillation is initiated by focal triggers and maintained by an atrial substrate called fractioned complex of atrial electrograms. Isolating the pulmonary veins (triggers) through a circumferential ablation is the choice treatment in refractory atrial fibrillation but with suboptimal results.

This work tested the hypothesis that don’t only isolate the pulmonary veins but also the atrial substrate complexes (fractioned) in an attempt to reduce the recurrence of the arrhythmia. The study used the navigation system Ensite NavX v8. 0 (St Jude Medical) for the ablation of fractioned complexes compared to only isolate the pulmonary veins in patients with symptomatic refractory atrial fibrillation to medical treatment. The primary endpoint was survival free of atrial fibrillation at 6 months without the use of anti-arrhythmic medication. In patients with paroxysmal AF ablation of fractioned complexes did not reach statistical significance for noninferiority compared with pulmonary vein isolation. To those with persistent AF, ablation of fractioned complexes and pulmonary veins was not superior when only isolate the pulmonary veins and also a tendency to higher incidence of complications.

Conclusion:

Ablation of fractioned complexes added to the isolation of pulmonary veins improves outcome in patients with paroxysmal or persistent atrial fibrillation.

Felipe Atienza
2013-11-19

Original title: RADAR-AF Trial. A Randomized Multicenter Comparison of Radiofrequency Catheter Ablation of Drivers versus Circumferential Pulmonary Vein Isolation in Patients with Atrial Fibrillation