Multicenter FIRM Registry1
Reproducing the Results of the CONFIRM trial2
The results of the CONFIRM Trial were reproduced in an independent, multi-center study and included 10 centers in the United States.
The success of pulmonary vein isolation (PVI) for atrial fibrillation (AF or Afib) may be improved if stable AF sources identified by mapping the Focal Impulse and Rotor Modulation (FIRM) are also eliminated. The long-term results of this approach are unclear outside the centers where FIRM was developed; thus, the authors assessed outcomes of FIRM-guided AF ablation in the first cases at 10 experienced centers.
Patients included paroxysmal AF, persistent AF and longstanding persistent AF. The only exclusion criterion was an inability or refusal to provide written informed consent. The authors prospectively enrolled (n = 78) consecutive patients (61 ± 10 years) undergoing FIRM-guided ablation for Afib for persistent (n = 48), longstanding persistent (n = 7) or paroxysmal (n = 23) AF. AF recordings from both atria with a 64-pole basket catheter were analyzed using RhythmView®, a novel mapping system designed by Topera Medical, now Abbott Electrophysiology. Identified rotors/focal sources were ablated, followed by PVI.
- 78 consecutive patients
- AF sources detected in 100% of patients
- 25.3% right atrial sources
- Non-randomized registry study
- Further validation that rotors are a sustaining mechanism of AF
In this multicenter learning curve experience of FIRM mapping, mapping and elimination of patient-specific rotors and focal sources with trigger isolation provided >80% single procedure AF elimination in patients predominantly with persistent AF. These acute and chronic results were similar to those originally reported from FIRM by the originating group. FIRM-guided ablation for AF and other complex arrhythmias has a rapid learning curve at experienced ablation centers.
- Miller JM, Kowal RC, Swarup V, et al. Initial Independent Outcomes from Focal Impulse and Rotor Modulation Ablation for Atrial Fibrillation: Multicenter FIRM Registry. J Cardiovasc Electrophysiol. 2014; 25(9):921-929.
- Narayan SM, Krummen DE, Shivkumar K, Clopton P, Rappel W-J, and Miller JM. Treatment of Atrial Fibrillation by the Ablation of Localized Sources-CONFIRM (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation) Trial. J Am Coll Cardiol 2012; 60(7):628-3