Abstract 16890: Ablation of Atrial Fibrillation Rotors and Focal Sources Improves Outcome Over Conventional Ablation Alone in Independent Laboratories: Multicenter Validation of Focal Impulse and Rotor Modulation (FIRM)
Background: The CONFIRM (CONventional ablation for atrial fibrillation (AF), with or without Focal Impulse and Rotor Modulation [FIRM]) trial showed that ablation of electrical rotors or focal sources for AF greatly increased AF elimination compared to pulmonary vein isolation (PVI) alone. This study tests whether similar results can be achieved by other groups early in their use of FIRM.
Methods: We recruited 189 AF patients (pts; 62±9 YO; 26 women, 150 persistent). AF was recorded by basket catheters and mapped with RhythmViewTM (Topera Inc). FIRM-guided ablation (<10 min/source) was followed by conventional ablation (CONV) in 114 pts (76% persistent AF; LA 54±9 mm): 51 in San Diego (index site) and 63 at 11 new sites (median 7.5 pts/site). CONV (PVI, + roof line in persistent AF) was performed in 75 pts at the index site (68% persistent AF; LA 45±7 mm; p<0.01). Recurrent AF was detected with quarterly event/Holter monitors or implanted monitors (29%).
Results: Compared to the index site, pts at new sites had similar age and proportion of persistent AF pts, but more women and larger left atria (LA, p<0.05). Stable AF rotors/focal drivers were seen in 98.4% (186/189) of pts, for 2.3±1.4 sources each (fig A; 69.6% LA, 30.4% RA). Total FIRM ablation time (13.7±9.2 min) was similar at new vs index sites for the acute endpoint of AF termination/non-inducibility or 10% slowing of AF rate (84.2% vs 81.1%; p=0.65). On followup (fig B), single-procedure AF-freedom was 75.4% (FIRM-guided) vs 41.6% (CONV) for 227 days (median, IQR 127-470; p<0.005). For first-ablation pts at new sites only (fig C), single procedure AF-freedom was 80.1% for FIRM-guided ablation (p=0.02 vs CONV).
Conclusions: This multicenter study shows that elimination of AF rotors or focal sources yields results similar to the CONFIRM trial index site with substantially improved single-procedure success of AF ablation, validating results from the CONFIRM trial, and show that the learning curve for FIRM-ablation can be rapid.
- © 2013 by American Heart Association, Inc.