Long-term clinical outcomes of focal impulse and rotor modulation for treatment of atrial fibrillation: A multicenter experience

Abstract

BACKGROUND New approaches to ablation of atrial fibrillation (AF) include focal impulse and rotor modulation (FIRM). Studies of this technology with short-term follow-up have shown favorable outcomes. OBJECTIVE The purpose of this study was to characterize the long-term results of FIRM ablation in a cohort of patients treated at 2 academic medical centers. METHODS All FIRM-guided ablation procedures (n = 43) at UCLA Medical Center and Virginia Commonwealth University Medical Center performed between January 2012 and October 2013 were included for analysis. During AF, FIRM software constructed phase maps from unipolar atrial electrograms to identify putative AF sources. These sites were targeted for ablation, along with pulmonary vein isolation in 77% of patients. RESULTS AF was paroxysmal in 56%, and 67% had prior AF ablation. All patients had rotors identified (mean 2.6 ± 1.2 per patient, 77% in LA). Prespecified acute procedural end-point was achieved in 47% of patients (n = 20): AF termination in 4, organization in 7, >10% slowing of AF cycle length in 9. Acute complications occurred in 4 patients (9.3%). At 18 ± 7 months of follow-up, 37% were free from documented recurrent AF after a 3-month blanking period; 21% were free from documented atrial tachyarrhythmias and off antiarrhythmic drugs. Multivariate analysis did not reveal any significant predictors of AF recurrence, including pattern of AF, acute procedural success, or prior failed ablation. CONCLUSION Long-term clinical results after FIRM ablation in this cohort of patients showed poor efficacy, different from previously published studies. Randomized studies are needed to evaluate the efficacy and clinical utility of this ablation approach for treating AF.

First-in-Man Analysis of the Relationship Between Electrical Rotors From Noninvasive Panoramic Mapping and Atrial Fibrosis From Magnetic Resonance Imaging in Patients With Persistent Atrial Fibrillation

“…New ablation targets include among others complex fractionated atrial electrograms, additional linear lesions sets, homogenization of atrial fibrosis, modulation of the autonomic nervous system, left atrial appendage isolation, and targeting electric rotors from invasive and noninvasive mapping. The initial results of rotor-guided ablation approaches are heterogeneous, 30,31 and the idea to ablate electric rotors needs further validation. 32 In addition, Akoum et al 29,33 recently reported their interesting ablation approach to target preprocedural fibrosis in patients with PERS.…”

The continuous challenge of AF ablation: From foci to rotational activity

“…This may reflect mapping of the epicardium in these studies, where drivers are less stable on optical maps. 7,34 Third, AF-driver ablation outcomes are disappointing at some centers [41][42][43] (Table 1 summarizes PVI and driver ablation studies). Mapping differences will alter reported AF mechanisms, and Rudy et al…”

“…However, while independent centers continue to report positive results, 11,12,54,55 outcomes are disappointing by some operators [41][42][43] (Table 1). Table 1 details the heterogeneity in outcomes from map-guided AF source ablation across centers.…”

Pearls and Pitfalls in Catheter Ablation of Persistent Atrial Fibrillation

“…18 It is also possible that proarrhythmia develops from small channels or gaps ablation outcome. 51 The Bourdeaux group 52 used an array of 252 body surface electrodes and noncontrast computed tomography scan to obtained accurate biatrial geometry. They found that in the early months of persistent AF it is predominantly maintained by unstable reentry drivers with meandering, and periodic occurrence, also different from Narayan's temporary stable rotors.…”