The impact of additional radiofrequency ablation for atrial fibrillation substrates using with ExTRa-Mapping analysis after Cryo-ablation in patients with persistent atrial fibrillation

Abstract

Abstract Background Pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF) is well established. Cryo-ablation for persistent AF has been reported to be safe and effective and comparable to radiofrequency (RF) ablation in long term arrhythmia-free survival, but the outcome is limited. Phase mapping using software of ExTRa-Mapping is a new tool to clarify the real-time imaging of the AF wave dynamics. Purpose We investigated the distribution of rotors of left atrium (LA) after PVI by Cryo-ablation, and the efficacy and safety of additional RF ablation for AF substrates (rotor modification) after Cryo-ablation. Methods A total of 50 patients who underwent persistent AF ablation in our hospital were enrolled. The Cryo-ablation alone group (Cryo group; n=25) and the Cryo-ablation + additional RF substrates ablation group (Cryo+RF group; n=25) were randomly divided. First, PVI with Cryo-ablation was performed. Second, if AF did not term after PVI, the rotor of LA were analyzed using the NAVX and ExTRa-Mapping system. In Cryo+RF group, the extensive RF ablation of the PV antrum to modify the rotor area were performed (Abstract Picture 1). The recurrence rate of any atrial tachy-arrhythmia without anti-arrhythmic drugs and safety were evaluated in both groups. Results The patient characteristics (69 ± 9.2 years old, body-mass index 24 ± 3.2 kg/m2, LA diameter 43 ± 5.1 mm, left ventricular ejection fraction 60 ± 7.8 %, persistent AF duration 4.2 ± 5.1 months) did not differ between the both groups. The distribution of rotors of LA were predominantly present in the anterior (n = 36) and inferior (n = 27) walls of the LA, with only a few in the posterior wall (n = 7) in the both groups. In Cryo+RF group, except for 4 cases in which AF was termed by PVI or a rotor was not detected, extensive RF modification in anterior antrum of right pulmonary vein was performed in 18 of 21 cases. In an average follow-up of 482 ± 273 days, the recurrence rate of any atrial tachy-arrhythmia was significantly lower in Cryo+RF group compared with Cryo group (p=0.029, Abstract Picture 2). No serious complications occurred in both groups. Conclusion Additional extensive RF ablation of the PV antrum to modify the Rotor area resulted in a lower recurrence rate in patients with persistent AF.Modify the rotor areaRecurrence rate