Background: Recently a multi-electrode radiofrequency balloon (RFB) for pulmonary vein isolation (PVI) was introduced.

Objectives:  The aim of this single-center study was to investigate the incidence, and prognostic significance of early recurrences of atrial tachyarrythmia (ERAT) following RFB-based PVI.

Methods:  Consecutive patients with symptomatic atrial fibrillation (AF) were enrolled to undergo RFB-PVI. A 3D map guided the RFB navigation. Standard ablation procedures were done according to the recently published AURORA-registry study. All patients treated between December 2020 and March 2022 were enrolled in the study. ERAT was defined as documented AF/atrial tachycardia (AT) lasting more than 30 seconds within a 90-day blanking period (BP). Demographic data were analyzed.

Results: A total of 63 consecutive patients (40% female, age 68±10, 57% paroxysmal atrial fibrillation [PAF]) were included. Median follow-up time was 389 days. Thirty-three of 63 (52%) experienced ERAT after a median of 2 days: Of these patients 58% and 42% had been ablated for PAF and persistent AF (persAF), respectively. The majority of ERAT events (22/33, 67%) occurred within the first week. ERAT patients were treated with antiarrhythmic drugs (58% amiodaron, <0.1% verapamil or betablocker) and/or electrocardioversion (ECV; 64% both, <0.1 only ECV). Of all patients with ERAT, 10/33 (30%) experienced AT/AF recurrence after the end of the blanking period. Similarly, patients without ERAT experienced an AT/AF recurrence out of blanking in 8/30 patients (27%; p=0.33). Focusing on baseline characteristics (type of AF, NYHA, diabetes mellitus, coronary artery disease, LA-diameter, LV-EF, BMI, age, stroke), we could not find any predictor for ERAT. Kaplan Meier estimated freedom of AF/AT out of the BP was 79% at one year, 86% for PAF and 73% for persAF (p<0.03). 

Conclusions:  This study indicates an unexpected high rate of ERAT after RFB-based PVI. ERAT did not seem to have a prognostic relevance. After a median of 389 days, 79% of all patients are free of AF/AT at one year. More studies are needed to better examine the significance of ERAT following RFB-PVI.