Introduction
Pulmonary vein isolation (PVI) has evolved into a widely accepted and effective strategy for the treatment of atrial fibrillation (AF), which is recommended by the latest guidelines.1 However, we occasionally experience recurrences of atrial tachyarrhythmias after a successful PVI. Early recurrences of atrial tachyarrhythmias (ERATs) during a 90-day blanking period occur in up to 50% of patients after a PVI.2,3 The pathophysiological mechanisms of ERATs are attributed to acute inflammatory changes due to energy deliveries, delayed effects of ablation due to lesion consolidation, and reconnections of isolated PVs.3-5 ERATs reduce the patients’ quality of life owing to various symptoms. In addition, ERATs predict late recurrences after PVI.2,3,6 Therefore, it is important to reduce the incidence of ERATs, even for short periods of time.
Ablation index (AI) is a novel marker of the lesion quality during radiofrequency catheter ablation (CA) and incorporates power in addition to contact force (CF) and time in a weighted formula.7-9 An AI-guided AF ablation improves the incidence of late atrial tachyarrhythmia recurrences as compared to the conventional contact force (CF) guided ablation.8,10However, little is known whether or not an AI-guided PVI can reduce ERATs.
We hypothesized that an AI-guided PVI, which is a novel technology of radiofrequency CA, could reduce the frequency of ERATs. Hence, this study aimed to clarify the effect of AI-guided PVI on ERATs as compared to the conventional CF-guided PVI.