Utility of slow conduction velocity area guided ablation in patients with persistent atrial fibrillation

Pulmonary vein isolation (PVI) is a well-established treatment for atrial fibrillation (AF). However, in patients with persistent AF, PVI alone is often insufficient, and no adjunctive strategy with proven efficacy beyond PVI has been established. Recently, increasing attention has been directed toward local atrial conduction velocity (CV). Slow conduction velocity areas (SCVAs) have been regarded as potential arrhythmogenic substrates, and ablation strategies targeting SCVAs are under investigation. This study evaluated the efficacy of SCVA-guided ablation in patients with persistent AF.

We enrolled 175 patients with persistent AF who underwent initial radiofrequency catheter ablation (RFCA). SCVAs were defined as contiguous atrial regions with a local CV < 0.7 m/s and a surface area ≥ 2.0 cm². SCVA-guided ablation was performed in 84 patients, whereas standard anatomical PVI was performed in 91 patients. The primary outcome was recurrence of AF or occurrence of new-onset supraventricular tachycardia during a two-year follow-up period.

During follow-up, clinical recurrence occurred in 63 patients (36.0%). Patients in the SCVA-guided ablation group demonstrated a significantly higher recurrence-free survival rate compared with those in the standard PVI group (72.6% vs. 56.1%; log-rank P = 0.01). Multivariate analysis identified SCVA-guided ablation (hazard ratio [HR] 0.31, 95% confidence interval [CI] 0.21-0.67, P = 0.003) and left atrial (LA) volume index (HR 1.03, 95% CI 1.01-1.06, P = 0.001) as independent predictors of AF recurrence.

SCVAs represent important arrhythmogenic substrates. Incorporating these regions into PVI significantly reduced AF recurrence compared with standard anatomical PVI.