The Extent of Left Atrial Low-Voltage Areas Included in Pulmonary Vein Isolation Is Associated With Freedom from Recurrent Atrial Arrhythmia

Background: The extent of left atrial (LA) baseline low-voltage areas (LVA-B), which may be a surrogate for fibrosis, is associated with recurrent atrial fibrillation (AF) after ablation. This study aimed to assess the relationship between the extent of LVA-B isolated by ablation (LVA-I) and AF recurrence.

Methods: The study cohort included 159 consecutive patients with drug-refractory AF who underwent an initial AF ablation with LA voltage mapping during sinus rhythm. The extent of LVA-B was quantified while excluding the pulmonary veins, LA appendage, and mitral valve area. LVA-I was quantified as the percentage of LVA-B encircled by pulmonary vein isolation. Surveillance and symptom-prompted electrocardiograms, Holter monitors, and event monitors were used to document atrial arrhythmia recurrence for a median follow-up of 712 days (1.95 years).

Results: Of 159 patients, 72% were men and 27% had persistent AF. The mean number of sampled bipolar voltage points was 119 ± 56. The mean LA surface area was 102.3 ± 37.3 cm², and the mean LVA-B was 1.9 ± 3.8 cm². The mean LVA-I was 51.05% ± 36.8% of LVA-B. In the multivariable Cox proportional hazards model adjusted for LA volume, CHA₂DS₂-VASc (Congestive Heart Failure, Hypertension, Age [≥ 75 years], Diabetes, Stroke/Transient Ischemic Attack, Vascular Disease, Age [65-74 years], Sex [Female] score), LVA-B, and AF type, LVA-I was inversely associated with recurrent atrial arrhythmia after the blanking period (hazard ratio, 0.42/percent LVA isolated; P = 0.037).

Conclusions: The extent of LVA-I is independently associated with freedom from atrial arrhythmias after AF ablation, supporting ongoing efforts to target low LA voltage areas and other fibrosis indicators to improve ablation outcomes.