Low voltage-guided ablation of posterior wall improves 5-year arrhythmia-free survival in persistent atrial fibrillation

Abstract

Introduction: The posterior wall (PW) has been proposed as a standard target for ablation beyond pulmonary vein antral isolation (PVI) in patients with persistent atrial fibrillation (AF). However, studies have shown inconsistent outcomes with the addition of PW ablation. The presence or absence of low voltage on the PW may explain these inconsistencies. We evaluated whether PW ablation based on the presence or absence of low voltage improves long-term arrhythmia-free outcomes.

Methods: We retrospectively reviewed 5-year follow-up in 152 consecutive patients who received either standard ablation (SA) with PVI alone or PVI + PW ablation (PWA) based on physician discretion (n = 77) or voltage-guided ablation (VGA) with PVI and addition of PWA only if low voltage was present on the PW (n = 75).

Results: The two groups were well matched for baseline characteristics. At 5-year follow-up, 64% of patients receiving VGA were atrial tachyarrhythmia (AT)/AF free compared to 34% receiving SA (HR 0.358 p < .005). PWA had similar AF recurrence in SA and VGA groups (0.30 vs. 0.27 p = .96) but higher AT recurrence when comparing SA and VGA groups (0.39 vs. 0.15 p = .03). In multivariate analysis, both VGA and PWA predicted AF arrhythmia-free survival (HR 0.33, p = .001 and HR 0.20, p = .008, respectively). For AT, VGA predicted arrhythmia-free survival (HR 0.22, p = .028), while PWA predicted AT recurrence (HR 4.704, p = .0219).

Conclusion: VGA of the posterior wall ablation beyond PVI in persistent AF significantly improves long-term arrhythmia-free survival when compared with non-voltage-guided ablation. PW ablation without voltage-guidance reduced AF recurrence but at the cost of a higher incidence of AT.

Keywords: catheter ablation; low voltage; persistent atrial fibrillation; posterior wall.

Figure 1

Study Design. Breakdown of 152 consecutive patients with persistent atrial fibrillation presenting for catheter ablation with 77 receiving standard ablation strategy and 75 receiving a voltage‐guided strategy.

Figure 2

(Central illustration): Voltage‐guided ablation effect on AT/AF free survival over 5 years. (A, left): Primary outcome AT/AF free survival in SA and VGA groups showing VGA group with significant improvement in 5‐year AT/AF free survival. (B, right, top): Primary outcome AT/AF free survival in VGA and SA groups further divided into PVI + posterior wall and PVI alone subgroups. (C, right, bottom): AF‐only arrhythmia‐free survival in VGA and SA groups further divided into PVI + posterior wall and PVI alone subgroups. AF, atrial fibrillation; AT, atrial tachyarrhythmia; PVI, pulmonary vein antral isolation; SA, standard ablation; VGA, voltage‐guided ablation.

Figure 3

VGA impact on recurrence phenotype. (A, top): Incidence of arrhythmia recurrence, AT (left) and AF (right), in SA and VGA groups in patients that did not receive posterior wall ablation. (B, bottom): Incidence of arrhythmia recurrence, AT (left) and AF (right), in SA and VGA groups in patients that received posterior wall ablation. AF, atrial fibrillation; AT, atrial tachyarrhythmia; SA, standard ablation; VGA, voltage‐guided ablation.

Figure 4

Posterior wall ablation effect on AT/AF free survival over 5 years. (A, left): Reanalyzed data of the entire cohort showing no significant difference between PVI + posterior wall and PVI alone. (B, right, top): Reanalyzed data of the entire cohort comparing AF recurrence only, showing PVI + posterior wall significantly reduced AF recurrence compared to PVI alone. (C, right, bottom): Reanalyzed data of the entire cohort comparing AT recurrence only, showing no significant difference in AT recurrence between PVI + posterior wall and PVI alone. AF, atrial fibrillation; AT, atrial tachyarrhythmia; PVI, pulmonary vein antral isolation.