Benefit of left atrial roof linear ablation in paroxysmal atrial fibrillation: a prospective, randomized study

Abstract

Background: Isolation of the pulmonary veins (PVs) for the treatment of atrial fibrillation (AF) is often supplemented with linear lesions within the left atrium (LA). However, there are conflicting data on the effects of creating a roof line (RL) joining the superior PVs in paroxysmal atrial fibrillation (PAF).

Methods and results: A cohort of 120 patients with drug-refractory PAF referred for ablation were prospectively randomized into 2 strategies: (1) PV isolation in combination with RL ablation (LA roof ablation [LARA]-1: 59 patients) or (2) PV isolation (LARA-2: 61 patients). Follow-up was performed at 1, 3, and 6 months after the procedure and every 6 months thereafter. After a 3-month blanking period, recurrence was defined as the ocurrence of any atrial tachyarrhythmia lasting ≥30 seconds. PV isolation was achieved in 89% and complete RL block in 81%. RF duration, fluoroscopy, and procedural times were slightly, but not significantly, longer in the LARA-1 group. After 15±10 months, there was no difference in the arrhythmia-free survival after a single AF ablation procedure (LARA-1: 59% vs. LARA-2: 56% at 12 months; log rank P=0.77). The achievement of complete RL block did not influence the results. The incidence of LA macroreentrant tachycardias was 5.1% in the LARA-1 group (n=3) versus 8.2% in the LARA-2 (n=5) (P=ns). Univariate analysis only identified AF duration as a covariate associated with arrhythmia recurrence (hazard ratio, 1.01 [95% confidence interval, 1.002 to 1.012]; P<0.01).

Conclusion: The linear block at the LA roof is not associated with an improved clinical outcome compared with PV isolation alone.

Clinical trial registration url: ClinicalTrials.gov. Unique identifier: NCT01203241.

Keywords: atrial fibrillation; catheter ablationy; roof line.

© 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Figures

Figure 1.

Consort flow chart of the study population. LA indicates left atrium; LAVA, left atrial roof linear ablation; LV, left ventricle.

Figure 2.

Ablation strategy. A, PV isolation with roof linear ablation (LARA‐1). B, PV isolation without roof linear ablation (LARA‐2). AP indicates anteroposterior; LAVA, left atrial roof linear ablation; PA, posteroanterior; PV, pulmonary veins.

Figure 3.

Evaluation of conduction block across the roof during pacing from the LA appendage (LAA). A, Color‐coded 3D activation map showing a caudocranial activation of the posterior wall. B, Electrical activation showing shorter activation times at the lower (1: 72 ms) than at the upper posterior wall (2: 98 ms). LA indicates left atrium.

Figure 4.

Color‐coded 3D activation map during pacing from the LA appendage in a patient undergoing a first ablation procedure for paroxysmal AF. A, Anteroposterior and posteroanterior views before linear ablation at the LA roof showing 2 activation fronts at the posterior wall. B, Anteroposterior and posteroanterior views after linear ablation at the LA roof showing the caudocranial activation of the LA posterior wall. AF indicates atrial fibrillation; AP, anteroposterior; LA, left atrium; PA, posteroanterior.

Figure 5.

Accumulated arrhythmia‐free survival (Kaplan‐Meier) after a single ablation procedure. A, Comparison between the LARA‐1 (solid line) and LARA‐2 (dotted line) groups. B, Comparison between the LARA‐1 patients that achieved conduction block at the roof (solid line), the LARA‐1 patients that did not achieve conduction block at the roof (slashed line), and the LARA‐2 patients (dotted line). LARA indicates left atrial roof linear ablation.

Figure 6.

Confirmation of persistent conduction block at the LA roof in a patient undergoing a repeat ablation procedure for recurrent paroxysmal AF. A, Color‐coded 3D activation map showing a caudocranial activation of the posterior wall. B, Double potential at the roof line (112 ms between spikes). AF indicates atrial fibrillation; LA, left atrium.