Pulmonary vein isolation using Ablation Index improves outcome in patients with atrial fibrillation

To evaluate the clinical outcome of pulmonary vein isolation (PVI) in radiofrequency ablation of atrial fibrillation (AF) comparing a strategy using Ablation Index (AI) and lesion contiguity with Contact Force (CF) only.

In a single-center retrospective design, we included 479 patients with AF (n=341 (71.2%) paroxysmal AF (PAF) and n=138 (28.8%) persistent AF (PeAF)) treated with first time radiofrequency ablation. In 2015, 210 patients underwent PVI based on a drag-and-ablate technique using CF only. In 2017, 269 patients underwent point-by-point PVI using AI and a maximum inter-lesion distance of 6 mm ensuring contiguity. Follow-up was performed after 12 months. Outcome was freedom from documented AF/atrial tachycardia (AT) after single procedure without use of anti-arrhythmic drugs at follow-up.

There was no significant difference in baseline characteristics between the groups. The median procedure time and mean ablation time were significantly longer in the AI-group compared to the CF-group (131.5[113;156] min vs. 120.0[97;140] min, P < 0.01) and (44.1±10.0 min vs. 37.1±13.3 min, P < 0.01), respectively. Freedom from documented AF/AT was significantly higher in the AI-group compared to the conventional CF -group (71.0% vs. 62.4%, P = 0.046). The improvement in clinical outcome in the AI group is mainly driven by the outcome in patients with PeAF (64.9% vs. 50.0%, P = 0.078) and not PAF.

An ablation strategy combining AI and lesion contiguity improves the clinical outcome after first time PVI in patients with AF compared to a strategy using CF only.