Impact of radiofrequency characteristics on acute pulmonary vein reconnection and clinical outcome after PVAC ablation.

Objective: The objective was to study the impact of radiofrequency (RF) characteristics on acute pulmonary vein reconnection (PVR) and outcome after PVAC ablation. PVI with additional ablation of PVR (PVI + PVR) was compared to PVI-only.

Methods: In 40 consecutive patients, after PVAC-guided PVI, adenosine and a 1-hour waiting time were used to unmask and ablate acute PVR (PVI + PVR group). RF-characteristics and 1-year AF freedom were compared post hoc to 40 clinically matched patients undergoing PVI only (PVI-only group). Custom-made software was used to assess RF characteristics of the PVAC applications needed to obtain baseline PVI.

Results: There was no difference in clinical characteristics or baseline RF-profile between both groups. Acute PVR was observed and ablated in 38 of 160 veins (24%). AF-freedom after PVI + PVR was higher than PVI (85% vs 65%, P < 0.05). Within the PVI group, comparing patients with and without AF-recurrence, the percentage of PVAC applications with high T° (>48°) but low power (<3W) was higher (28 ± 18% vs 11 ± 11%, P < 0.0001). Within the PVI + PVR group, when comparing PVs with and without PVR, the percentage of low power/high T° PVAC applications was also higher (27 ± 13% vs 13 ± 15%, P < 0.0001).

Conclusions: (1) After PVAC ablation, 24% of PVs exhibit acute reconnection. Additional ablation of reconnection improves clinical outcome. (2) Acute reconnection as well as clinical recurrence of AF are characterized by PVAC ablation with a considerable number of applications with high temperature but low power. (3) If PV isolation is obtained with low power applications, a consistent use of both adenosine and waiting time is required.