Impact of a time-to-effect guided ablation protocol in cryoballoon
ablation on durability of pulmonary vein isolation
Abstract
Background: Cryoballoon (CB) based pulmonary vein isolation (PVI) has
proven to be as effective as radiofrequency (RF) based ablation.
Different ablation protocols took the individual time-to-isolation (TTI)
into account aiming at shorter but equally or even more effective
freeze-cycles. The current study sought to assess the impact of the TTI
on PVI durability in patients undergoing a repeat procedure for
recurrence of atrial tachyarrhythmia (ATA). Methods and Results: In 205
patients with ATA recurrence after previous CB-based PVI a total of 806
PVs were identified. One hundred-twenty-six out of 806 PVs (16%) were
previously treated with a TTI guided ablation (protocol #1; TTI+120
sec.), in 92/806 (11%) PVs TTI was only monitored (m) but fixed
freeze-cycles were applied (protocol #2; mTTI) and in 588/806 (73%) a
fixed freeze-cycle was applied without TTI-monitoring. There was no
difference in the PV-reconduction rate between the groups (P=0.23). The
right inferior pulmonary vein (RIPV) showed overall significantly higher
reconduction rates compared to the other PVs (RIPV – left inferior PV
(LIPV) p<0.003, -left superior PV (LSPV) p<0.001, -
right superior PV RSPV p<0.013). In 21 patients (10%) only
for the RIPV reconduction was assessed. Conclusions: TTI based CB
ablation did not show significant differences regarding PV-reconduction
rates compared to the other protocols.