Background:
Pulmonary vein isolation (PVI) using cryoballoon (CB) ablation has comparable
efficacy and safety compared to radiofrequency ablation (RFA) for first
procedure treatment of symptomatic atrial fibrillation (AF). Redo procedures
are usually done with RFA, allowing for selective pulmonary vein re-isolation
as well as formation of additional lesion sets. It is unclear whether a
combination of different ablation methods in the index procedure and the redo
procedure provides an efficacy benefit compared to the use of RFA in both
procedures.
Aims: We aimed
to compare the efficacy and procedural characteristics of redo AF-ablation-procedures
in terms of the technology used in the first ablation procedure (Cryo vs. RFA).
Methods: We performed a
retrospective analysis of our internal AF ablation registry, containing 310
consecutive patients that underwent a second ablation procedure for recurrence
of symptomatic AF from November 2019 to August 2022. For 36 patients the method
in the first procedure was unknown or a method alternative to RFA or Cryo was
used, leaving 274 patients for analysis. Patients were stratified into two
groups, based on the technology used in the index procedure (Cryo vs. RFA).
Patients underwent follow-up at 3 and 12 months (at 12 months blanking phase
recurrences were excluded), either as part of a prescheduled visit or via
telephone call to the primary care provider or to the patient. Most of the
patients received a Holter-ECG over at least 24 hours during the follow-up
period or AF-recurrence was determined using an implanted device interrogation.
In addition, AF recurrence in the remaining patients was assessed on the basis
of symptoms and occasional ECGs during the follow-up period.
Results: 139 patients
underwent the index PVI using RFA vs. 135 patients in which the index procedure
was performed with Cryo. Baseline characteristics including sex (37.4% vs. 48.9% female, p=0.055), mean age (68.9 ±
9.7 vs. 68.7 ± 10.9 years, p=0.915), BMI
(26,8 ± 4.1 vs. 28.4 ± 4.3 kg/m2. p=0.345), percentage of patients with
paroxysmal AF (38.9% vs. 32.6%, p=0.280), arterial hypertension (69.6% vs.
67.4%, p=0.762), beta blocker use (84.1% vs. 80.7% p=0.472), class Ic or III antiarrhythmic drug
use on discharge (40.3% vs. 45.9%, p=0.346) and mean left atrial diameter (39.7
± 5.7 mm vs. 39.9± 5.6 mm. p=0.731) were all similar between groups.
In the redo procedures,
pulmonary vein reisolation was performed in 85.2% vs. 78.6% (p=0.204) after RFA
vs. after Cryo. Additional substrate modifications including lines and
defragmentation of low voltage potentials were done in 26.6% vs. 34.1% patients
(p=0.179).
Procedural duration (147.2
(110-180) vs. 139.0 (100-160) min, p=0.501), fluoroscopy time (12.1 (8.2-17.0)
vs. 13.1 (8.2-19.0), p=0,638), and fluoroscopy dose (2525 (1425-3935)vs. 2544
(1356-4840) mGycm2, p=0.806) were comparable between groups.
The rates of AF
recurrence at 3 month follow-up (27.0% vs. 26.4%, p=0.924) and 12 month
follow-up (25.6 vs. 34.5%, p=0.257) were similar between groups.
Conclusion: In this single center retrospective analysis, there
was no difference in efficacy and procedural characteristics of redo AF-ablation-procedures
based on the ablation method used in the index procedure.
Keywords: atrial fibrillation,
cryoballoon, radiofrequency, redo, pulmonary vein isolation