Study patients
This single-center retrospective study included consecutive patients
with non-paroxysmal AF who underwent cryoballoon ablation with PVI
between January 2016 and December 2018. Patients who underwent heart
surgery were excluded because the surgery could have contributed to the
AT occurrence. Patients who underwent LA roof-line ablation using a
radiofrequency (RF) catheter were also excluded because the effect of
the ablation was considered to vary between LA roof-line ablation
performed with a cryoballoon and that performed with an RF catheter.
Patients who did not undergo clinical follow-up of more than 3 months
were excluded from the analysis. We hypothesized that LA posterior wall
(LAPW) ablation, including cryoballoon ablation of the LA roof in
addition to PVI, is effective in reducing the recurrence of persistent
AF in patients with non-paroxysmal AF without inducing AT. To compare
the effect of additional LAPW ablation with that of only PVI, only
patients who did not undergo MI ablation were analyzed; those who
underwent only LA roof-line ablation without LAPW bottom line ablation
were excluded. All patients underwent three-dimensional computed
tomography and transthoracic echocardiography before ablation.
Paroxysmal AF was defined as AF terminating within 7 days according to
the previously reported definition5; hence,
non-paroxysmal AF was defined as AF persisting for more than 7 days.
Baseline demographic characteristics, comorbidities, and medications
were recorded. Written informed consent was obtained from all patients
prior to the ablation procedure. This study was approved by our local
ethics committees and conform to the guiding principles of the
Declaration of Helsinki.