Data Collection
The NHR data encompassed all ablation procedures. From the NHR database
we obtained the data for the current analysis, including procedural
data, demographic characteristics, medical history, and data related to
prior ablation procedures. Starting from 2022, the ablation registry was
expanded to include an additional set of variables related to baseline
characteristics, procedural details, and follow-up data. This new
variable set encompassed the following variables: hypertension, coronary
artery disease (CAD), cerebrovascular accident/transient ischemic attack
(CVA/TIA), diabetes mellitus, pulmonary vein reconnection status,
ablation strategy used during repeat ablation, date of the last known
follow-up, use of anti-arrhythmic drugs at the time of the last
follow-up, date of recurrence after re-ablation, and type of atrial
arrhythmia recurrence. This expanded dataset was collected by eight
hospitals. Data regarding patients’ follow-up were obtained, including
recurrences after a 90-day blanking period, the use of antiarrhythmic
drugs during last known cardiac follow-up, and additional repeat
ablation procedures performed the first repeat procedure analyzed here.
Follow-up was calculated starting from the date of the first repeat
ablation. Follow-up occurred according to each center’s standard
protocol. Patients were usually scheduled for outpatient clinic visits
at 3-, 6-, and 12-months, and every 12 months thereafter. During these
visits, assessments were conducted for AF-related symptoms, adverse
events, and ECG or 24-hour Holter monitoring to detect any recurrence of
atrial arrhythmias, as determined by the physician’s discretion.
Patients were otherwise seen for emergency visits in case of symptomatic
recurrence, during which 12-lead ECG would be performed. The last known
follow-up was considered the end of the follow-up period for the
survival analysis, which was impacted by the occurrence of recurrence
and/or repeat ablation.