Study design and patient population
The present study is an observational, retrospective, multicenter, real-world cohort study performed at 8 centers in the Netherlands. We identified all repeat ablations performed in these centers between 2016-2019 through the Netherlands Heart Registration (NHR). The NHR is a nationwide, non-voluntary, quality monitoring registry in the Netherlands dedicated to collecting comprehensive data on cardiovascular diseases and interventions, including all AF ablations performed in the Netherlands since 2013.(14) With regards to ablation procedures, the collected data include demographic characteristics, including medical history, and procedural data related to the ablation procedures (detailed overview of the variables included in the NHR ablation registry (15)). The study was approved by the institutional review board MEC-U (W19.270) and conducted in accordance with the principles of the Declaration of Helsinki. A waiver of informed consent was obtained for the analysis of data from the NHR data registry.
The inclusion criteria for the study were the following: (1) a history of paroxysmal or persistent AF (defined respectively as AF that terminates spontaneously or with intervention within 7 days of onset and AF that is sustained for more than 7 days, or less than 7 days but requires pharmacological or electrical cardioversion to terminate) treated with ablation procedure(s) consisting solely of PVI; (2) documented AF recurrence (12 lead ECG, Holter, ECG rhythm strips) after the 1st ablation procedure; (3) first repeat ablation performed between 2016 and 2019 during which all PVs were durably isolated on electrophysiological mapping.
Patients were excluded if they underwent surgical ablation during prior procedures or other lesions were performed during the prior ablations (except for cavo-tricuspid isthmus ablation), or if the indication of the repeat procedure was for atrial tachycardia (AT) or atrial flutter (AFL).