Study Population
The present study was a prospective observational study that included 81 consecutive patients with non-paroxysmal AF who underwent catheter ablation at our institution between November 2018 and April 2020. Five patients were excluded due to having no multidetector computed tomography (MDCT) images and 3 patients for undergoing additional LA ablation other than the PVI. Finally, a total of 73 persistent and longstanding persistent AF patients were investigated in this study. Persistent AF was defined as AF lasting ≥7 days but <1 year, and longstanding persistent AF as continuous AF lasting ≥1 year.17 All antiarrhythmic drugs were discontinued for at least 5 half-lives and one patient received oral amiodarone therapy before the catheter ablation. The protocol for this research project was approved by a suitably constituted Ethics Committee of Tohoku Medical and Pharmaceutical University (Date of IRB approval: February 25, 2019; Approval number, 2018-2-104) and it conformed to the provisions of the Declaration of Helsinki. All patients provided written informed consent for the ablation procedure, and the use of their anonymized data in this study.