Study design and population
This study retrospectively analyzed data obtained from the AF ablation database of Tokyo Women’s Medical University. From January 2011 to March 2020, 1340 patients had undergone AF ablation at our institution. We excluded 266 patients who did not undergo SVCI. Thirty-four patients who had received CIED implantation before SVCI were enrolled in this study (CIED group), and 34 age-, sex- and AF type-matched patients without CIEDs comprised a control group (non-CIED group). Experienced physicians undertook the data collection, based on individual chart reviews. The following data were used as baseline characteristics: age, sex, height, body weight, AF type, structural heart diseases, echocardiographic parameters, and B-type natriuretic peptide levels. Procedural characteristics were also assessed. Baseline patient and procedural characteristics were compared between the CIED and non-CIED groups. In the CIED group, detailed device-related and lead-related information was studied, along with lead parameters before and after SVCI. Lead positions were also evaluated using computed tomography imaging before AF ablation at the level of the left atrium roof, and these were divided into 4 portions, namely, the anterior, septal, posterior, and lateral portions of the SVC.
The study protocol conformed to the ethical guidelines of the 1975 Declaration of Helsinki and was approved by the Institutional Review Board and Ethics Committee of the Tokyo Women’s Medical University. Written informed consent was obtained from all patients.