2.1 Study population
Patients with drug-refractory AF who underwent de novo CB ablation using second-generation CB from July 2017 to February 2020 were included in this retrospective, single-center, non-randomized study. In order to establish the left atrial (LA) and PV anatomy, all patients underwent a computed tomography scan prior to ablation. All patients provided informed consent prior to the ablation procedure. We excluded those with left common PVs, huge PVs in which the CB was applied separately to the upper and lower parts of the PV, LA diameter >55 mm, intracardiac thrombi, uncontrolled thyroid dysfunction, contraindications for anticoagulation, and uncontrollable heart failure.
This study was conducted in accordance with the principles outlined in the Declaration of Helsinki. The study protocol was approved by the local institutional committee on human research at the Yokohama-City Bay Red Cross Hospital (approval number: 2017-81).