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).