Study population
Patients with persistent or long-standing persistent AF who were scheduled for CA and enrolled at the Japan Red Cross Yokohama City Bay Hospital from January 2018 to July 2020 were included in this study. Patients were excluded if they had an allergy to the contrast agent, renal dysfunction, or severe mitral valve disease, or were intolerant to oral anticoagulants. All patients were prescribed oral anticoagulants for at least 4 weeks prior to the CA procedure. The study protocol was approved by the ethics committee of the Japan Red Cross Yokohama City Bay Hospital, and written informed consent was obtained from all the participants before study initiation.