Introduction
Catheter ablation of atrial fibrillation (AF) has become the first-line treatment for a selected population [1]. Oral anticoagulation remains an essential treatment for patients with AF regardless of whether or not they undergo the ablation. Anemia is often encountered in subjects with AF who are on anticoagulant treatment with direct oral anticoagulants (DOACs) in clinical practice [2]. To date, preexisting anemia is not considered a predictor of major hemorrhagic complications during the periablation period [3]. Still, there is concern about further blood loss due to the ablation procedure in anemic patients since it requires an insertion of several large-diameter vascular sheaths and intense intraprocedural anticoagulation with heparin [3]. We then in the present study sought to investigate whether there was a difference in blood loss following AF ablation between patients with and without preexisting anemia.