Patients
A total of 1639 patients were considered eligible. Among them, 476 patients met the exclusion criteria; 21 with an inadequate dose reduction of DOACs, 285 with afternoon procedures, 201 with adjunctive ablation procedures including 78 cavotricuspid isthmus ablations, 69 linear lesions, 32 superior vena cava isolations, and 42 non-pulmonary vein trigger ablations. We thus finally studied 1163 patients. We found 183 (15.7%) patients with preexisting anemia, whose hemoglobin levels were 12±0.9 g/dL in males and 11.2±0.6 g/dL in females. No patients with severe anemia with a hemoglobin level of <9.0 g/dL were noted. Patients with preexisting anemia were older, smaller, and more likely to be female than those without. The anemic patients had a more decreased estimated glomerular filtration ratio, more increased D-dimer level, and greater CHA2DS2-VASc and ORBIT scores. The anemic patients were more likely to be prescribed with apixaban and a reduced dose of DOACs, and were less likely to be given dabigatran (Table 1). Although the etiology of the preexisting anemia had not been investigated in the majority of anemic patients at the referring clinics, renal insufficiency and iron deficiency were the dominant causes (Table 2).