Anemia and atrial fibrillation ablation recurrence: insights from a large-scale multicentre registry

Abstract Background Both atrial fibrillation (AF) and anemia are associated with an increased mortality, and they often coexist. Whether anemia is associated with arrhythmia recurrence after catheter ablation (CA) of AF remains unknown. Methods We conducted a large-scale, prospective, multicentre, observational study (Kansai Plus Atrial Fibrillation Registry). Out of 5010 consecutive patients who underwent an initial radiofrequency CA (RFCA) of AF at 26 centres, we enrolled 4966 patients whose hemoglobin data were available (age 64.4 years, 27.3% female, and 35.6% non-paroxysmal AF). The entire cohort was divided into three subgroups according to the WHO classification of anemia: normal (hemoglobin ≥ 13.0 g/dL in men and ≥ 12.0 g/dL in women, n=4300, 86.6%), mild anemia (11.0 ≤ hemoglobin < 13.0 g/dL in men and 11.0 ≤ hemoglobin < 12.0 g/dL in women, n = 519, 10.5%), and moderate-severe anemia (