Background: There is a concern about worsening of anemia after atrial fibrillation (AF) ablation in anemic patients. We aimed to clarify whether or not patients with anemia who are on an oral anticoagulant therapy are more likely to lose blood after AF ablation. Methods: We studied AF patients in 3 cardiovascular centers who skipped a single dose of direct oral anticoagulants prior to the ablation, and compared the drop in the hemoglobin level 24 hours after the procedure and bleeding complications between the patients with and without preexisting anemia. Results: We identified 183 (15.7%) patients with anemia at baseline out of 1163 patients. The reduction in the hemoglobin level (-0.39±0.71 vs. -0.93±0.9 g/dL; P<0.001) was smaller in the anemic than non-anemic patients. A fall in the hemoglobin level of ≥2 g/dL was less common in anemic patients (1.6% vs. 11.3%; P<0.001). A female gender (odds ratio [OR] 1.62, confidence interval [CI] 1.07-2.45; P=0.02), persistent or longstanding persistent versus paroxysmal AF (OR 1.67, CI 1.13-2.49; P=0.01), ORBIT score ≥3 (OR 3.5, CI 1.34-8.94; P=0.01), and preexisting anemia (OR 0.02, CI 0.004-0.14; P<0.001) were independently associated with the fall in the hemoglobin level of ≥2 g/dL. No difference was noted in the rate of major bleeding complications (1.6% vs. 1.2%; P=0.72). Conclusions: Paradoxically, patients with preexisting anemia may be less likely to lose blood following AF ablation.

Background: Thromboembolic or hemorrhagic complications related to atrial fibrillation (AF) ablation are rare, and thus, it is difficult to compare their frequency across different direct oral anticoagulants (DOACs). We aimed to compare the intraablation blood coagulability and postprocedural hemoglobin fall as alternatives to those complications across 4 DOACs. Methods: We enrolled AF patients younger than 65 years old in 3 cardiovascular centers who skipped a single dose of apixaban, dabigatran, edoxaban, and rivaroxaban, prior to the ablation. Endpoints included the activated clotting time (ACT), heparin requirement during the ablation, and drop in the hemoglobin level 24 hours after the procedure. Results: The time-course curves of the ACT differed significantly across the patients with apixaban (N=113), dabigatran (N=130), edoxaban (N=144), and rivaroxaban (N=81), with its highest level in the dabigatran group (P <0.001). The average ACT was greater in the dabigatran group than in the other groups (312.3±34, 334.4±44, 308.1±41, and 305.8±34.7 sec; P <0.001). A significant difference was noted in total heparin requirement across the patient groups (3990.2±1167.9, 3890.4±955.3, 4423.8±1051.6, and 3972±978.7 U/m2/h; P <0.001), with its greatest amount in the edoxaban group. The reduction in the hemoglobin level was similar (-0.93±0.92, -0.88±0.79, -0.89±0.97, -0.95±1.23 g/dL; P=0.94). No inter-group difference was noted in the rate of major or minor bleedings (0.9%, 2.3%, 1.4%, and 3.7%; P=0.51), and no thromboembolic events were encountered. Conclusion: A difference in DOACs may have an impact on intraablation anticoagulation, however, it may not on the procedural blood loss in the setting of a single skip.