Periprocedural coagulability in patients undergoing ablation of atrial fibrillation: lessons from a periablation anticoagulation strategy of a brief withdrawal of warfarin without heparin bridging.

We aimed to examine what becomes of the coagulable state when warfarin is interrupted in patients undergoing ablation of atrial fibrillation (AF). We studied 62 patients with a CHADS2 score of 0 or 1 who underwent ablation for paroxysmal AF. Warfarin was discontinued the day before the ablation without heparin-bridging, and intravenous heparin was administered during the procedure in a conventional manner, and warfarin was then resumed after achieving hemostasis of the access site. The international normalized ratio (INR) values or D-dimer levels were measured at five different time points during the periprocedural period, and the periprocedural hemorrhagic and thromboembolic complications were assessed. The INR value constantly decreased after withdrawal of warfarin, and did not recover to the level before its discontinuation at the time of hospital discharge despite a short interruption of warfarin (mean ± SD, 1.75 ± 0.52 to 1.41 ± 0.27, p < 0.0001). However, the D-dimer level continued to increase over a period of 48 h after the ablation in spite of the administration of a sufficient amount of heparin during the procedure and a quick resumption of warfarin (mean ± SD, 0.57 ± 0.19 to 0.85 ± 0.36 μg/mL, p < 0.0001). The INR value measured just before the ablation had a significant inverse correlation to the D-dimer levels assessed just before (r = -0.304), immediately after (r = -0.440), 24 h after (r = -0.442) and 48 h after the ablation (r = -0.463). In conclusion, the risk of hyper-coagulability may increase during the early postprocedural period of AF ablation in patients who were inappropriately anticoagulated with warfarin.