ABC | Volume 110, Nº2, February 2018

Original Article Leiria et al Uninterrupted anticoagulants and flutter ablation Arq Bras Cardiol. 2018; 110(2):151-156 Figure 1 – Study flowchart. CTI: cavotricuspid isthmus dependent flutter; OAC: oral anticoagulation; NOAC: non-vitamin K antagonist oral anticoagulants; VKA: vitamin K anticoagulant antagonists. 5.506 electrophysiological procedures 288 atrial flutter ablations Excluded 134 patients – left atrial flutter – without the uninterrupted use of OAC 154 CTI flutter ablations with uninterrupted use of OAC 65 NOAC 89 VKA The VKAs were used uninterruptedly in 57.8% of the cases, and NOACs, in 42.2% of the participants. The mean INR was 2.54 ± 0.54 in the VKA group on the day of the ablation. The patients using NOAC were the majority at a sinus rhythm on the day of the ablation. These patients had smaller left atriums. Besides, they also used more antiarrhythmic drugs, less beta‑blockers and statins, with lower prevalence of previous heart surgery when compared to patients using VKA. Table 1 shows the clinical characteristics of the patients stratified by type of anticoagulant used. Table 2 exemplifies the frequency of use of different types of NOACs and VKAs used in the study. The rates of hemorrhagic complication related with the procedure was 3% in each group (p = 0.97). There were no cases of cardiac tamponade or major hemorrhagic complication in the patients of the study. The main complications related with the procedure were inguinal hematomas. The rate of stroke / TIA was 57/1,000 people-year in the VKA group against zero/1,000 people-year in the NOAC group (p = 0.02). Discussion Our study shows the safety of the use of oral anticoagulants (VKAs or NOACs) in the periprocedural period of the radiofrequency ablation of typical AFL. The use of periprocedural anticoagulation is based on the frequent finding of atrial thrombi or of spontaneous echo contrast in the transesophageal echocardiogram. 11 The studies about the oral anticoagulation in these patients, however, are scarce, and there are no clear recommendations in the guidelines about the handling of periprocedural anticoagulation for the ablation of AFL. 8,12-14 A retrospective study with 254 patients, comparing periprocedural warfarin and dabigatran of ablation of AFL and AF, demonstrated similar results to that of our cohort, with low rates of thromboembolic and hemorrhagic complications. However, the authors do not show the number of patients with AFL included in the study. 12 A second retrospective study with 60 patients who used dabigatran or rivaroxaban in the periprocedural period of AFL ablation demonstrated low incidence of hemorrhagic complications, with 4 minor bleedings (3 of the 23 patients using dabigatran 150 mg b.i.d, and 1 of the patients using rivaroxaban 20 mg), and no major bleeding. A second retrospective study with 60 patients who used dabigatran or rivaroxaban in the periprocedural period of AFL ablation demonstrated low incidence of hemorrhagic complications, with 4 minor bleedings (3 of the 23 patients using dabigatran 150 mg b.i.d. and 1 of the 11 patients using rivaroxaban 20 mg), and no major bleeding. A patient using dabigatran 110 mg b.i.d. presented with ischemic stroke 27h after the procedure, in the uninterrupted use of anticoagulant, with preprocedural transesophageal echocardiogram that did not show atrial thrombi. This study, however, collected data only until the hospital discharge of the patients; therefore, the security data of the use of these medications may be underestimated. 15 153