ABC | Volume 114, Nº3, March 2020

Original Article Safety of Catheter Ablation of Atrial Fibrillation Under Uninterrupted Rivaroxaban Use Márcio Augusto Silva , Guilherme Muller de Campos Futuro, Erick Sessa Merçon, Deborah Vasconcelos, Rovana Silva Agrizzi, Jorge Elias Net o, Ricardo Kuniyoshi Vitória Apart Hospital, Serra, ES – Brazil Mailing Address: Márcio Augusto Silva • Vitoria Apart Hospital – Cardiologia - Rodovia BR 101 Norte Km 2. Postal Code 29161-001, Boa Vista, Serra, ES – Brazil E-mail: masilva.cardio@gmail.com Manuscript received December 01, 2018, revised manuscript March 29, 2019, accepted May 15, 2019 DOI: https://doi.org/10.36660/abc.20180386 Abstract Background: Atrial fibrillation (AF) ablation under uninterrupted warfarin use is safe and recommended by experts. However, there is some controversy regarding direct-acting oral anticoagulants for the same purpose. Objective: To evaluate the safety of AF ablation under uninterrupted anticoagulation with rivaroxaban. Methods: A series of 130 patients underwent AF radiofrequency ablation under uninterrupted rivaroxaban use (RIV group) and was compared to a control group of 110 patients under uninterrupted warfarin use (WFR group) and therapeutic International Normalized Ratio (INR). We analyzed death, rates of thromboembolic events, major and minor bleedings, activated clotting time (ACT) levels, and heparin dose in the procedure. The ablation protocol basically consisted of circumferential isolation of the pulmonary veins guided by electroanatomic mapping. It was adopted a statistical significance of 5%. Results: The clinical characteristics of the groups were similar, and the paroxysmal AF was the most frequent type (63% and 59%, RIV and WFR groups). A thromboembolic event occurred in the RIV group. There were 3 patients with major bleeding (RIV = 1 and WFR = 2; p = 0.5); no deaths. Basal INR was higher in the WFR group (2.5 vs. 1.2 ± 0.02; p < 0.0001), with similar basal ACT levels (123.7 ± 3 vs. 118 ± 4; p= 0, 34). A higher dose of venous heparin was used in the RIV group (9,414 ± 199 vs. 6,019 ± 185 IU; p < 0.0001) to maintain similar mean ACT levels during the procedure (350 ± 3 vs. 348.9 ± 4; p = 0.79). Conclusion: In the study population, AF ablation under uninterrupted rivaroxaban showed a safety profile that was equivalent to uninterrupted warfarin use with therapeutic INR. (Arq Bras Cardiol. 2020; 114(3):435-442) Keywords: Catheter Ablation/methods; Atrial Fibrillation; Rivaroxaban /therapeitic use; Anticoagulants/therapeutic use; Anticoagulants/adverse effects. Introduction Catheter ablation is a well-established therapy for patients with atrial fibrillation (AF), particularly in symptomatic cases where antiarrhythmic drug control has failed. Its main technique consists in the electrical isolation of the pulmonary veins (PVs) through radiofrequency (RF) applications or cryoenergy in the atrial portion of the PV ostia. 1,2 Thromboembolic events (TE), especially cerebrovascular accident (CVA), or stroke, are among the most feared complications and, to avoid them, intraoperative intravenous systemic anticoagulation is recommended, with heparin and the use of oral anticoagulants (OAC) during the periprocedural period. 1,2 However, the management of these drugs becomes challenging during this period, as hemorrhagic complications can occur, especially hemopericardium (cardiac tamponade), a potentially fatal event if not diagnosed and addressed in time. Multicenter clinical studies have shown that continued use of warfarin during such procedures, while maintaining International Standardized Ratio (INR) at therapeutic levels, significantly reduces rates of bleeding complications and TE events when compared to the previous strategy, which consisted in its withdrawal and the “bridge” with unfractionated heparin. 3,4 With the advent of direct-acting OACs (DOACs), non-vitamin K-dependent, the use of warfarin has become increasingly restricted. Large-impact clinical studies have shown a safer profile of these drugs in relation to warfarin in the prevention of TE phenomena of patients with nonvalvular AF. 5 In recent years, DOACs have been tested against the scenario of AF ablation. Although evidence suggests the uninterrupted use of these drugs is safe, there is some controversy regarding their applicability due to fears of hemorrhagic complications in the presence of drugs that previously, did not have a direct reversing agent. Rivaroxaban, a factor Xa inhibitor, was one of the (DOAC) drugs that was most often tested in an uninterruptedly manner and the first to show satisfactory results in a randomized clinical trial. 6 435