ABC | Volume 110, Nº2, February 2018

Original Article Leiria et al Uninterrupted anticoagulants and flutter ablation Arq Bras Cardiol. 2018; 110(2):151-156 1. Doherty JU, Gluckman TJ, Hucker WJ, Januzzi JL, Ortel TL, Saxonhouse SJ, et al. 2017 ACC Expert Consensus Decision pathway for periprocedural management of anticoagulation in patients with nonvalvular atrial fibrillation: a Report of the American College of Cardiology Clinical Expert Consensus Document Task Force. J Am Coll Cardiol. 2017;69(7):871-98. doi: 10.1016/j.jacc.2016.11.024. 2. Kakkos SK, Kirkilesis GI, Tsolakis I. Editor’s choice: efficacy and safety of the new oral anticoagulants dabigatran, rivaroxaban, apixaban, and edoxaban in the treatment and secondary prevention of venous thromboembolism: a systematic review and meta-analysis of phase III trials. Eur J Vasc Endovasc Surg. 2014;48(5):565-75. doi: 10.1016/j.ejvs.2014.05.001. 3. Page RL, Joglar J, Caldwell M, Calkins H, Conti JB, Deal BJ, et al. 2015 ACC/AHA/HRS Guideline for the management of adult patients with supraventriculartachycardia:areportoftheAmericanCollegeofCardiology/ American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2015;67(13):e27-e115. doi: 10.1016/j.jacc.2015.08.856. 4. Spector P, Reynolds MR, Calkins H, Sondhi M, Xu Y, Martin A, et al. Meta-analysis of ablation of atrial flutter and supraventricular tachycardia. Am J Cardiol. 2009;104(5):671-7. doi: 10.1016/j. amjcard.2009.04.040. References The increasing use of NOACs since 2010, as demonstrated by the study GARFIELD-AF, 17 points to the need of data collection regarding the use of these classes of drugs in the most varied scenarios. The scenario of AFL ablation, however, requires prospective studies that are able to unify the conducts of the electrophysiology centers. Our study points to the security of these drugs and paves the way for the clinical trials to be conducted. One point to be emphasized in our study was the almost exclusive use of the 8mmablation catheter, whichmay not reflect the reality of other services. There is a sensation that, in the region of the cavotricuspid isthmus, whose thickness ranges between 0.5 and 5 mm, 18,19 the application of high energy (70 W) may lead to an increasing risk of perforation. However, the studies that assessed the use of 8 mm catheters, in comparison to irrigated ones, in the ablation of isthmus-dependent AFL, demonstrated there were no significant differences in the occurrence of vaporization lesions (“pop”) or cardiac perforation. 20-22 The occurrence of carbonization at the end of the catheter, however, seems to be higher than in the irrigated catheter, 20 but this fact was not measured in our study. Study limitations As limitations of our study, we mentioned that part of data collection was conducted retrospectively, through the analysis of medical records, which could lead to bias in the confirmation of the outcomes. However, our center presents a routine of peri and post-procedural care, which contemplates the collected variables, which mitigates the potential bias. Also, the number of patients analyzed may not have been sufficient to detect a statistically significant difference between the groups regarding the lower incidence outcomes. Another important aspect is that, even though the incidence density for ischemic events was higher in our study in the VKA group, this does not mean that one strategy is superior to another in the post-ablation period. As demonstrated, the patients using VKA have different characteristics than those using NOAC. The comparison between two distinct groups of patients is a significant limitation of this study. Besides the bias caused by the retrospective design, the VKA group presents almost 23% of the etiology patients (against none in the NOAC group). The valvar patients clearly presented with higher thromboembolic risk. Also, since this is an observational design, strategies for the strict control of therapeutic-target achieving (TTA) time were not conducted, and studies carried out in our service demonstrated mean TTA of about 50% in our population. 23 Conclusion This historical cohort points to the safety in the conduction of radiofrequency ablation of typical AFL procedures with the uninterrupted use of oral anticoagulants, regardless of the class of this group of medication. Author contributions Conception and design of the research and Analysis and interpretation of the data: Leiria TLL; Acquisition of data: Medeiros AK, Almeida ED, Ley ALG, Santos CBL; Statistical analysis: Medeiros AK, Ley ALG; Writing of the manuscript: Leiria TLL, Almeida ED, Sant’Anna RT, Pires LM, Lima GG; Critical revision of the manuscript for intellectual content: Sant’Anna RT, Kruse ML, Pires LM, Lima GG. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding There were no external funding sources for this study. Study Association This study is not associatedwith any thesis or dissertationwork. Ethics approval and consent to participate This study was approved by the Ethics Committee of the Instituto de Cardiologia / Fundação Universitária de Cardiologia under the protocol number UP 5252/16. All the procedures in this study were in accordance with the 1975 Helsinki Declaration, updated in 2013. Informed consent was obtained from all participants included in the study. 155