ABC | Volume 114, Nº5, May 2020

Short Editorial Sarabanda Risk of Atrial Fibrillation after Ablation Arq Bras Cardiol. 2020; 114(5):783-785 1-year follow-up (p=0.003). Subsequently, Romanov et al. 11 presented the extended (3-year) outcomes of the PREVENT AF I Study. There was a highly significant improvement in freedom from any atrial tachyarrhythmia in the CTI+PVI group compared with the CTI ablation only group (48% vs. 20%, P=0.01). Of note, there were no adverse events in the CTI+PVI group, but 2 strokes occurred in the CTI-only group during follow-up. In this study, a multivariate analysis identified male gender and age over 55 as factors that predicted atrial arrhythmias during follow-up. Additionally, the REDUCE AF study 12 randomized 216 patients with lone AFL to CTI+PVI versus CTI ablation alone, and found a reduction in subsequent AF with prophylactic PVI, but at the cost of significantly longer procedure and fluoroscopy times. In post hoc analysis, all of the benefit was confined to those patients over 55 years of age, in agreement with the findings of Romanov et al. 11 More recently, Gula et al. 13 conducted a cost-effectiveness analysis comparing the strategy of combined prophylactic PVI plus CTI versus sequential approach with separate procedures, i.e., waiting for AF to occur before undergoing PVI. Making plausible projections on AF occurrence and PVI success rates, as well as risks and costs of the procedures, the authors found that the combined approach with prophylactic PVI conferred higher risk and higher cost than the sequential approach during follow-up. However, one should consider the limitations of this study, and perhaps a strategy of combined prophylactic PVI plus CTI would have more favorable risk/benefit ratio if applied more selectively to patients at highest risk for developing AF during follow-up. In this context, as have been acknowledged by Bianco et al., 7 a significant limitation of their study was the limited size of the study population which may have prevented the identification of predictors for development of AF after CTI ablation. As recognized by the authors, 7 if a risk profile for the occurrence of AF following CTI-dependent AFL ablation could be determined, a combined approach, including ablation of both arrhythmias, could be prophylactically indicated in patients at higher risk for developing AF. In summary, the study of Bianco et al. 7 provides further evidence that CTI-dependent AFL ablation is a safe and effective procedure, but solves just part of the clinical problem of the patient presenting with isolated AFL, since the occurrence of AF after CTI ablation is frequently observed. However, with regard to the issue highlighted by the authors, 7 there is still insufficient evidence to recommend combined ablation for treatment of AFL aiming at preventing the occurrence of AF. Prospective studies with a larger number of patients and longer follow-up will are needed to assess the benefits of the simultaneous ablation. 1. PérezFJ,SchubertCM,ParvezB,PathakV,EllenbogenKA,WoodMA.Long-term outcomes after catheter ablation of cavo-tricuspid isthmus dependent atrial flutter: ameta-analysis. Circ ArrhythmElectrophysiol. 2009;2(4):393-401. 2. Page RL, Joglar JA, Caldwell MA, 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 AmColl Cardiol. 2016;67(13):e27-115. 3. Mittal S, Pokushalov E, Romanov A, Ferrara M, Arshad A, Musat D, et al. Long-term ECG monitoring using an implantable loop recorder for the detection of atrial fibrillation after cavotricuspid isthmus ablation in patients with atrial flutter. Heart Rhythm. 2013;10(11):1598-604. 4. Ellis K, Wazni O, Marrouche N, Martin D, Gillinov M, McCarthy P, et al. Incidence of atrial fibrillation post-cavotricuspid isthmus ablation in patients with typical atrial flutter: Left-atrial size as an independent predictor of atrial fibrillation recurrence. J Cardiovasc Electrophysiol. 2007;18(8):799-802. 5. Luria DM, Hodge DO, Monahan KH, Haroldson JM, ShenWK, Asirvatham SJ, et al. Effect of radiofrequency ablation of atrial flutter on the natural history of subsequent atrial arrhythmias. J Cardiovasc Electrophysiol. 2008;19(11):1145-50. 6. Waldo AL, Feld GK. Inter-relationships of atrial fibrillation and atrial flutter mechanismsandclinical implications.JAmCollCardiol.2008;51(8):779-86. 7. Bianco I, Silva GO, Forno ARJ, Nascimento HG, Lewandowski A, d’Avila A. Risco de fibrilação atrial após ablação flutter dependente de istmo vale a pena fazer ablação da FA simultaneamente? Arq Bras Cardiol. 2020; 114(5):775-782. 8. Tomson TT, Kapa S, Bala R, Riley MP, Lin D, Epstein AE, et al. Risk of stroke and atrial fibrillation after radiofrequency catheter ablation of typical atrial flutter. Heart Rhythm. 2012;9(11):1779-84. 9. Raposeiras-Roubín S, García-Seara J, Cabanas-Grandío P, Abu-Assi E, Rodríguez-Mañero M, Fernández-López JA, et al. Is safe to discontinue anticoagulation after successful ablation of atrial flutter? Int J Cardiol. 2015 Dec 15;201:631-2. 10. Steinberg JS, Romanov A, Musat D, PremingerM, Bayramova S, Artyomenko S, et al. Prophylactic pulmonary vein isolation during isthmus ablation for atrial flutter: the PReVENT AF Study I. Heart Rhythm. 2014;11(9):1567-72. 11. Romanov A, Pokushalov E, Bayramova S, Ponomarev D, Shabanov V, Losik D, et al. Prophylactic pulmonar vein isolation during isthmus ablation for atrial flutter: three-year outcomes of the PREVENT AF I study. J Cardiovasc Electrophysiol. 2018;29(6):872-8. 12. Mohanty S, Natale A, Mohanty P, DI Biase L, Trivedi C, Santangeli P, et al. Pulmonary vein isolation to reduce future risk of atrial fibrillation in patients undergoing typical flutter ablation: results from a randomized pilot study (REDUCE AF). J Cardiovasc Electrophysiol. 2015;26(8):819-25. 13. Gula LJ, Skanes AC, KleinGJ, Jenkyn KB, RedfearnDP, Manlucu J, et al. Atrial flutter and atrial fibrillation ablation - sequential or combined? A cost-benefit and risk analysis of primary prevention pulmonary vein ablation. Heart Rhythm. 2016;13(7):1441-8. References 784