ABC | Volume 111, Nº6, December 2018

Original Article Paroxysmal Atrial Fibrillation Catheter Ablation Outcome Depends on Pulmonary Veins Anatomy Gabriel Odozynski, 1,2 Alexander Romeno Janner Dal Forno, 2 Andrei Lewandowski, 2 Hélcio Garcia Nascimento, 2 André d’Avila 2 Universidade Federal de Santa Catarina (UFSC), 1 Florianópolis, SC – Brazil Serviço de Arritmia e Marcapasso - Hospital SOS Cardio, 2 Florianópolis, SC – Brazil Mailing Address: Gabriel Odozynski • Rodovia SC 401 - Hospital SOS Cardio. Postal Code 88030-000, Itacorubi, Florianópolis, SC – Brazil E-mail: cardio.gabriel@gmail.com, gabrielodozynski@gmail.com Manuscript received March 27, 2018, revised manuscript June 10, 2018, accepted June 27, 2018 DOI: 10.5935/abc.20180181 Abstract Background: Pulmonary veins (PV) are often the trigger to atrial fibrillation (AF). Occasionally, left PVs converge on a common trunk (LCT) providing a simpler structure for catheter ablation. Objective: To compare the clinical characteristics and outcomes of ablation in paroxysmal atrial fibrillation (PAF) of patients with or without LCT. Methods: Case-control study of patients undergoing first-ever catheter ablation procedure for drug refractory PAF. The information was taken from patients’ records by means of a digital collection instrument, and indexed to an online database (Syscardio®). Clinical characteristics and procedures were compared between patients with or without LCT (LCT x n-LCT), adopting a level of statistical significance of 5%. The primary endpoint associated with efficacy was lack of atrial arrhythmia over the follow-up time. Results: One hundred and seventy two patients with PAF were included in the study, 30 (17%) LCT and 142 (83%) n-LCT. The clinical characteristics, comorbidities, symptoms scale and risk scores did not differ between the groups. There was AF recurrence in 27% of PAF patients in the n-LCT group and only 10% of patients in the LCT group (OR: 3.4 p: 0.04) after a follow-up of 34 ± 17 months and 26 ± 15 months respectively. Conclusion: Patients with a LCT have a significantly lower recurrence rate when compared to patients without this structure. It is mandatory to report the results of AF catheter ablation as a PV anatomical variation function. (Arq Bras Cardiol. 2018; 111(6):824-830) Keywords: Atrial Fibrillation/physiopathology; Arrhythmias, Cardiac; Catheter Ablation; Pulmonary Veins/physiopathology; Electrophysiologic Techniques, Cardiac. Introduction The electrical activity trigger responsible for triggering paroxysmal atrial fibrillation (PAF) is often located in the pulmonary veins (PV), so that the electrical isolation of the PVs is the therapeutic mainstem in the invasive treatment of this arrhythmia. 1-3 In most patients, four PV reach the left atrium. However, previous studies suggest that PV anatomical variations are related to a higher incidence of AF. 4,5 The left common trunk (fusion of the 2 left PVs in a common trunk [LCT]) is the most common of the PV anatomical variations, occurring in 4 to 18% of patients undergoing catheter ablation. 6 However, it is not clear whether the presence of these anatomical variations changes the outcome and the recurrence rates in the invasive treatment of PAF. As LCT can be easily identified by computed tomography (CT), knowing the clinical outcome of ablation in this population may be relevant in clinical decision-making when an ablative procedure is indicated. Therefore, the objective of this study was to compare the clinical characteristics and outcomes of patients undergoing PAF ablation with and without PV common left trunk. Methods Study design and participants This is a single-center, case-control study conducted between January 2011 and December 2015, with the inclusion of patients (≥ 18 years old) undergoing the first catheter ablation procedure to treat PAF that does not respond to antiarrhythmic drugs with a minimum follow-up of 12 months. The information was collected and indexed in a digital database aimed at AF ablation (SysCardio® software). Along with CT, the presence of the LCT was confirmed through 824