ABC | Volume 111, Nº6, December 2018

Original Article Odozynski et al PV anatomy and AF ablation Arq Bras Cardiol. 2018; 111(6):824-830 Figure 2 – Examples of patients with Common Trunk of the Left Pulmonary Veins (LCT) obtained from Computed Tomography performed before the catheter ablation procedure. In all cases, the left pulmonary veins coalesce before insertion into the left atrium and the minimum distance between the common ostium and the beginning of the bifurcation between the lower and upper branches of the common trunk is 10 mm. All the examples are in the posterior-anterior projection highlighting the posterior wall of the left atrium. Results One hundred and seventy-two patients were enrolled between 2011 and 2015 in a single center in Brazil. Thirty (17%) had LCT. There was no difference in follow-up time between cases and controls, with all patients completing a minimum follow-up of 12 months. Table 1 summarizes the clinical characteristics of patients with LCT and non-LCT undergoing PAF ablation during the study. Variables such as age (58 ± 10 vs 62 ± 11 years), gender (71% vs 69% men), BMI (28 ± 4 vs 27 ± 3.5 kg/m²), LVEF (65 ± 8% vs 66 ± 9%), diameter of the left atrium (38 ± 5 mm vs. 39 ± 6 mm) presented no differences between the non-LCT and LCT groups, respectively. The prevalence of other comorbidities including hypertension, diabetes mellitus, coronary artery disease and risk score (CHA 2 D 2 -VASc) for stroke were similar among the samples. There was no significant difference in the severity of symptoms associated with AF (CCS-SAF and EHRA scores) between cases and controls. Four percent of the patients had a previous history of stroke. Procedure efficacy and safety Table 2 shows a relapse rate for AF of 27% and 10% in the non-LCT and LCT groups (OR: 3.4; p: 0.04), after a follow-up time of 34 ± 17 and 26 ± 15 months respectively for cases and controls. Kaplan-Meier curve (Figure 3) highlights the lower proportion of relapse in the LCT group during the study. There were no major complications (TIA / stroke / Peripheral embolism, atrial-esophageal fistula or cardiac perforation / tamponade requiring surgery) related to procedures and / or hospitalization. Among the minor complications (inguinal hematoma, retroperitoneal bleeding, pseudoaneurysms or AV fistulas, PV stenosis, pericardial effusions or phrenic nerve palsy) there were 4 pseudoaneurysms and 1 inguinal hematoma, all in the non-LCT group, treated clinically without surgical intervention (Table 2). There were no deaths or reports of esophageal fistula during the study follow-up time. Discussion The durability of PVs electrical isolation is directly related to the efficacy of the percutaneous treatment of AF, so that PVs electrical reconnection seems to be the main mechanism for post-ablation AF relapse. 2,7-10 Our study suggests that pulmonary vein common left trunk patients have a more favorable clinical outcome after catheter ablation, with a clinical relapse around 10%. These results can be obtained without comprising procedure safety. LCT, when present, has been indicated as the predominant origin of the triggers of AF. 11 In the past, when the need for ablation of the 4 PV in the same procedure was still discussed, and maneuvers were used to trigger AF, some authors suggested that when AF originated in LCT, it was not necessary to perform right PV ablation. 12,13 Over the years, this concept proved to be inadequate because some recurrences occurred from foci in the right PVs. 2,8 For this reason, currently the information on the presence of the left common trunk helps more in the indication of the procedure rather than in the definition of the ablation strategy, which, unless otherwise indicated, will include the ablation of the LCT and the right PVs. 826