Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management, and outcome are sparse. This international multicentre registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553 729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed, at 214 centres in 35 countries. In 78 centres 138 patients [0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (P < 0.0001)] were diagnosed with an oesophageal fistula. Peri-procedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0–60) days and 21 (15, 29.5; range: 2–63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0–42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8% and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) [odds ratio 7.463 (2.414, 23.072) P < 0.001]. Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high. Summary of the POTTER-AF study results. CI, confidence interval; OR, odds ratio.

Background: Cryoballoon-based pulmonary vein isolation (PVI) has emerged as an effective treatment for atrial fibrillation. The most frequent complication during cryoballoon-based PVI is phrenic nerve injury (PNI). However, data on PNI are scarce. Methods: The YETI registry is a retrospective, multicenter, and multinational registry evaluating the incidence, characteristics, prognostic factors for PNI recovery and follow-up data of patients with PNI during cryoballoon-based PVI. Experienced electrophysiological centers were invited to participate. All patients with PNI during CB2 or third (CB3) and fourth-generation cryoballoon (CB4)-based PVI were eligible. Results: A total of 17 356 patients underwent cryoballoon-based PVI in 33 centers from 10 countries. A total of 731 (4.2%) patients experienced PNI. The mean time to PNI was 127.7±50.4 seconds, and the mean temperature at the time of PNI was −49±8°C. At the end of the procedure, PNI recovered in 394/731 patients (53.9%). Recovery of PNI at 12 months of follow-up was found in 97.0% of patients (682/703, with 28 patients lost to follow-up). A total of 16/703 (2.3%) reported symptomatic PNI. Only 0.06% of the overall population showed symptomatic and permanent PNI. Prognostic factors improving PNI recovery are immediate stop at PNI by double-stop technique and utilization of a bonus-freeze protocol. Age, cryoballoon temperature at PNI, and compound motor action potential amplitude loss >30% were identified as factors decreasing PNI recovery. Based on these parameters, a score was calculated. The YETI score has a numerical value that will directly represent the probability of a specific patient of recovering from PNI within 12 months. Conclusions: The incidence of PNI during cryoballoon-based PVI was 4.2%. Overall 97% of PNI recovered within 12 months. Symptomatic and permanent PNI is exceedingly rare in patients after cryoballoon-based PVI. The YETI score estimates the prognosis after iatrogenic cryoballoon-derived PNI. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03645577. Graphic A graphic abstract is available for this article.

Background: The contribution of autonomic influences to atrioventricular block (AVB) is unclear. Although cardioneuroablation has been used to treat cardioinhibitory vasovagal syncope, its role in treating functional paroxysmal and persistent AVB has not been formally evaluated. Methods: We used a stepwise protocol in 241 consecutive patients presenting with symptomatic AVB to identify 31 (12.9%) patients with functional or vagally mediated AVB. All patients had episode(s) of syncope in previous 12 months, and AVB was persistent in 17 (54.8%) patients. All 31 patients received targeted catheter-based cardioneuroablation, and their follow-up outcomes were evaluated with serial Holter monitoring. Results: Twenty-eight patients received biatrial or left-sided cardioneuroablation while 3 received only right-sided cardioneuroablation because of structural factors that precluded safe attempts at transseptal puncture. Procedural success, as defined as acute reversal of AVB and complete abolition of atropine response, was achieved in 30 (96.7%) cases, while the remaining patient received a pacemaker. Over a mean follow-up of 19.3±15 months, AVB episodes were observed in 2 (6.7%) of 30 cases, and 3 (9.6%) patients required pacemaker implantation during follow-up. Conclusions: Functional AVB can be identified in a minority of patients presenting with high-grade AVB. Cardioneuroablation for these patients results in encouraging medium-term outcomes.

Background: The aim of our study was to demonstrate the added value of routine transesophageal echocardiography (TEE) for correctly positioning the transseptal system in the fossa ovalis (FO), thus potentially preventing complications during fluoroscopy‐guided transseptal puncture (TP), and for assessing the optimal puncture site within the FO according to the expected procedure type.Methods: Ninety‐one patients undergoing pulmonary vein isolation (PVI) procedures by cryoballoon technique for drug‐resistant paroxysmal or persistent atrial fibrillation (AF) were prospectively included. In 57 patients, the TP procedure was performed under fluoroscopic guidance and septal localization was confirmed by contrast injection through the needle and demonstration of septal tenting in both the anteroposterior and left lateral fluoroscopic projections. In 34 patients, TP was performed under TEE guidance and positioning was targeted to perform the TP procedure in the more anterior and inferior locations of the FO. Two patient groups were compared according to the incidence of complications directly attributable to transseptal catheterization, thromboembolic complications, recurrence rates after the ablation procedure, total procedural time, and fluoroscopy time.Results: Fluoroscopy time (p<0.001), total cryoablation time (p=0.002), and total procedural time (p<0.001) were shorter in the TEE‐guided group. Left inferior pulmonary vein (LIPV) cryoablation time (p=0.007) and right inferior pulmonary vein (RIPV) cryoablation time (p=0.004) were significantly shorter and the number of applications to the LIPV (p=0.007) and RIPV (p=0.005) were significantly fewer in the TEE‐guided group. Although there was a trend toward higher complication rates (20.6% vs. 31.6%, p=0.37) and recurrence rates (11.8% vs. 20.1%, p=0.26) in the fluoroscopy‐guided group, the differences between the groups were not statistically significant.Conclusions: TEE‐guided TP for AF ablation is associated with shorter fluoroscopy time, shorter total cryoablation time, and shorter total procedural time. Importantly, TEE‐guided TP facilitates cryoablation of the inferior pulmonary veins.