Left atrium size and the risk of atrio-esophageal fistula following thermal ablation in patients with atrial fibrillation

Abstract Introduction Prognostic value of the left atrial (LA) size for risk-stratification of atrio-esophageal fistula (AEF) in patients with atrial fibrillation (AF) undergoing thermal ablation procedures, remains unknown. Purpose This study aimed to investigate the significance of LA diameter (LAD) with regard to the risk of AEF in the POTTER-AF registry-patients versus typical AF population from a high-volume center. Methods This retrospective study included AEF patients from the international multi-center POTTER-AF registry (Group 1) and compared them with a control group with no AEF; i.e. consecutive patients receiving AF ablation at a high-volume center in 2022-23 (Group 2). All patients received thermal (radiofrequency or cryo-energy) ablations. LAD was measured using echocardiography at baseline. Multivariable logistic regression analysis was performed with age, gender, AF type, left ventricular ejection fraction, body mass index and CHA2DS2-VASc score entered as the variables. Results The study included 113 and 2105 patients in group 1 and 2 respectively. All in group 1 and none in group 2 had AEF reported following AF ablation. Baseline characteristics were similar between the groups except the number of redo ablations and radiofrequency time (Table 1). Mean duration to diagnosis of AEF in group 1 was 23.42 ± 12.30 days post-ablation. Mean LAD was significantly larger in group 1 vs group 2 (41.94 ± 6.27 vs 40.15 ± 3.46 mm, p<0.001). Moderate to severe dilation (LAD ≥47 mm) was detected in 12 (10.6%) in group 1 and none in group 2 (p<0.001). In the multivariable logistic regression analysis, LAD was an independent predictor of AEF (OR =4.449 95% CI 1.284 – 3.635; p- value <0.001). Conclusion Data from the current study suggest direct association of moderate-severe LA enlargement with the risk of AEF. Thus, operators need to be cautious while ablating left atrial posterior wall in patients with dilated left atrium.Table 1