Three-dimensional Left Atrial Volume assessed by CT predicts atrial fibrillation recurrence after re-do catheter ablation

Purpose atrial fibrillation (AF) is the most frequent arrhythmia worldwide. Catheter ablation is the most effective therapy, but 20% of patients still experience recurrences after two procedures. Cardiac computed tomography angiography (CCTA) is a highly efficient imaging technique to assess left atrial anatomy but is still not mandatory before ablation procedure. We sought to evaluate the prognostic value of CCTA left atrial (LA) parameters for the risk of AF recurrence after redo procedure. Methods we included retrospectively adults who underwent a second procedure of AF catheter ablation (AFCA) to measure 3D maximal indexed LA volume (LAV) on pre-procedural CCTA. Primary endpoint was the recurrence of AF after redo AFCA. Results between 2009 and 2019, 136 consecutive patients underwent a second AFCA at our institution, with 20% women. After a mean follow-up of 7 years, 62% of patients experienced AF recurrence. In multivariate analysis, a higher indexed LAV and female sex were the only independent variables associated with recurrence. An indexed LAV threshold of 84 ml/m² had the best performances to predict the risk of recurrent AF, with relatively low AUC (0.62). Conclusion this study is the first to evaluate the prognostic role of CT-LAVmax on the risk of recurrence after two ablation procedures. Despite suboptimal performances, it was the only imaging parameter associated with recurrent AF, with a threshold of 84 ml/m². Cut-off values for LAV could help physicians refining the selection of patients suitable for AFCA, to avoid futile interventions.