Correlation between tracheal carina angle and recurrence in atrial fibrillation patients undergoing catheter ablation: Is epicardial reactivation the major game changer in AF ablation success?

Abstract Background Catheter ablation is a well-known and appropriate treatment modality in terms of side-effect profile and efficacy compared to anti-arrhythmic drugs in the treatment of Atrial Fibrillation (AF). However, our knowledge on success criteria and prediction of recurrence in patients undergoing catheter ablation is still limited. Previously various clinical, laboratory and imaging methods have been used to assess the recurrence of AF after ablation procedure. Aims The aims of this study are to investigate the effects of epicardial fat volume (EFV), left atrium (LA) and pulmonary vein (PV) measurements evaluated with multimodal imaging methods, in addition to laboratory and clinical parameters, on acute and long-term outcomes of AF ablation. Methods 210 patients with AF who underwent catheter ablation were enrolled in the study, which was designed as a retrospective cohort model. Due to insufficient data, 22 patients were excluded before the analysis phase. In the biostatistical analysis, T-test, Mann-Whitney and Fisher's exact test were used in accordance with the data characteristics. The receiver-operating characteristic (ROC) curve was used to determine the cut-off for variables with a statistically significant p value to predict the recurrence. Results A total of 188 patients are included in the study cohort. Among the studied 188 cases, AF recurrence occurred in 32 (17%). A ROC curve analysis showed that the best cut-off value of Tracheal Carina Angle (TCA) for predicting recurrence was 58.5 degree with a sensitivity and specificity of %72 and %80, respectively (AUC,0.809; %95 CI, 0.712-0.906). Also EFV appeared to somewhat statistically related with AF recurrence with a P value of 0.07. Of note, PV angles in transverse section were insignificant in a scope of AF recurrence (RSPV: Right Superior Pulmonary Vein p=0.7; RIPV: Right Inferior Pulmonary Vein p=0.3; LSPV: Left Superior Pulmonary Vein p=0.3; LIPV: Left Inferior Pulmonary Vein p=0.3). The results of the logistic regression model showed that TCA was a significant risk factor for AF recurrence (p<0.01). A one-degree increase in TCA was associated with an 8.4% increase in the odds of AF recurrence. EFV was not a statistically significant predictor of AF recurrence. Conclusion By mainly mechanical stretch and ischemia, the left atrial enlargement pattern affects the pulmonary vein orientation and epicardial reactivation, especially due to proximity to tracheal carina, left and right main bronchus. Previous studies have shown that pulmonary vein orientation is an important indicator for recurrence after catheter ablation in patients with AF. In this study, the TCA was significantly correlated with recurrence after catheter ablation.Figure 2