Predictors of atrial fibrillation recurrence after pulmonary vein ablation: Clinical and radiological risk factors

Abstract

Background and objective

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide. Previous studies have described that certain clinical characteristics such as age, obesity, the type of AF, and imaging-based factors, such as left atrial (LA) volume, mean density (calculated as the average of Hounsfield Units values in a certain región of interest), and volume of cardiac adipose tissue, may increase the risk of recurrence following pulmonary vein ablation. However, there have been contradictory results regarding radiological variables in previous studies. The objective of this study was to evaluate these clinical and radiological risk factors obtained from computed tomography (CT) studies.

Materials and methods

This retrospective case-control study included all patients with AF who underwent initial radiofrequency or cryoablation of pulmonary veins after undergoing contrast-enhanced CT between 2017 and 2021. Clinical variables such as age, gender, comorbidities, medications used after ablation, type of AF, and radiological variables obtained from volumetric segmentation of CT studies were collected. Radiological variables included LA volume, mean density, and volume of epicardial, periatrial, and interatrial adipose tissue. The occurrence or absence of AF recurrence within 12 months after ablation was also recorded. These variables were subjected to univariate and multivariate analysis to evaluate the risk of recurrence.

Results

Among the total number of included patients, 40 had paroxysmal AF and 12 had persistent AF. During the follow-up period, 12 patients (23.1%) experienced AF recurrence, while 40 patients (76.9%) remained in sinus rhythm. There were statistically significant differences in LA volume based on the type of AF, with higher volumes observed in patients with persistent AF (119.16 +/− 32.38 cc) compared to the rest (90.99 +/− 28.34 cc). Regarding the differences between patients with and without recurrence after ablation, only LA volume (p < 0.05) and periatrial adipose tissue volume (p < 0.01) were significantly higher in patients with recurrence.

Conclusion

The type of atrial fibrillation, increased left atrial volume, and increased periatrial adipose tissue volume are risk factors for recurrence in patients with atrial fibrillation undergoing pulmonary vein ablation using cryoablation or radiofrequency.