The efficacy of intraoperative atrial radiofrequency ablation for atrial fibrillation during concomitant cardiac surgery-the Surgical Atrial Fibrillation Suppression (SAFS) Study

Mid-Term Results of Surgical Treatment of Atrial Fibrillation in Valvular Heart Disease Assesed by Speckle Tracking Echocardiography

Background

Atrial fibrillation frequently affects patients with valvular heart disease. Ablation of atrial fibrillation during valvular surgery is an alternative for restoring sinus rhythm.

Objectives

This study aimed to evaluate mid-term results of successful atrial fibrillation surgical ablation during valvular heart disease surgery, to explore left atrium post-ablation mechanics and to identify predictors of recurrence.

Methods

Fifty-three consecutive candidates were included. Eligibility criteria for ablation included persistent atrial fibrillation <10 years and left atrium diameter < 6.0 cm. Three months after surgery, echocardiogram, 24-hour Holter monitoring and electrocardiograms were performed in all candidates who maintained sinus rhythm (44 patients). Echo-study included left atrial deformation parameters (strain and strain rate), using 2-dimensional speckle-tracking echocardiography. Simultaneously, 30 healthy individuals (controls) were analyzed with the same protocol for left atrial performance. Significance was considered with a P value of < 0.05.

Results

After a mean follow up of 17 ± 2 months, 13 new post-operative cases of recurrent atrial fibrillation were identified. A total of 1,245 left atrial segments were analysed. Left atrium was severely dilated in the post-surgery group and, mechanical properties of left atrium did not recover after surgery when compared with normal values. Left atrial volume (≥ 64 mL/m²) was the only independent predictor of atrial fibrillation recurrence (p = 0.03).

Conclusions

Left atrial volume was larger in patients with atrial fibrillation recurrence and emerges as the main predictor of recurrences, thereby improving the selection of candidates for this therapy; however, no differences were found regarding myocardial deformation parameters. Despite electrical maintenance of sinus rhythm, left atrium mechanics did not recover after atrial fibrillation ablation performed during valvular heart disease surgery.

Surgical perspectives in the management of atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia and a huge public health burden associated with significant morbidity and mortality. For decades an increasing number of patients have undergone surgical treatment of AF, mainly during concomitant cardiac surgery. This has sparked a drive for conducting further studies and researching this field. With the cornerstone Cox-Maze III “cut and sew” procedure being technically challenging, the focus in current literature has turned towards less invasive techniques. The introduction of ablative devices has revolutionised the surgical management of AF, moving away from the traditional surgical lesions. The hybrid procedure, a combination of catheter and surgical ablation is another promising new technique aiming to improve outcomes. Despite the increasing number of studies looking at various aspects of the surgical management of AF, the literature would benefit from more uniformly conducted randomised control trials.

Radiofrequency ablation of atrial fibrillation during mitral valve surgery

Objectives

Atrial fibrillation is the most common form of arrhythmia in mitral valve disease. Radiofrequency ablation is most commonly used for atrial fibrillation ablation during mitral valve surgery.

Methods

This prospective study evaluated the midterm outcomes of intraoperative radiofrequency atrial fibrillation ablation during mitral valve surgery.

Results

52 patients were eligible for the study. Fifteen (28.8%) had a transseptal approach and 37 had a left atriotomy. Mitral valve replacement was performed in 16 patients, mitral valve repair in 31, and tricuspid repair in 8. Mean crossclamp time was 58.14. ± 20.08 min, and mean cardiopulmonary bypass time was 71.28 ± 20.31 min. The mean ablation time was 6.41 ± 0.21 min. There was no postoperative mortality. Sinus rhythm was documented in 44 (84.6%) patients on discharge, and 8 (15.4%) were discharged with atrial fibrillation; 2 of them returned to sinus rhythm after 3 months. After 12 months of follow-up, 46 (88.5%) patients were in sinus rhythm.

Conclusion

Left atrial monopolar radiofrequency ablation during mitral valve surgery is a safe procedure with a high success rate.