Short-term and mid-term effects of radiofrequency ablation in mitral valve surgery in patients with different left atrial sizes.

Background: To evaluate the efficacy of atrial fibrillation radiofrequency ablation (AFRA) in patients with chronic valvular atrial fibrillation (AF) with different left atrial sizes [left atrial diameter (LAD) >45 or ≤45 mm].

Methods: Between May 2016 and January 2019, 264 patients who underwent cardiac operations with modified bipolar AFRA in the Department of Cardiovascular Surgery, PLA General Hospital, were enrolled. The clinical data of the patients were analysed, and inclusion and exclusion criteria were implemented. A propensity score was given for two groups of different left atrial sizes: group A (75 patients with LAD >45 mm) and group B (75 patients with LAD ≤45 mm). Preoperative general data, operative indicators, postoperative mortality, complications, and sinus rhythm recovery were analysed and compared between the two groups.

Results: The rates of sinus rhythm recovery in group A (LAD >45 mm) at 1 week, 6 months, 1 year, and 2 years after surgery were 84.0%, 81.33%, 73.33%, and 69.33%, respectively, compared with 90.67.0%, 88.00%, 86.67%, and 84.00% at 1 week, 6 months, 1 year, and 2 years after surgery, respectively, in group B (LAD ≤45 mm). The difference between the two groups was statistically significant at the two points in time of 1 year, and 2 years (P<0.05). Warfarin anticoagulation, the standard therapy, was applied after surgery. No new cerebrovascular events occurred in either group during short- and medium-term postoperative follow-up.

Conclusions: Mitral valve surgery using improved Cox-Maze IV bipolar radiofrequency ablation was effective in treating chronic long-term persistent valvular AF and had an excellent sinus rhythm recovery rate. However, the larger the LAD, the less likely a patient was to maintain sinus rhythm as time passed after surgery.