Predictors for Permanent Pacemaker after Surgical “Box Lesion” Ablation of Atrial Fibrillation

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and associated with increased risk of morbidity and mortality. Concomitant surgical AF ablation is a safe and feasible procedure, recommended in guidelines. Permanent pacemaker implantation is a main complication of the procedure.

Objectives: We sought to determine predictors for pacemaker implantation after surgical AF ablation

Methods: Between January 2009 and June 2018. 208 patients underwent concomitant surgical AF ablation. Preoperative, intraoperative, and postoperative data were retrospectively collected. Univariate and multivariate logistic regression analysis was used to identify predictors for pacemaker implantation within 6 months after surgical AF ablation.

Results: The mean patient`s age was 64±10years, 56% were male. Paroxysmal atrial fibrillation 17%, Persistent 83% with the duration of 4.5±7years. Left atrial volume was larger in Bipolar group (138±59 cm³ vs 120±41 cm³, p=0.049). Ablation was done by bipolar (n=52) and Cryoablation (n=156) energy source. Left atrial (n=192, 92%) and bi-atrial (n=16, 8%) ablation was performed. No major ablation-related complications occurred. During 6 months follow up period, 3% (4/156 patients) received permanent pacemaker with Cryoablation and 10% (5/52 patients) with Bipolar energy source. Indications for pacemaker implantation were complete atrioventricular block in 6 (66%) of patients, sinus bradycardia 2 (22%) of patients, and Sick sinus rhythm in 1 (11%) of patients. Multivariable analysis showed that demographic data, type of surgical procedure did not have a significant impact on pacemaker implantation rate. However, bipolar energy source was a predictor for pacemaker implantation (95% CI 4.08 [1.045-15.9], p=0.043).

Conclusion: Concomitant surgical AF ablation precedes 4.3% incidence of Permanent pacemaker implantation after 6 months follow up. Univariate and multivariate analysis showed Bipolar Energy source as the only statistically significant predictor for pacemaker implantation after surgical AF ablation.