Implantable Loop Recorder Monitoring following Concomitant Surgical AF Ablation

Objectives: Various follow-up methods have been used to measure success rates after AF ablation. Intermittent rhythm monitoring strategies have been shown to underestimate the actual AF recurrence rate. We therefore report our experience with continuous rhythm monitoring by implantable loop recorder (ILR) implantation.

Methods: Between 2008 and 2014 432 cardiac surgical patients underwent concomitant surgical AF ablation. ILR implantation was performed in 221 patients. ILR interrogation was performed 3, 6 and 12 months postoperatively. Successful ablation was defined as AF Burden < 0.5%. Primary study endpoint was freedom from AF at 12 months follow-up.

Results: Mean patient's age was 69.1 ± 634 years. No major ablation- or ILR related complications occurred. In 4 patients (1.8%) ILR had to be explanted due to ILR-related wound infection (n = 2) or chronic pain (n = 2). Survival rate at one-year follow-up was 96.9%. Freedom from AF rate after one-year follow-up was 67.1%. In multivariate analysis, statistically significant predictors for successful ablation at one-year follow-up were smaller LA diameter, shorter duration of AF and preoperative paroxysmal AF. In patients with failure of ablation, mean AF burden was 33.1 ± 23.1% corresponding to a mean time of 7.9 hours per day spent in AF. A very heterogeneous pattern of AF distribution was seen among patients with AF recurrence.

Conclusion: Continuous ILR monitoring after concomitant surgical AF ablation showed freedom from AF rate 67.1% at one-year follow-up. A very heterogenous pattern of AF distribution in patients with AF recurrence was observed, emphasizing the importance of continuous rhythm monitoring to guide antiarrhythmic therapy and to allow for safe withdrawal of anticoagulation therapy.