Event recorder monitoring to compare the efficacy of a left versus biatrial lesion set in patients undergoing concomitant surgical ablation for atrial fibrillation

Objectives: Various lesion sets and subsequent success rates have been reported in patients receiving concomitant surgical ablation for atrial fibrillation. However, most of these results have been obtained by discontinuous monitoring. We report results using continuous event recorder rhythm monitoring to compare more accurately the efficacy of a left versus biatrial lesion set to treat patients with persistent atrial fibrillation.

Methods: Between July 2008 and December 2011, 66 patients with persistent or long-standing persistent atrial fibrillation underwent concomitant surgical atrial fibrillation ablation with a biatrial lesion set and subcutaneous event recorder implantation. The results and outcomes were compared with a propensity score-matched cohort of 66 patients with a left atrial lesion set and event recorder implantation. Event recorder interrogation was performed at 3, 6, and 12 months follow-up.

Results: The mean patient age was 70.2±7.4 years, and 70.3% were male. No major ablation-related complications occurred. One-year survival was 94.8% with no statistically significant differences between the 2 groups. The overall rate of freedom from atrial fibrillation was 57.3% and 64.4% after 3 and 12 months follow-up, respectively. Three months postoperatively, patients in the biatrial group had a slightly higher rate of freedom from atrial fibrillation (63.6% vs 52.3% P=.22), but it did not reach statistical significance. At 12 months follow-up, a statistically significant higher rate of freedom from atrial fibrillation was observed in patients with a biatrial lesion set (74.4% vs 55.8%; P=.026). The mean atrial fibrillation burden in all patients was 15.1%±12.5% in the biatrial group and 21.2%±14.4% in the left atrial group 12 months postoperatively (P=.03).

Conclusions: Continuous rhythm monitoring by subcutaneous event recorder implantation was safe and feasible. In patients undergoing biatrial ablation, a statistically significant higher rate of freedom from atrial fibrillation was observed at 12 months follow-up.