Outcomes of surgical ablation for atrial fibrillation in on- versus off-pump coronary artery bypass grafting

Objectives: A considerable number of patients undergoing coronary artery bypass grafting surgery suffer from atrial fibrillation and should be treated concomitantly. This manuscript evaluates the impact of on-pump versus off-pump bypass grafting on the applied lesion set and rhythm outcome.

Methods: Between January 2017 and April 2020, patients who underwent combined bypass grafting and surgical ablation for atrial fibrillation were consecutively enrolled in the German CArdioSurgEry Atrial Fibrillation registry (CASE-AF, 17 centres). Data were prospectively collected. Follow-up was planned after one year.

Results: A total of 224 patients were enrolled. No differences in baseline characteristics were seen between on- and off-pump bypass grafting, especially not in type of atrial fibrillation and left atrial size. In the on-pump group (n = 171, 76%), pulmonary vein isolation and an extended left atrial lesion set were performed more often compared to off-pump bypass grafting (58% vs 26%, 33 vs 9%, respectively, P < 0.001). In off-pump bypass grafting a box isolating the atrial posterior wall was the dominant lesion (72% off-pump vs 42% on-pump, P < 0.001). Left atrial appendage management was comparable in on-pump versus off-pump bypass grafting (94% vs 91%, P = 0.37). Sinus rhythm at follow-up was confirmed in 61% in the on-pump group and in 65% in the off-pump group (P = 0.66). No differences were seen in in-hospital or follow-up complication-rates between the two groups.

Conclusions: In coronary artery bypass grafting patients undergoing concomitant atrial fibrillation ablation, our data suggests that the technique applied for myocardial revascularization (off-pump vs on-pump) leads to differences in the ablation lesion set, but not in safety and effectiveness.