There has only been one completed trial of concomitant surgical AF ablation that has resulted in specific FDA labeling for clinical treatment of AF.1290 This was the Atricure Synergy Ablation System trial intended for the ablation of persistent and long-standing persistent AF in patients who are undergoing open concomitant coronary artery bypass grafting (CABG) and/or valve replacement or repair. The principal device used in this trial was an Atricure Synergy Ablation clamp. This system had originally been approved by the FDA for soft tissue ablation without specifically labeling for AF ablation. This prospective nonrandomized clinical trial, using a Bayesian adaptive design with prespecified early stopping rules, enrolled 55 patients between February 2008 and June 2009. Along with concomitant cardiac surgery, investigators performed the Cox-Maze IV lesion set. The median patient age was 72 years, the median EF was 50%, and the median LA size was 6 cm. 56% of patients underwent valve surgery alone or in conjunction with CABG. The incidence of major adverse events was 9%, including death in 2 patients (3.6%), major bleeding in 2 patients (3.6%), and stroke in one patient (1.8%). In addition to these major complications, 25% of the patients required implantation of a permanent pacemaker for AV node dysfunction (8.3%) or sinus node dysfunction (17%). The effectiveness of the procedure was assessed in 50 evaluable patients, excluding four patients who died and one withdrawal. At 6 months of follow-up, 74% of the patients were AF-free and off AAD therapy, and 84% of the patients were free of AF on or off AAD therapy. The freedom from AF at 12 months of follow-up was also 75%. The results of this study were reviewed at an FDA panel meeting, leading to approval for clinical use in 2011. This surgical ablation system is currently the only system specifically labeled for treatment of AF.