Surgical ablation for atrial fibrillation is efficacious in patients with giant left atria

Objective: The Cox-Maze IV procedure (CMP-IV) is the most effective treatment for atrial fibrillation. Increased left atrial (LA) size has been identified as a risk factor for failure to restore sinus rhythm. This has biased many surgeons against ablation in patients with giant left atrium (GLA), defined as LA diameter >6.5 cm. In this study we aimed to define the efficacy of the CMP-IV in patients with GLA. Methods: From April 2004 through March 2020, 786 patients with a documented LA diameter underwent elective CMP-IV, 72 of whom had GLA. Median follow-up duration was 4 years (interquartile range, 1-7 years). Recurrence was defined as any documented atrial tachyarrhythmia (ATA) lasting 30 seconds. ATA recurrence and survival were analyzed across GLA versus non-GLA groups. Results: Median age at surgery was 65 (interquartile range, 56-73) years. Median LA diameter within the GLA group was 7.0 (range, 6.6-10.0) cm. There were no differences in rates of postoperative complications for the 2 groups, including rate of postoperative stroke and pacemaker placement (GLA 14%; non-GLA 12%; P = .682). A trend toward increased 30-day mortality in the GLA group did not reach statistical significance (GLA 6%; non-GLA 2%; P = .051). Freedom from ATAs at 5 years postoperatively was comparable for the 2 groups (GLA 82%; non-GLA 84%). Conclusions: The CMP-IV had good efficacy in patients with GLA. Our results suggest that LA diameter>6.5 cm should not preclude a patient from undergoing surgical ablation for atrial fibrillation.