Abstract 2477: Is Surgical Ablation a Durable Treatment for Atrial Fibrillation?
INTRODUCTION: Surgical treatment of atrial fibrillation (AF) by left atrial ablation is thought to reduce cardiac morbidities and death. Previous reported results with AF ablation at 6 and 12 months follow-up have been used to justify discontinuation of anticoagulation. The purpose of our study is to examine the durability of concomitant surgical ablation for AF.
METHODS: Between January 2002 and October 2008, 134 consecutive patients (39% female, mean age 67.2±9.9) underwent surgical ablation for AF and concomitant: mitral valve surgery (61%), isolated coronary artery bypass grafting (27%) and other cardiac procedure (12%). AF was paroxysmal in 49 patients (36%), persistent in 24 (18%) and permanent in 62 (46%). Pulmonary vein isolation with or without left atrial appendage closure and/or extending lesion to the mitral valve annulus was performed by radiofrequency (44%), ultrasound (44%) and cryoablation (12%). Follow-up by 24 hour Holter monitor or ECG was conducted at 6 and 12 months, and annually thereafter.
RESULTS: Three year survival was 83% (95% CI, 73–90%). Four patients were lost to follow-up. Median follow-up time was 1.5 years (IQR 0.9–3.1). There were 11 in-hospital deaths, 4 strokes and 13 pacemaker implantations. Twelve patients were readmitted to hospital for AF. Prevalence of AF at 6 months was 17% and at 12 months was 41%. However, overall freedom from first recurrence of AF for all patients with at least 6 months follow-up was only 53% (95% CI, 41–63%) at 2 years. AF at 12 months was associated with left atrial size >5cm (p=.04) but not with duration or type of AF (p>.05). There was no difference in prevalence of AF among procedure groups.
CONCLUSIONS: Documentation of absence of AF at both 6 and 12 months follow-up is not adequate to confirm ablation success. Despite a reduction in the burden of AF, many patients experience recurrence of AF over time. The long-term benefit is uncertain and may not be durable; therefore, confirmation of cure and cessation of anticoagulation would require more intensive monitoring and indefinite follow-up.