Left-Sided Surgical Ablation for Patients With Atrial Fibrillation Who Are Undergoing Concomitant Cardiac Surgical Procedures.

BACKGROUND: Growing evidence indicates the effectiveness of surgical ablation confined to the left atrium, especially with short duration of atrial fibrillation (AF) and smaller left atrial (LA) size. This study examined rhythm status and predictors of failure in this group of patients.

METHODS: Of 800 patients who underwent concomitant surgical ablation (2005 to 2015), 110 had LA-only ablation. Rhythm status was defined according to Heart Rhythm Society guidelines: sinus rhythm (SR) without class I/III antiarrhythmic drugs (AADs). Multivariate analyses examined predictors for SR without AADs. Predictors of failure were also stratified as age 75 years or older, LA size 5 cm or larger, AF duration 5 years or more, and nonparoxysmal AF type for secondary analyses.

RESULTS: Mean age was 70.7 ± 9.4 years, mean EuroSCORE II (European System for Cardiac Operative Risk Evaluation) was 4.7 ± 4.3%, mean LA size was 4.4 ± 0.8 cm, median (interquartile range) AF duration was 3.5 months (range, 0.4 to 21 months), 26% of patients were female, 59% had coronary artery bypass graft procedures, 36% had aortic valve procedures, and 25% had mitral valve procedures. SR without AADs at 6, 12, and 24 months was 82% (79 of 96), 87% (78 of 90), and 79% (61 of 77), respectively. The only independent predictor of SR without AADs at 6 months was smaller LA size (odds ratio, 0.35; p = 0.014). Return to SR without AADs at 6, 12, and 24 months was as follows: 92%, 93%, and 91%, respectively, for patients with no traditional predictors of failure (n = 32); 88%, 90%, and 77%, respectively, for one predictor (n = 47); and 66%, 76%, and 70% for two or more predictors (n = 31).

CONCLUSIONS: LA-only ablation yielded acceptable success rates, primarily in patients with shorter AF duration and smaller LA. However, success was reduced in patients with traditional predictors of failure. Well-designed studies with standardized lesion sets and ablation tools are required to determine whether full Cox maze yields better outcomes in patients with more advanced AF.