The Need for Consistent Predictors of Success for Surgical Ablation of Atrial Fibrillation: A Call to Action

Objective: As with any medical therapy, identification of consistent and reliable outcome predictors is essential to understanding the efficacy of surgical ablation for atrial fibrillation. We originally intended to conduct a meta-analysis on atrial fibrillation surgical ablation to identify clinical factors that are most often associated with success. However, these studies are greatly heterogeneous. We conducted a systematic review to identify trends in outcome predictors and to provide recommendations for more uniform data analysis and reporting. Methods: Relevant studies published between January 2005 and September 2013 were identified. To minimize heterogeneity, data were extracted only from multivariate analyses of outcome predictors. The initial approach for meta-analytic analyses was abandoned for a systematic review approach. Results: From 604 initial citations, 19 studies with 5200 patients were included in the review. Systematic review of multivariable atrial fibrillation recurrence rates after surgical ablation revealed that studies were statistically heterogeneous, but atrial fibrillation recurrence after surgical ablation in mid-term follow-up was most often predicted by left atrium size, duration of atrial fibrillation, fine-wave atrial fibrillation, age of patient, and atrial fibrillation type. Conclusions: The innate heterogeneity of published data precludes a meta-analysis for predictors of surgical ablation success. Of the few published studies that allow comparison, the most consistent predictors of failure were enlarged left atrium and long atrial fibrillation duration. These results underscore the need for consistent and reliable outcome predictors. We strongly recommend the development of a standardized system of measurement for consistent clinical parameters that can be used in outcome analyses for surgical ablation of atrial fibrillation.