Risk Model for Predicting Complications in Patients Undergoing Atrial Fibrillation Ablation Short Title: Risk Score for Predicting Atrial Fibrillation Ablation Complications

Abstract Background Predictors of complications from AF ablation have been identified in small studies. The combination of risk factors to predict complications after ablation has not yet been explored. Objective To develop a risk score model that predicts complications after AF ablation. Methods The National Inpatient Sample database was utilized to identify 106,105 patients who underwent AF ablation. The study population was split into derivation cohort (DC, 2007-2010, n=56,658) and validation cohort (VC, 2011-2013, n=49,447). Multivariate predictors of any complication were identified in DC using regression analysis and a risk score model was developed. The cohorts were divided into 5-groups (risk score in parentheses): group 0 (0), 1 (1-10), 2 (11-20), 3 (21-30) and 4 (31-61). Results Patients in VC were older, likely to be white, female and had a higher prevalence of co-morbidities. The overall complication rate (6.9% vs. 8.3%, p Conclusions A practical risk score model can be used preoperatively to risk stratify patients undergoing AF ablation.