The chronic efficacy endpoint was a treatment success/failure measure for each subject computed at 6 months. Treatment success included: 1. A 90% reduction in clinically significant atrial fibrillation from baseline to the 6 month time point based on a Holter recording. Clinically significant atrial fibrillation was defined as sustained atrial fibrillation lasting more than 10 minutes. 2. The subject was off all antiarrhythmic drugs at 6 months (Ablation Management arm only) 3. The Investigator judged all procedures to be acutely successful (Ablation Management arm only).

The primary endpoint for acute safety was a success/failure variable calculated for each subject in Ablation Management at the 7 day post-procedure time point. Any subject with at least one adverse event adjudicated by the Data Safety Monitoring Board as both serious and either probably or definitely procedure and/or device-related occurring within 7 days of the ablation procedure was considered an acute safety failure, regardless of whether the event occurred following the index or retreatment ablation procedure.

The primary endpoint for chronic safety was a success/failure variable calculated for each subject at 6 months. Any subject that had at least one adverse event that met designated seriousness and relatedness criteria for the particular treatment group as adjudicated by the Data Safety Monitoring Board was considered a chronic safety failure. Adverse events in Ablation Management that were acute (≤7 days) were not included in the chronic safety primary endpoint. Given the disparity in the length of time at risk between treatment arms,the Chronic Safety endpoint was not statistically powered.