Characterization of Preoperative Cardiac Function and Atrial Fibrillation
Overall, 4% (7/174) of patients had a history of myocardial infarction, while 85% (148/174) had some degree of congestive heart failure symptoms associated with their AF (table 2). Mean left ventricular ejection fraction was 54±13%, and 41% (72/174) of patients had New York Heart Association Class III or IV heart failure.[29] There were no significant differences between groups by rhythm outcome for any of these variables.
Overall median length of time in AF was 7.8 years (IQR 4.0-12.0 years), and mean left atrial diameter was 4.8±1.0 cm. The majority of patients (71%, 124/174) had failed at least one prior catheter-based ablation attempt, with a median number of failed attempts of 2 (IQR 1-3). None of these variables varied significantly between groups by rhythm outcome. Patients who remained ATA-recurrence free over the follow-up period did have a significantly lower rate of preoperative pacemaker or implantable cardioverter defibrillator placement (6% versus 22%, p =0.0095) compared to those who had an ATA recurrence.