Risk Factors of Recurrence of Atrial Fibrillation (AF) After AF Surgery in Patients With AF and Mitral Valve Disease

The purpose of this study was to determine the 22-year experience of the relationship between preoperative left atrial diameter (LAD) and atrial fibrillation (AF) recurrence after AF surgery. Between November 1993 and April 2015, 244 patients underwent AF surgery concomitant with mitral valve surgery, and were completely followed up in our institute. The full-maze procedure was performed in 231 patients and pulmonary vein isolation in 13. Three quartiles divided the list of sorted LAD data into 4 groups: group Q1: LAD = 40.5 ± 4.3 (n = 55), group Q2: LAD = 47.9 ± 2.0 (n = 61), group Q3: LAD = 54.2 ± 1.6 (n = 66), and group Q4: LAD = 64.2 ± 5.6 (n = 62). The AF cure rates for 22 years were verified between the groups. Although the AF cure rate of the full-maze procedure was 94%, 80%, 63%, and 51% at 1, 5, 10, and 20 years after AF surgery, respectively, it was 100% at 5 and 10 years after the pulmonary vein isolation (P = 0.088). Although there were no significant differences in the AF cure rate between groups Q1-Q3, the AF cure rate was significantly lower in group Q4 than the other groups (P < 0.001). A multivariate Cox proportional hazard model revealed that the preoperative LAD and cardiothoracic ratio were significant risk factors of AF recurrence (hazard ratio 1.063 per 1-mm increase, P = 0.003, and hazard ratio 1.064 per 1% increase, P = 0.043, respectively). AF surgery was effective for 22 years after surgery for AF concomitant with mitral valve disease. A preoperative LAD of ≥58.0 mm and the cardiothoracic ratio were risk factors of AF recurrence after AF surgery.