3.5. Recurrence of AF after 12-month follow-up
 Two single-center RCTs22,23 indicated comparable results in AF recurrence during 12-month follow-up after the concomitant Cox-Maze and PVI, while the CTSN trial clearly demonstrated higher risk of AF recurrence after the concomitant PVI procedure during MV surgery (Table 1).21 However,  CI/CrI (from 3-4-fold lower to 3-4-fold higher risk after PVI) and prediction intervals around the pooled estimates were very wide (Figure 2B) illustrating uncertainty when comparing 12-month recurrence of AF among patients who underwent Cox-Maze and PVI. However, Srivastava and colleagues excluded patients with enlarged left atrium (>6 cm) or if they received antiarrhythmic drugs preoperatively from their RCT, which are actually subsets of patients that would benefit most from Cox-Maze procedure23.
Adjusted recurrence of AF at 12 months appeared comparable in a study by Gillinov and colleagues (PVI 11% vs. Cox-Maze 8%), although patients who underwent PVI had significantly shorter duration of preoperative AF (Table 1) [18]. AF recurrence was significantly higher among patients who underwent PVI in the study by Onorati and colleagues (adjusted estimates PVI 35% vs. Cox-Maze 17%, risk ratio=2.13, 95%CI 1.10-3.94) (Table 1) 25. Among additional reported outcomes, the authors also demonstrated higher adjusted recurrence of AF at 6 months, higher adjusted proportion of antiarrhythmics at 12 months, and higher adjusted risk of death or hospitalization among patients who underwent PVI 25. Furthermore, in the study of 324 patients who underwent isolated MV surgery, Stulak and colleagues reported significantly higher recurrence of AF after 12-month follow-up among patients who underwent concomitant PVI (30% vs. 13% Cox-Maze)24.