Background: Atrial fibrillation (AF) is present in up to a third of patients referred for mitral valve surgery (MVS), and represents the most common indication for surgical ablation (SA). Preoperative AF has a significant impact on late survival following MVS. While the majority of SA are performed in MVS patients, there are few studies examining long-term freedom from atrial tachyarrhythmias (ATAs).
Objective: This study examined our late outcomes following concomitant CMP-IV and MVS.
Methods: Between January 2003 and May 2019, 365 patients underwent concomitant CMP-IV and MVS. Cox-Maze III procedures or other SA techniques that did not completely isolate the posterior left atrium (LA) were excluded (n=25). The remaining patients underwent either biatrial CMP-IV (n=297) or left-sided Cox-Maze (n=43). The majority of patients received MV repair (64%, 218/340). Freedom from ATAs was determined by ECG, Holter, or pacemaker interrogation at 1 year and annually thereafter. Mean follow-up was 3.2 ± 1.9 years, and 86% (292/340) of patients underwent prolonged monitoring. Recurrence was defined as any documented ATAs lasting ≥30 seconds. Predictors of recurrence were determined by analyzing 30 variables using univariate and, if significant, multivariate logistic regression.
Results: The mean age was 64.6 ± 11.3 years, and the mean LA size was 5.8 ± 0.5 cm. The majority of patients (199/340, 59%) had non-paroxysmal AF. Ten percent of patients (33/340) had failed at least one catheter-based ablation. Thirty-day mortality was 3.5% (12/340) and overall major complication rate was 12.6% (43/340). Freedom from ATAs on or off antiarrhythmic drugs (AADs) was 94% (237/253) and 87% (219/253) at 1 year, respectively; 88% (157/179) and 77% (138/179) at 3 years; and 83% (105/126) and 68% (86/126) at 5 years. Being in AF at the time of hospital discharge, older age, longer cross-clamp time, and paroxysmal AF predicted recurrence at 5 years by multivariate analysis.
Conclusion: The CMP-IV was effective in restoring SR in patients undergoing concomitant MVS. At 5 years, over 80% of patients were free of recurrent ATAs. Presence of AF at time of hospital discharge and PVD were predictors of ATA recurrence at 5 years.