Left Atrial Appendage Exclusion in Atrial Fibrillation Radiofrequency Ablation during Mitral Valve Surgery: A Single-Center Experience

Abstract

Background. Atrial fibrillation surgical radiofrequency ablation (AFSA) during mitral valve surgery (MVS) has almost completely superseded the Cox-Maze procedure for the treatment of atrial fibrillation. Methods. We retrospectively analyzed 100 patients who underwent MVS + AFSA in our institution from January 2008 to June 2017. We compared the effectiveness of AFSA in patients who underwent LAA exclusion to those who did not. Moreover, we analyzed the role of preoperative AF duration (≤ or >1 year) and medial-lateral left atrial dimensions (ML-LAD) (≤ or >6 cm). The efficacy endpoint was freedom from AF at discharge and at 2-year follow-up. The safety endpoints were need of a permanent pacemaker (PMK), surgical re-exploration, occurrence of stroke, and left circumflex artery or esophageal lesions. Results. Overall, the rate of AF freedom was 69% at discharge and 80% at 2-year follow-up. LAA exclusion did not influence AF freedom at 2-year follow-up, and 84.6% of patients who underwent LAA exclusion were in the sinus rythm (SR) at 2 year compared to 75% of those who did not receive LAA exclusion free from AF as well ( $p=0.230$ ). AF duration ≤1 or >1 year did not influence sinus rhythm (SR) maintenance (85.7% vs. 75.8%; $p=0.224$ ), and in these two groups, LAA exclusion did not change the efficacy of AFSA. ML-LAD ≤ 6 cm was associated with better results in terms of SR maintenance. A statistically significant association between LAA exclusion and SR maintenance at 2-year follow-up ( $p=0.017$ ) was found among patients with ML-LAD ≤ 6 cm. Complications included 7 cases of PMK implantation, 2 cases of surgical re-exploration, and 1 case of stroke. No circumflex artery or esophageal lesions occurred after surgical procedures. Conclusions. In our experience, AFSA during isolated MVS resulted in good outcomes in terms of SR maintenance and incidence of complications. AF duration ≤ 1 year did not influence results, while patients with ML-LAD ≤ 6 cm had significantly better results regarding SR at follow-up. In patients with ML-LAD ≤ 6 cm, LAA exclusion significantly increased the success rate of SR maintenance at 2-year follow-up.