Outcomes of Left Atrial Ablation in Patients with Prior Mitral Valve Surgery

Background: Patients with a history of mitral valve (MV) surgery can present with unique challenges during left atrial (LA) ablation due to abnormal atrial substrate and descriptions of ablation in this cohort is limited. We aim to evaluate LA ablation characteristics and outcomes in patients with a history of mitral valve surgery. Objective: We hypothesize that the success rate for ablations of LA arrhythmias in patients with prior MV surgery will be inferior to patients without prior MV surgery due to left atriopathy, presence of a MV prosthesis, and a higher burden of pre-ablation LA scar. Methods: In this single center, retrospective study, we evaluated patients who had a history of MV surgery and underwent LA ablation between January 2013 and May 2019. We analyzed baseline patient characteristics, type of MV disease and surgery, available pre-ablation voltage maps, and ablation outcomes. Results: We present a series of 20 patients who underwent a total of 30 LA ablation procedures. All 20 patients underwent pulmonary vein isolation and 11 patients also underwent ablation for LA macro-reentrant flutters. The majority of the patients (55%) were without recurrent documented arrhythmias at a mean follow-up of 22 months post-ablation. Two patients had acutely unsuccessful ablation. Conclusions: Although LA ablation in patients with previous MV surgery can be challenging due to abnormal atrial substrate and the presence of the valve prosthesis, the majority of patients in our cohort experienced atrial arrhythmia free survival at a mean follow-up of 22 months.