Safety and Efficacy of Biatrial vs. Left Atrial Surgical Ablation During Concomitant Cardiac Surgery: A Meta-Analysis of Clinical Studies With a Focus on the Causes of Pacemaker Implantation.

INTRODUCTION: The latest STS guidelines recommend concomitant atrial fibrillation (AF) ablation not only during mitral surgery (Class IA) but also during other-than-mitral cardiac surgery procedures (Class IB) in patients with preoperative AF. Conventional Cox-Maze III/IV procedures are performed on both atria (BA), but several studies reported excellent results with left atrial only (LA) ablations: the scope of this study is to compare the safety and efficacy of BA vs LA approach. METHODS AND RESULTS: Pubmed, Scopus, and WOS were searched from inception to November 2018: 28 studies including 7065 patients and comparing the performance of BA vs LA approaches were identified: of these, 16 (57.1%) enrolled exclusively patients with non-paroxysmal AF forms, 10 (35.7%) focused on mitral surgery as main procedure, and 16 (57.1%) regarded patients undergone Cox-Maze with radiofrequency. The 6- and 12-months prevalence of sinus rhythm were higher in the BA group (OR, 1.37, CI, 1.09-1.73, P = .008 and OR, 1.37, CI, 0.99-1.88, P = .05 respectively). Permanent pacemaker (PPM) implantation (OR, 1.85, CI, 1.38-2.49, P < .0001) and reopening for bleeding (OR, 1.70, CI, 1.05-2.75, P = .03) were higher in the BA group. Among patients undergone PPM implantation, BA group had a significantly higher risk of sinoatrial node dysfunction (OR, 3.01, CI, 1.49-6.07, P = .002). CONCLUSIONS: Concomitant BA ablation appears superior to LA ablation in terms of efficacy but is associated with a higher risk of bleeding and of PPM implantation, more frequently due to sinoatrial node dysfunction. LA approach should be preferable in patients with a higher risk of bleeding or with perioperative risk factors for PPM implantation.