Clinical benefits of concomitant surgical ablation for atrial fibrillation in patients undergoing mitral valve surgery

Abstract

BACKGROUND The maze procedure is the dominant concomitant surgery performed with mitral valve (MV) surgery in patients with atrial fibrillation (AF). Most clinical recommendations regarding the maze procedure depend on the individual maze expert centers. OBJECTIVE The purpose of this study was to evaluate the clinical benefits of the maze procedure during MV surgery in a national cohort. METHODS Using the national health claims database established by the National Health Insurance Service of South Korea, data on subjects with AF who had undergone MV surgery from 2009 to 2017 were reviewed. The outcomes of interest were mortality; occurrence of ischemic or hemorrhagic stroke; hospitalization for bleeding events; and the composite of death, cerebrovascular accident, and major bleeding. Propensity score (PS) matching was per-formed for baseline adjustment. RESULTS Among 9501 subjects, the maze procedure was performed in 5508 (58.0%). In the PS-matched cohort (3376 pairs), the risk of the composite event was significantly lower in the maze group (hazard ratio [HR] 0.799; 95% confidence interval [CI] 0.731-0.873) than in the nonmaze group. The superiority of the maze procedure was similar for individual clinical events, including death (HR 0.795; 95% CI 0.711-0.889); ischemic stroke (HR 0.788; 95% CI 0.67-0.926); and major bleeding (HR 0.749; 95% CI 0.627-0.895), but not for hemorrhagic stroke (HR 0.984; 95% CI 0.768-1.262). In subgroup analyses of the composite events, these benefits were consistent among subjects aged >= 70 years or <70 years, surgery type (replacement vs repair), MV pathologies, and subjects with CHA(2)DS(2)-VASc score >= 4 or <4. CONCLUSION The addition of the maze procedure during MV sur-gery provided protective effects in the composite outcome of interest.