RESUMO
INTRODUCTION: Mitral valve surgery has developed into a strong subspecialty of cardiac surgery with operative techniques and outcomes constantly improving. The development of bradyarrhythmias after mitral valve surgery is not completely understood. METHODS: We investigated a cohort of 797 patients requiring mitral valve surgery with and without concomitant procedures. Incidences and predictors of pacemaker requirement as well as survival were analyzed. RESULTS: In the complete follow-up period (median follow-up time: 6.09 years [95% confidence interval [CI]: 5.94-6.22 years, maximum 8.77 years) 80 patients (10% of the complete cohort) required pacemaker implantation for bradyarrhythmia. The cumulative rate of pacemaker implantation was 6.4% at 50 days (48 patients) with most (54.2%) requiring pacing for atrioventricular block. Mitral valve replacement (odds ratio [OR]: 1.905; 95% CI: 1.206-3.536; p = .041) and tricuspid ring annuloplasty (OR: 2.348; 95% CI: 1.165-4.730, p = .017) were identified as operative risk factors of pacemaker requirement after mitral valve surgery. Insulin-dependent diabetes mellitus was also identified as a predictor of pacemaker requirement (OR: 4.665; 95% CI: 1.975-11.02; p = .001). There was no difference in survival in the paced and unpaced groups. CONCLUSIONS: After mitral valve surgery, a relevant subgroup of patients requires pacemaker implantation-most for atrioventricular block. We identified mitral valve replacement and tricuspid ring annuloplasty as significant operative risk factors and insulin-dependent diabetes mellitus as a demographic risk factor. While anatomic relationships help explain the operative risk factors the role of diabetes mellitus is not completely understood.