Predictors and prognostic impact of new left bundle branch block after surgical aortic valve replacement

Summary Background Left bundle branch block (LBBB) induces mechanical dyssynchrony that may lead to left ventricular systolic dysfunction. Aims To evaluate the incidence, predictors and clinical impact of new LBBB in patients undergoing surgical aortic valve replacement (SAVR). Methods After exclusion of patients with pre-existing LBBB, a previous pacemaker or a paced rhythm at hospital discharge, 547 consecutive patients undergoing SAVR were included. All-cause death, cardiovascular death and the combined outcome of all-cause death or a first heart failure event were assessed at 3 months and 1 year. Patients with and without new LBBB were compared. Results New LBBB occurred in 4.6% of patients after SAVR (compared with 16.4% of patients treated by transcatheter aortic valve implantation during the study period). Previous valve surgery and an immediate postoperative paced rhythm were independent predictors of new LBBB. At 1-year follow-up, there were no significant differences in all-cause death, cardiovascular death, or the combined outcome of all-cause death or a first heart failure event between patients with and without new LBBB. However, new LBBB was associated with a trend towards functional deterioration and more heart failure events at 1 year. Conclusion At 1-year follow-up, new LBBB did not have a significant impact on clinical outcome, but was associated with worse functional status and more heart failure events.