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

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 3months and 1year. 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 1year.
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.
(Copyright © 2017. Published by Elsevier Masson SAS.)