Impact of left bundle branch block after transcatheter aortic valve replacement

• Four major studies have investigated the outcome of LBBB after TAVR.
• The result has been divergent and, therefore, it is too soon to draw any conclusions.
• More strict LBBB criteria, validation of left wall dyssynchrony using other modalities and longer follow up are needed.

The number of patients with severe aortic stenosis getting treated with transcatheter aortic valve replacement (TAVR) is rapidly growing and the outcome after the procedure is very good. However, the incidence of new persistent left bundle branch block (LBBB) following the TAVR procedure is high and the impact of this new conduction disturbance has been studied in four major studies with divergent result. This review investigates the differences between these studies that might explain the divergent results and concludes that future studies are needed to characterize whether or not new LBBB after TAVR fulfills the new strict LBBB criteria, whether these new LBBB patients develops left ventricular dyssynchrony, and which, if any, might benefit from cardiac resyncronization therapy (CRT).