Persistent conduction abnormalities and requirements for pacemaking six months after transcatheter aortic valve implantation

Abstract

Early conduction abnormalities and need for pacemaking after transcatheter aortic valve implantation (TAVI) is well recognised. It is still unknown, however, if these conduction abnormalities are persistent, and what is the need for permanent pacemaking after 1-month follow-up. In this prospective study, we examined the incidence of post-procedural and 6-month conduction abnormalities and need for permanent pacemaking after TAVI. We examined the 12-lead electrocardiogram (ECG) of 91 consecutive patients in whom a Medtronic CoreValve ReValving System was implanted between November 2005 and April 2009. We evaluated the ECGs before treatment, after treatment, at 1-month and 6-month follow-up. The requirement and timing of permanent pacemaking was documented. The mean age of patients was 81±7 years and the mean logistic EuroSCORE was 16±9%. Median duration of follow-up was 213 days (IQR 64, 519). There was a 39% increase in the frequency of LBBB after TAVI (15% before treatment vs. 54% after treatment, p<0.001). Importantly, there was no significant change in the frequency of LBBB from after treatment to 1- or 6-month follow-up (54% after treatment vs. 42% at 1-month follow-up, p=0.45, and 54% after treatment vs. 45% at 6-month follow-up, p=0.39). Permanent pacemaking was required in 17/91 (19%) of patients. A permanent pacemaker was implanted in 8/17 patients (47%) within seven days of TAVI, in 6/17 (35%) at 7-30 days, and in 3/17 (18%) after 30 days. Male gender, previous myocardial infarction, pre-existing right bundle branch block, actual diameter (mm) of the inflow portion of the CoreValve frame post-implantation and depth of implantation were predictors for new LBBB; pre-treatment QRS duration (msec) and septal wall thickness were predictors for permanent pacemaking. These results suggest that early conduction abnormalities occurring after TAVI persist at 6-months follow-up. Patient-related, anatomical-related, and procedure-related factors need to be considered in the pathogenesis of conduction abnormalities after TAVI.