Despite a considerable improvement in TAVR devices and procedures, together with a reduction in procedural complications, the rate of conduction disturbances (CD) remained stable over the years. Indeed, the CD rate is still significantly higher than in surgical aortic valve replacement, and represents one of the main limitations to the expansion of TAVR to younger low-risk patients. The aim of the present study was to assess the incidence and predictors of CD in low-risk patients undergoing TAVR. Among 637 patients without preexisting CD who underwent TAVR, 116 (18.2%) were considered at low surgical risk. Up to 25% of low-risk patients presented with persistent CD at discharge. The pacemaker implantation rate was similar in the low-risk group compared to the intermediate-/high-risk group (8.7% vs 10.6%, p = 0.55). Moreover, the rate of new persistent left bundle branch block (LBBB) following TAVR was also similar between both groups (18.1% vs 22.1%, p = 0.34). At 1-year follow-up, LBBB was persistent in 62.5% of patients and 3 of them required a pacemaker implantation. Depth of valve implantation, baseline QRS duration and mean aortic transvalvular gradient were identified as independent predictors of CD in low-risk patients. Patients at low surgical risk showed an equivalent CD rate than intermediate-/high-risk patients. The depth of valve implantation was the main predictor of CD in low-risk patients undergoing TAVR. Baseline QRS duration and mean aortic transvalvular gradient were also associated with increased CD.
Keywords: Conduction disturbances; LBBB; Pacemaker; TAVR.