6117Persistent LBBB and AV block with high-burden RV pacing following transcatheter aortic valve replacement are associated with new onset cardiomyopathy

Abstract

Abstract Background Left bundle branch block (LBBB) and AV nodal block (AVB) requiring permanent pacemaker implantation occur frequently following transcatheter aortic valve replacement (TAVR) and may be associated with adverse clinical events. Objectives The study aims to assess the incidence of new onset cardiomyopathy among patients with normal left ventricular systolic function patients who developed LBBB or persistent AVB with high-burden right ventricular (RV) pacing (>80%) following TAVR procedure. Methods Consecutive patients who underwent TAVR procedure from January 2012 to June 2017 at the University of Michigan Health System were included in the retrospective analysis. Those who had a preexisting cardiac implantable electronic device (CIED), prior LBBB, left ventricular ejection fraction (LVEF) <50%, and follow up period less than 1 year were excluded from this analysis. New onset cardiomyopathy was defined by a left ventricular ejection fraction (LVEF) <45% within 1 year after TAVR. Results A total of 362 patients were included in the study (mean age 76.9±11.5 years, 56.1% male). Of these, 30 patients (8.3%) developed persistent AVB and required >80% RV pacing (pacing group), 61 patients (16.9%) developed persistent LBBB (LBBB group), and 271 patients (74.9%) did not have LBBB or AVB or required <80% RV pacing (control group). Baseline LVEF was 63.9+6.4% in pacing group (p=0.76) and 64.4+7.4% in LBBB group (p=0.89) compared to 64.3+6.5% in control group. Within 1 year after TAVR, 10/30 patients (33.3%) in pacing group (p<0.01) and 20/61 patients (32.8%) in LBBB (p<0.01) developed new onset cardiomyopathy compared to 9/271 patients (3.3%) in control group. LVEF at 1 year was 53.8+11.9% in pacing group (p<0.01) and 53.7+12.1% in LBBB group (p<0.01) compared to 64.8+7.7% in control group. Conclusion Among patients with normal baseline left ventricular systolic function, AV block required high-burden RV pacing and persistent LBBB following TAVR were associated with significantly higher incidence of new onset cardiomyopathy.