Outcomes in patients with electrocardiographic left ventricular dyssynchrony following transcatheter aortic valve replacement

BACKGROUND Left bundle branch block (LBBB) and atrioventric-ular (AV) conduction abnormalities requiring permanent pacemaker (PPM) implantation occur frequently following transcatheter aortic valve replacement (TAVR). The resultant left ventricular (LV) dys-synchrony may be associated with adverse clinical events. OBJECTIVES The purpose of this study was to assess the adverse outcomes associated with LV dyssynchrony due to high-burden right ventricular (RV) pacing or permanent LBBB following TAVR in pa-tients with preserved left ventricular ejection fraction (LVEF). METHODS Consecutive TAVR patients at the University of Michigan from January 2012 to June 2017 were included. Pre-existing cardiac implantable electronic device, previous LBBB, LVEF <50%, or follow-up period <1 year were excluded. The primary outcome was all-cause mortality. Secondary outcomes included cardiomyop-athy (defined as LVEF <45%), a composite endpoint of cardiomyop-athy or all-cause mortality, and the change in LVEF at 1-year follow-up. RESULTS A total of 362 patients were analyzed (mean age 77 years). LV dyssynchrony group (n = 91 [25.1%]) included 56 perma-nent LBBB patients, 12 permanent LBBB patients with PPM, and 23 non-LBBB patients with PPM and high-burden RV pacing. Remaining patients served as control (n = 271 [74.9%]). After adjusted anal-ysis, LV dyssynchrony had significantly higher all-cause mortality (adjusted hazard ratio [HR] 2.16; 95% confidence interval [CI] 1.07-4.37) and cardiomyopathy (adjusted HR 14.80; 95% CI 6.31-14.69). The LV dyssynchrony group had mean LVEF decline of 10.5% +/- 10.2% compared to a small increase (0.5% +/- 7.7%) in control. CONCLUSION Among TAVR patients with preserved LVEF and normal AV conduction, development of postprocedural LV dyssyn-chrony secondary to high-burden RV pacing or permanent LBBB was associated with significantly higher risk of death and cardiomy-opathy at 1-year follow-up.