The Association Between Newly Acquired Permanent Left Bundle Branch Block Following Transcatheter Aortic Valve...

Left bundle branch block (LBBB) frequently occurs after transcatheter aortic valve replacement (TAVR) and may lead to adverse clinical outcomes.

This study assesses the incidence of new-onset cardiomyopathy in patients with normal left ventricular systolic function who develop permanent LBBB post-TAVR.

We performed a retrospective analysis of consecutive TAVR patients at the University of Michigan Health System from January 2012 to June 2017. Exclusions included patients with pre-existing cardiac implantable devices, LBBB, right bundle branch block (RBBB), left ventricular ejection fraction (LVEF) < 50%, those requiring new permanent pacemakers, or with less than 1 year of follow-up. The primary outcome was new-onset cardiomyopathy (LVEF < 45% at 1 year), with secondary outcomes including all-cause mortality and changes in LVEF.

A total of 273 patients were included (mean age 76.5 years; 47.6% female). Of these, 69 (25.3%) developed new-onset permanent LBBB. At 1 year, 27.5% of the LBBB group developed cardiomyopathy, compared to 2.0% in the control group (p < 0.01). The LVEF was significantly lower in the LBBB group (55.7% vs. 65.3%, p < 0.01). The composite endpoint of new-onset cardiomyopathy and mortality was higher in the LBBB group (39.1% vs. 10.3%, p < 0.01).

Newly acquired permanent LBBB post-TAVR is associated with a significantly higher incidence of new-onset cardiomyopathy in patients with normal baseline LVEF.