Outcomes of Patients With New Left Bundle Branch Block After TAVR: TVT Registry Insights

BACKGROUND: Cardiac conduction disturbances remain the most frequent complication of transcatheter aortic valve replacement (TAVR), but the clinical implications of new left bundle branch block (LBBB) after TAVR remain controversial. Here, we aim to assess the impact of new LBBB after TAVR on patient outcomes in a large, real-world registry. METHODS: The study population consisted of patients in the TVT registry (Society of Thoracic Surgery and American College of Cardiology Transcatheter Valve Therapy Registry) who underwent TAVR for aortic stenosis between 2016 and 2022 and were discharged alive from the index hospitalization. Key exclusion criteria included preexisting conduction defects and a permanent pacemaker before TAVR or during the index hospitalization. Clinical outcomes were compared between patients with and without new LBBB using Cox proportional hazards models adjusted for baseline demographic, clinical, and echocardiographic variables. RESULTS: Among 202 533 TAVR recipients, 32 933 (16.3%) developed new LBBB after TAVR. Over the study period, there was a significant decrease in the incidence of new LBBB from 19.9% in the first quarter of 2016 to 14.4% in the third quarter of 2022. Patients with new LBBB after TAVR, compared with those without LBBB, had significantly greater 1-year all-cause mortality (adjusted hazard ratio, 1.19 [95% CI, 1.13–1.25]; P <0.001), hospital readmission (adjusted hazard ratio, 1.23 [95% CI, 1.19–1.28]; P <0.001), and new pacemaker requirement (adjusted hazard ratio, 3.50 [95% CI, 3.26–3.76]; P <0.001). Patients with new LBBB also had lower Kansas City Cardiomyopathy Questionnaire Overall Summary scores (adjusted difference, −1.7 points [95% CI, −2.1 to −1.3]; P <0.001) and left ventricular ejection fraction (adjusted difference, −2.8% [95% CI, −3.4% to −2.2%]; P <0.001). CONCLUSIONS: New LBBB after TAVR is associated with worse 1-year outcomes, including death, rehospitalization, and permanent pacemaker, as well as worse health status and lower left ventricular ejection fraction. These findings suggest that continued efforts to limit the development of conduction disturbance after TAVR are warranted.