New-Onset Left Bundle Branch Block After TAVI has a Deleterious Impact on Left Ventricular Systolic Function

Background: Transcatheter aortic valve implantation (TAVI) has revolutionized the management of severe aortic stenosis. The development of a new-onset complete left bundle branch block (LBBB) is, however, a frequent complication. The objective of the present study was to assess the impact of a new-onset LBBB after TAVI on the evolution of left ventricular ejection fraction (LVEF). Methods: Forty consecutive patients were included after the development of a new-onset LBBB after TAVI and were matched for age and LVEF with 40 patients implanted during the same period who did not develop an LBBB. The primary endpoint was evolution of the LVEF measured by echocardiography before implantation and between 6 and 12 months after TAVI. Results: The development of an LBBB was associated with a 5-point decrease in LVEF [-12.5; 2.5], contrary to the non-LBBB group (1.5 [-6.5; 9.5], P = 0.007) at 8 months, with the persistence of the LBBB (n = 23) exacerbating this decrease (-7 [-13; 2], P = 0.009). When left ventricular dysfunction (LVEF < 50%) was present before TAVI, the appearance of an LBBB was associated with a reduction in LVEF (-2 [-8; 2]) contrary to the non-LBBB group (20 [9; 22], P = 0.02). Conclusions: The appearance of a new-onset LBBB after TAVI has a pejorative impact on left ventricular systolic function, particularly in patients with an initial LVEF < 50%, due to a lack of recovery of the latter, thereby potentially affecting their prognosis.