Incidence, Predictors, and Prognostic Impact of Left Ventricular Outflow Tract Obstruction Following Transcatheter Aortic Valve Replacement

Abstract

Background

Dynamic left ventricular outflow tract obstruction (LVOTO) following transcatheter aortic valve replacement (TAVR) is a potential complication that can cause severe hemodynamic instability. However, limited evidence is available regarding the incidence and predictors of LVOTO post-TAVR. This study aimed to clarify the incidence and identify the predictors of LVOTO following TAVR and to investigate whether LVOTO is associated with clinical outcomes.

Methods

This retrospective, single-centre study analyzed 2068 consecutive patients with aortic stenosis who underwent TAVR between January 2014 and December 2023. Transthoracic echocardiography was performed both before and after TAVR. LVOTO was defined as a peak pressure gradient exceeding 30 mm Hg.

Results

LVOTO occurred in 25 of 1963 patients (1.3%), with 6 patients developing acute hemodynamic compromise immediately after TAVR. Least absolute shrinkage and selection operator-penalized regression analysis identified the left ventricular outflow tract dimension (LVOTD), interventricular septum (IVS) thickness, transvalvular velocity, LVOT maximum velocity (V_max), and aortic annulus-to-LVOT area ratio (A/L ratio) as independent predictors of LVOTO following TAVR. Kaplan-Meier analysis revealed no association between LVOTO following TAVR and all-cause mortality or rehospitalization for heart failure.

Conclusions

The incidence of LVOTO after TAVR was 1.27%. Predictors of LVOTO were the IVS thickness, transvalvular velocity, LVOTD, LVOT V_max, and A/L ratio. Notably, LVOTO following TAVR was not associated with the composite outcome of all-cause mortality or heart failure hospitalization.