The impact of valvuloarterial impedance on left ventricular geometrical change after transcatheter aortic valve replacement: A comparison between valvuloarterial impedance and mean pressure gradient

Abstract

Increase in left ventricular (LV) mass develops as a compensatory mechanism against pressure overload in aortic valve stenosis. However, long-standing LV geometrical changes are related to poor prognosis. The LV geometrical change occurs after transcatheter aortic valve replacement (TAVR). The present study aimed to investigate the relationship between improvement in valvuloarterial impedance (Zva) and change in LV mass index (LVMI) and the ratio of LVMI to LV end-diastolic volume index (LVMI/LVEDVI). We compared these relationships to that between Zva and mean pressure gradient (MPG). Baseline and follow-up transthoracic echocardiograms of 301 patients who underwent TAVR from November 2011 to December 2015 were reviewed. Spearman correlation coefficient (ρ) was used to compare ∆LVMI and ∆LVMI/LVEDVI with Zva or MPG. The correlation between ∆Zva and ∆LVMI (ρ = 0.47, p < 0.001) was superior to that between ∆MPG and ∆LVMI (ρ = 0.15, p = 0.009) (p for comparison < 0.001). The correlation between ∆Zva and ∆LVMI/LVEDVI was statistically significant (ρ = 0.54, p < 0.001); in contrast, that of ∆MPG and ∆LVMI/LVEDVI was not. The improvement in Zva after TAVR was more closely related to LVMI and LVMI/LVEDVI reduction than MPG reduction.