Impact of Valvuloarterial Impedance on Concentric Remodeling in Aortic Stenosis and Its Regression after Valve Replacement

J Cardiovasc Ultrasound. 2016 Sep;24(3):201-207. doi: 10.4250/jcu.2016.24.3.201. Epub 2016 Sep 26.

Abstract

Background: Left ventricle (LV) in patients with aortic stenosis (AS) faces a double hemodynamic load incorporating both valvular stenosis and reduced systemic arterial compliance (SAC). This study aimed to evaluate the impact of global LV afterload on LV hypertrophy (LVH) before and after aortic valve replacement (AVR).

Methods: The study cohort included 453 patients (247 males; mean age, 64 ± 11 years) who underwent AVR. Pre- and post-AVR echocardiographic examinations were retrospectively analyzed including an index of valvuloarterial impedance (ZVA) and LV mass index/LV end-diastolic volume index (LVMI/LVEDVI) as a parameter of LVH.

Results: Pre-AVR LVMI/LVEDVI was 2.7 ± 0.9 g/mL with an aortic valve area (AVA) of 0.6 ± 0.2 cm2. ZVA was 5.9 ± 1.9 mm Hg/mL/m2 and showed a stronger correlation (β = 0.601, p < 0.001) with pre-AVR LVMI/LVEDVI than indexed AVA (β = 0.061, p = 0.19), transvalvular peak velocity (β = 0.211, p < 0.001). During a median follow-up of 3.5 years, patients had a 18.8 ± 10.4% decrease in the LV geometry index with a decrease in SAC from 1.20 ± 0.48 to 1.00 ± 0.38 mL/m2/mm Hg (p < 0.001). Pre-AVR LV ejection fraction (r = 0.284, p < 0.001) and ZVA (r = 0.523, p < 0.001) were independent factors associated with LVH regression in 322 patients with follow-up duration >1 year after AVR.

Conclusion: ZVA is a major determinant of concentric remodeling in AS before AVR and LVH regression after AVR, which should be incorporated in routine evaluation of AS.

Keywords: Afterload; Aortic stenosis; Echocardiography; Left ventricular hypertrophy.