Background: We sought to investigate the hemodynamic impact of increased systemic arterial compliance (SAC) in patients with aortic stenosis (AS) requiring valve replacement (AVR). Methods: The study cohort includes 453 consecutive patients (247 males; mean age, 63.9짹10.9 years). Besides, SAC (stroke volume index [SVi]/pulse pressure), an index of valvular-arterial impedence was calculated ([systolic arterial pressure+transvalvular pressure gradient at pressure recovery]/SVi, Z_VA). In patients with normal LVEF (EF���50%, n=362), low flow AS was defined as SVi<22 ml/m^2.04. Results: In all patients, Z_VA showed stronger correlation (r=0.601) with pre-AVR LV mass index/LV end-diastolic volume index (LVMI/LVEDVI) than conventional markers of hemodynamic severity including aortic valve area (AVA, r=0.061), maximal velocity (Vmax, r=0.211) and mean pressure gradient (PG, r=0.194). Low flow AS was diagnosed in 203 patients (56.1%) and, despite similar AVA, Vmax and PG, they showed higher mean age, higher prevalence of female gender, smaller body surface area, higher LVMI/LVEDVI, lower SAC, and higher Z_VA than those with normal flow AS. Conclusions: AS is not an isolated disease strictly limited to the aortic valve but often rather a systemic disease entity often including increased rigidity of the aorta.