In aortic valve regurgitation (AR), aortic leak severity modulates left ventricle (LV) arterial system interaction. The aim of this study was to assess (1) how arterial elastance (E(a)), calculated as the ratio of LV end-systolic pressure and stroke volume, relates to arterial properties and leak severity and (2) the validity of E(a)/E(max) (with E(max) the slope of the end-systolic pressure-volume relation) as a heart-arterial coupling parameter in AR.