 There is long-term stability of the left ventricular hemodynamics after AVB, with no further biologic progression of native aortic valve stenosis.Once the pressure gradient across the native valve is substantially reduced, the narrowing and calcification of the native valve halts.In one study of 47 patients whose average age was 82 years, the mean gradient across the native valve was reduced from 46 +/- 14 mm HG to 17 +/- 7 mm HG.