- native aortic valve leaflet thickening with reduced systolic opening on two-dimensional echocardiography and an aortic jet velocity at rest between 2.8 and 3.1 m/s or a valve area calculated by the continuity equation of 1.7 to 1.5 cm2, evaluated at a heart rate between 60 and 90/ minute and at a systolic arterial pressure of 120-140mmHg at baseline;