In these patients, severe AS with LV systolic dysfunction attributable to afterload Table 13. Stages of AS Stage Definition Valve Anatomy Valve Hemodynamics Hemodynamic Consequences Symptoms A At risk of AS BAV (or other congenital valve anomaly) Aortic valve sclerosis Aortic Vmax <2 m/s with normal leaflet motion None None B Progressive AS Mild to moderate leaflet calcification/fibrosis of a bicuspid or trileaflet valve with some reduction in systolic motion or Rheumatic valve changes with commissural fusion Mild AS: aortic Vmax m/s or mean P <20 mm Hg Moderate AS: aortic Vmax 3.0 3.9 m/s or mean P 20 39 mm Hg Early LV diastolic dysfunction may be present Normal LVEF None C: Asymptomatic severe AS C1 Asymptomatic severe AS Severe leaflet calcification/ fibrosis or congenital stenosis with severely reduced leaflet opening Aortic Vmax 4 m/s or mean P 40 mm Hg AVA typically is 1.0 cm2 (or ) but not required to define severe AS Very severe AS is an aortic Vmax 5 m/s or mean P 60 mm Hg LV diastolic dysfunction Mild LV hypertrophy Normal LVEF None Exercise testing is reasonable to confirm symptom status C2 Asymptomatic severe AS with LV systolic dysfunction Severe leaflet calcification/ fibrosis or congenital stenosis with severely reduced leaflet opening Aortic Vmax 4 m/s or mean P 40 mm Hg (or ) but not required to define severe AS LVEF <50% None D: Symptomatic severe AS D1 Symptomatic severe high-gradient AS Severe leaflet calcification/ fibrosis or congenital stenosis with severely reduced leaflet opening Aortic Vmax 4 m/s or mean P 40 mm Hg (or ) but may be larger with mixed AS/AR LV diastolic dysfunction LV hypertrophy Pulmonary hypertension may be present Exertional dyspnea, decreased exercise tolerance, or HF Exertional angina Exertional syncope or presyncope D2 Symptomatic severe low-flow, low-gradient AS with reduced LVEF Severe leaflet calcification/ fibrosis with severely reduced leaflet motion with resting aortic Vmax <4 m/s or mean P <40 mm Hg Dobutamine stress echocardiography shows with Vmax m/s at any flow rate LV diastolic dysfunction LV hypertrophy HF Angina Syncope or presyncope D3 Symptomatic severe low-gradient AS with normal LVEF or paradoxical low-flow severe AS Severe leaflet calcification/ fibrosis with severely reduced leaflet motion (indexed AVA ) with an aortic Vmax <4 m/s or mean P <40 mm Hg AND Stroke volume index <35 Measured when patient is normotensive (systolic blood pressure <140 mm Hg) Increased LV relative wall thickness Small LV chamber with low stroke volume Restrictive diastolic filling HF Angina Syncope or presyncope AR indicates aortic regurgitation; AS, aortic stenosis; AVA, aortic valve area circulation; AVAi, AVA indexed to body surface area; BAV, bicuspid aortic valve; P, pressure gradient between the LV and aorta HF, heart failure; LV, left ventricular; LVEF, left ventricular ejection fraction; and Vmax , maximum velocity. 