6
Aortic Stenosis
Table 9. Stages of Valvular AS
Stage Definition Valve Anatomy
A At risk of AS • Bicuspid aortic valve (or other
congenital valve anomaly)
• Aortic valve sclerosis
B Progressive AS • Mild-to-moderate leaflet
calcification of a bicuspid
or trileaflet valve with some
reduction in systolic motion or
• Rheumatic valve changes with
commissural fusion
C: Asymptomatic severe AS
C1 Asymptomatic severe AS Severe leaflet calcification or
congenital stenosis with severely
reduced leaflet opening
C2 Asymptomatic severe AS with LV
dysfunction
Severe leaflet calcification or
congenital stenosis with severely
reduced leaflet opening
D: Symptomatic severe AS
D1 Symptomatic severe high-
gradient AS
Severe leaflet calcification or
congenital stenosis with severely
reduced leaflet opening
D2 Symptomatic severe low-flow/low-
gradient AS with reduced LVEF
Severe leaflet calcification with
severely reduced leaflet motion
D3 Symptomatic severe low-gradient
AS with normal LVEF or
paradoxical low-flow severe AS
Severe leaflet calcification with
severely reduced leaflet motion
