Table 6

Stages of Valvular AS

StageDefinitionValve AnatomyValve HemodynamicsHemodynamic ConsequencesSymptoms
AAt risk of AS
  • Bicuspid aortic valve (or other congenital valve anomaly)

  • Aortic valve sclerosis

  • Aortic Vmax <2 m/s

  • None

  • None

BProgressive 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

  • Mild AS:

    Aortic Vmax 2.0–2.9 m/s or

    mean ΔP <20 mm Hg

  • Moderate AS:

    Aortic Vmax 3.0–3.9 m/s or

    mean ΔP 20–39 mm Hg

  • Early LV diastolic dysfunction may be present

  • Normal LVEF

  • None

C: Asymptomatic severe AS
C1Asymptomatic severe AS
  • Severe leaflet calcification or congenital stenosis with severely reduced leaflet opening

  • Aortic Vmax ≥4 m/s or

    mean ΔP ≥40 mm Hg

  • AVA typically is ≤1.0 cm2 (or AVAi ≤0.6 cm2/m2)

  • Very severe AS is an aortic Vmax ≥5 m/s or mean ΔP ≥60 mm Hg

  • LV diastolic dysfunction

  • Mild LV hypertrophy

  • Normal LVEF

  • None: Exercise testing is reasonable to confirm symptom status

C2Asymptomatic severe AS with LV dysfunction
  • Severe leaflet calcification or congenital stenosis with severely reduced leaflet opening

  • Aortic Vmax ≥4 m/s or

    mean ΔP ≥40 mm Hg

  • AVA typically ≤1.0 cm2 (or AVAi ≤0.6 cm2/m2)

  • LVEF <50%

  • None

D: Symptomatic severe AS
D1Symptomatic severe high-gradient AS
  • Severe leaflet calcification or congenital stenosis with severely reduced leaflet opening

  • Aortic Vmax ≥4 m/s or

    mean ΔP ≥40 mm Hg

  • AVA typically ≤1.0 cm2 (or AVAi ≤0.6 cm2/m2) but may be larger with mixed AS/AR

  • LV diastolic dysfunction

  • LV hypertrophy

  • Pulmonary hypertension may be present

  • Exertional dyspnea or decreased exercise tolerance

  • Exertional angina

  • Exertional syncope or presyncope

D2Symptomatic severe low-flow/low-gradient AS with reduced LVEF
  • Severe leaflet calcification with severely reduced leaflet motion

  • AVA ≤1.0 cm2 with

    resting aortic Vmax <4 m/s or

    mean ΔP <40 mm Hg

  • Dobutamine stress echocardiography shows AVA ≤1.0 cm2 with Vmax ≥4 m/s at any flow rate

  • LV diastolic dysfunction

  • LV hypertrophy

  • LVEF <50%

  • HF

  • Angina

  • Syncope or presyncope

D3Symptomatic severe low-gradient AS with normal LVEF or paradoxical low-flow severe AS
  • Severe leaflet calcification with severely reduced leaflet motion

  • AVA ≤1.0 cm2 with aortic Vmax <4 m/s or mean ΔP <40 mm Hg

  • Indexed AVA ≤0.6 cm2/m2 and

  • Stroke volume index <35 mL/m2

  • Measured when patient is normotensive (systolic BP <140 mm Hg)

  • Increased LV relative wall thickness

  • Small LV chamber with low stroke volume

  • Restrictive diastolic filling

  • LVEF ≥50%

  • HF

  • Angina

  • Syncope or presyncope

AR indicates aortic regurgitation; AS, aortic stenosis; AVA, aortic valve area; AVAi, aortic valve area indexed to body surface area; BP, blood pressure; HF, heart failure; LV, left ventricular; LVEF, left ventricular ejection fraction; ΔP, pressure gradient; and Vmax, maximum aortic velocity.