Definition of Aortic Stenosis Severity

Aortic valve area can be calculated by using the principle of conservation of mass — “What comes in must go out”.

Aortic valve area indexed to body surface area should be considered for the large and small extremes of body surface area.

AVA cm²

Normal – 3.0-4.0

Mild – >1.5

Moderate – 1.0-1.5

Severe – <1.0

AVAI  cm²/m²

Mild – >0.85

Moderate – >0.60-0.85

Severe – >0.6

For patients with prosthetic aortic valves, patient-prosthesis mismatch is suspected when effective orifice area (EOA) indexed to body surface area <0.85 to 0.9 cm²/m². Patient-prosthesis mismatch is considered severe when EOA index <0.65.