Aortic Stenosis Severity

About this calculator

Interactive grading of aortic stenosis (AS) based on ESC 2025 guidelines.

Normal Values

Aortic Stenosis: Diagnosis and Classification

Aortic stenosis (AS) is the most common acquired valvular heart disease in the Western world. Echocardiography is the central tool for diagnosis and follow-up. This calculator supports classification according to the current 2025 ESC/EACTS guidelines.

Key Parameters for Severity Assessment

Severe Aortic Stenosis (classical):

• Vmax ≥ 4.0 m/s
• Mean gradient ≥ 40 mmHg
• AVA ≤ 1.0 cm² (or ≤ 0.6 cm²/m² indexed)

Simultaneous fulfillment of all three criteria confirms the diagnosis.

Low-Flow, Low-Gradient AS (LFLG-AS)

If AVA ≤ 1.0 cm² and mean gradient < 40 mmHg with reduced EF (<50%), LFLG-AS should be suspected.

• Low flow must be confirmed: SVi ≤ 35 mL/m²

To differentiate true severe AS from pseudo-severe AS, the following are equally recommended:

• Dobutamine stress echocardiography
• CT aortic valve calcium scoring (AVCS)

Paradoxical LFLG-AS

With preserved EF (≥50%), AVA ≤ 1.0 cm², low gradient, and low flow (SVi ≤ 35 mL/m²): CT calcium score is decisive for confirming severity.

When to Intervene

Intervention (TAVI or surgical aortic valve replacement) is indicated in:

Symptomatic severe AS:

• General recommendation for intervention in all patients with reasonable life expectancy

Asymptomatic patients: Intervention is recommended if:

• LVEF < 50% without another identifiable cause
• Very severe AS (Vmax ≥ 5.0 m/s)
• Abnormal exercise test (symptoms or drop in blood pressure compared to baseline)