Clinical Disease

cardiac

Must-have

Severe Aortic Stenosis: Grading & Thresholds

ACC/AHA 2020 severity criteria and ASE/EACVI 2017 integrated echo assessment for severe valve disease — symptoms and LV dysfunction trigger intervention.

Severe aortic stenosis is defined by a mean transvalvular gradient ≥40 mm Hg and a valve area ≤1.0 cm²; symptoms attributable to severe AS or LV systolic dysfunction are major indications for valve intervention, with complex decisions routed through a multidisciplinary heart-valve team per ACC/AHA 2020.

If you forget

Headline: Severity = mean gradient ≥40 mm Hg AND valve area ≤1.0 cm² (ACC/AHA 2020).

Board trap

Single-parameter grading misleads: ASE/EACVI 2017 explicitly rejects single-number grading and requires an integrated echocardiographic assessment using peak velocity, mean gradient, valve area, flow state, image quality, and internal consistency before declaring severity.

Key numbers

Mean gradient ≥40 mm Hg supports high-gradient severe aortic stenosis (ACC/AHA 2020)
Valve area ≤1.0 cm² is typical of severe aortic stenosis (ACC/AHA 2020)
Worked example in source: valve area 0.7 cm² with mean gradient 48 mm Hg = severe
Symptoms or LV systolic dysfunction = major indication for valve intervention (ACC/AHA 2020)

Reviewed Sep 16, 2026 for clinical accuracy by BoardsBridge Editorial Process

Uri Rozen, MD — Licensed Physician, Israel

Source guidelines: ACC AHA Valvular Heart Disease 2020 · ACC AHA Valvular Heart Disease 2020 · ASE EACVI Aortic Stenosis 2017

Re-review cadence: 12 months from reviewed date.

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Related on BoardsBridge

Card ID: ms-severe · Path: aba.cardiac.valvular.ms-severe