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cardiology

Aortic Stenosis Severity Classification (ACC/AHA)

Classifies aortic stenosis from echocardiographic parameters per the 2020 ACC/AHA valvular heart disease guideline (stages B, C1, D1; low-gradient AS flagged). Guides timing of intervention (TAVI or SAVR).

Score interpretation

No Haemodynamically Significant AS (Vmax < 2 m/s) 0

Aortic sclerosis or normal valve — stage A (at risk) if the valve is thickened or calcified.

→ No AS-specific follow-up; reassess if a murmur or symptoms develop.

Mild AS (Stage B) 1

Progressive AS: Vmax 2.0–2.9 m/s or mean gradient < 20 mmHg.

→ Serial echo in 3-5 years; risk factor modification; no intervention

Moderate AS (Stage B) 2

Progressive AS: Vmax 3.0–3.9 m/s or mean gradient 20–39 mmHg.

→ Echo every 1–2 years (ACC/AHA 2020); review promptly if symptoms develop.

AVA ≤ 1.0 cm² with Low Velocity / Gradient — Possible Low-Gradient Severe AS 3

Discordant grading: severe by valve area but not by Vmax or gradient (consider stage D2 if LVEF < 50 %, D3 if LVEF ≥ 50 % with small stroke volume, or measurement error).

→ Heart valve team review: check measurements, LVEF and stroke volume index; dobutamine stress echo or CT calcium score.

Severe AS — Asymptomatic (Stage C1) 4

Vmax ≥ 4 m/s or mean gradient ≥ 40 mmHg without symptoms.

→ 6-monthly echo; TAVI or SAVR if LVEF < 50%, very severe AS, or exercise-induced symptoms

Severe AS — Symptomatic (Stage D1) 5

Vmax ≥ 4 m/s or mean gradient ≥ 40 mmHg with symptoms.

→ Valve intervention (TAVI or SAVR) is indicated: expedite heart valve team review; avoid strenuous activity.

Interpretation bands for the AS Severity. Apply clinical judgement and local guidance.

References

Related

Curated clinical cross-links plus same-class fallbacks.

Drugs
Pathways

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.