AVC Calcium Score for AS

CT Aortic Valve Calcification — Sex-Specific Severity Thresholds

Sex-specific aortic valve calcium (AVC) thresholds from non-contrast CT for confirming severe AS, particularly useful in low-flow low-gradient presentations where echo-derived AVA and gradients are discordant. Recommended by 2020 ACC/AHA and 2021 ESC valvular heart disease guidelines.

Sex

Male Female

AVC Score (Agatston Units) From non-contrast cardiac CT (same protocol as coronary calcium scoring)

Severity	Men (AU)	Women (AU)
Severe AS unlikely	< 1600	< 800
Severe AS likely	≥ 2000	≥ 1200
Gray zone	1600–1999	800–1199
Very severe AS	≥ 3000	≥ 1600

Clinical Application

Primary use: Resolving discordant echo findings in low-flow low-gradient AS (AVA <1.0 cm² with mean gradient <40 mmHg).
Gray zone: Consider additional testing (DSE, CMR, or repeat imaging). Clinical context and symptoms should guide management.
Women: Develop hemodynamically significant AS at lower calcium burdens than men — sex-specific thresholds are essential.
Bicuspid valves: May have lower calcium loads for the same hemodynamic severity — interpret with caution.

Reference

Clavel MA et al. (2018) — Aortic valve calcium scoring by cardiac CT for predicting severe AS. Heart. 104:1495–1501.

AVC Calcium Score for AS

Results

Sex-Specific Thresholds

Clinical Application

Reference