Sub-Agatston Coronary Calcification on Non-Contrast Cardiac CT and Cardiovascular Risk
European Journal of Preventive Cardiology
Conventional Agatston scoring only counts coronary calcium above the 130 HU threshold – but clinically relevant plaque signal may lie just beneath it.
In nearly 3,000 adults from the CLARIFY screening registry and SCOT-HEART chest-pain trial, investigators tested the Vulnerable Calcium Index (VCI), a non-contrast CT metric that expands standard calcium lesions down to 110HU to capture low-density “sub-Agatston” calcium.
VCI independently predicted major adverse cardiovascular events beyond clinical risk factors and Agatston score, improved risk discrimination and correlated with high-risk plaque features on coronary computed tomography angiography – suggesting a simple add-on to calcium scoring could refine risk stratification.
