CAC score

CAC score computes percentile ranks and estimates "coronary age" from cardiac CT-derived coronary artery calcification (CAC) scores using population-based reference values from the DanRisk and DANCAVAS cohorts to support cardiovascular risk assessment.

Key Features:

• Population-based reference values: Derives reference values and percentile curves from two population-based cardiac CT screening cohorts, DanRisk and DANCAVAS.
• Age- and gender-specific percentiles: Generates percentile curves stratified by age and gender.
• Zero-score handling: Accounts for the prevalence of zero CAC scores when deriving percentiles.
• Log-transformation: Log-transforms positive CAC scores prior to regression.
• Non-parametric regression: Applies non-parametric regression of log-transformed CAC against age separately for each gender.
• Inputs and outputs: Accepts sex, age, and measured CAC score as inputs and outputs percentile rank and estimated coronary age.
• Percentile comparison: Reports comparisons against key percentiles (25%, 50%, 75%, 90%) and produces graphical representations of the score versus population percentiles.

Scientific Applications:

• Cardiovascular risk stratification: Facilitates assessment of individual cardiovascular risk by comparing CAC scores to age- and gender-specific population percentiles.
• Clinical communication and decision support: Supports categorization of calcification severity (low, moderate, high) to inform preventive strategies and clinician–patient discussions.
• Population-level analysis: Enables analysis of CAC distribution across age and gender using DanRisk and DANCAVAS reference data.

Methodology:

Reference CAC scores from the DanRisk and DANCAVAS cohorts were used; positive CAC scores were log-transformed, non-parametric regression against age was performed separately by gender while accounting for the prevalence of zero CAC scores, percentile ranks and percentile curves were calculated, and coronary age estimates were derived from these curves.