Aortic Calcification as a Surrogate Marker and Predictor of Risk of Coronary Artery Disease: A Hospital-Based Cross-Sectional Analytical Study in Northeast India

Coronary artery disease (CAD) is the leading cause of cardiovascular mortality worldwide. Coronary artery calcium (CAC) scoring is the most validated imaging biomarker for subclinical atherosclerosis, but its utility is constrained by cost, radiation, and limited access. Aortic calcification (AC)—frequently encountered as an incidental finding on routine computed tomography (CT)—shares common pathophysiological mechanisms with coronary atherosclerosis and may serve as a practical surrogate marker. This hospital-based cross-sectional analytical study was conducted at a tertiary care referral centre in Northeast India, following Institutional Ethics Committee approval and in accordance with the Declaration of Helsinki. Ninety-six adult patients (>30 years) with clinically suspected CAD undergoing CT coronary angiography were prospectively enrolled by consecutive sampling. Coronary artery and aortic (thoracic and abdominal) calcium scores were independently quantified using Agatston's method on a 128-slice multidetector CT scanner (Siemens SOMATOM Definition AS + , Germany). Agreement was assessed by kappa statistics; correlations, by Pearson and Spearman coefficients; and prediction, by simple linear regression. The mean age was 58.69 ± 12.80 years; males constituted 53.1%. The mean CAC score was 120.26 ± 238.71 Agatston Units (AU) and the mean total aortic calcium score (ACS) was 1,206.26 ± 1,869.07 AU. A strong positive correlation was found between total ACS and CAC (Pearson r = 0.861, Spearman ρ = 0.874; both p <0.001). Kappa analysis showed near-perfect agreement (κ = 0.812, p = 0.023). Linear regression demonstrated that ACS independently predicted coronary artery calcium, accounting for 74.1% of its variance (β = 0.861, R 2 = 0.741, 95% CI: 0.095–0.122, p <0.001). Thoracic and abdominal ACS showed strong intercorrelation (r = 0.846, p <0.001). Both scores increased progressively with advancing age. Dyslipidemia was the only cardiovascular risk factor significantly associated with calcium burden (p = 0.032 for CAC; p = 0.012 for ACS). AC demonstrates strong concordance and predictive correlation with coronary artery calcification, supporting its role as a surrogate imaging biomarker for coronary atherosclerotic burden. Opportunistic assessment of aortic calcium on routine CT may meaningfully enhance cardiovascular risk stratification, especially where dedicated cardiac imaging is unavailable.