Evaluation of Coronary Artery Disease Plaques Using Coronary CT Angiography in a High-Risk Population.

Background Coronary artery disease (CAD) remains a leading cause of cardiovascular morbidity and mortality. Coronary computed tomography angiography (CCTA) enables non-invasive assessment of coronary stenosis, plaque burden, and high-risk plaque (HRP) morphology, offering incremental risk information beyond traditional clinical scoring. Objective The objective of this study was to evaluate coronary plaque characteristics and the prevalence of HRP features on CCTA in high-risk patients presenting with stable chest pain at a tertiary care center in Assam, India, and to assess their association with the severity of coronary artery disease. Methods This hospital-based cross-sectional study included 40 patients with stable chest pain and major cardiovascular risk factors (type 2 diabetes mellitus, hypertension, dyslipidemia, smoking, and/or family history of CAD) referred for CCTA evaluation from November 2023 to October 2024. All patients underwent 128-slice CCTA with coronary artery calcium (CAC) scoring. Plaque presence, distribution, morphology, and HRP features - including low-attenuation plaque, napkin-ring sign, spotty calcification, and positive remodeling - were assessed along with the Coronary Artery Disease-Reporting and Data System (CAD-RADS) grading. Statistical analysis was performed using Fisher's exact test. Results CAD was detected in 28 of 40 patients (70%). High-risk (vulnerable) plaques were identified in 22 patients (55%), while stable calcified plaques were present in six patients (15%), and no plaque was detected in 12 patients (30%). Among HRP features, low-attenuation plaque was most common (n = 12, 30%), followed by napkin-ring sign (n = 7, 17.5%), spotty calcification (n = 2, 5%), and positive remodeling (n = 1, 2.5%). The left anterior descending artery was the most frequently involved vessel (n = 19, 47.5%). The majority of patients fell into the CAD-RADS 3 category (n = 15, 37.5%). A CAC score of 101-200 was the most prevalent range (42.5%). A statistically significant association was found between the number of cardiovascular risk factors and the presence of HRP (p = 0.033); however, no significant correlation was observed between the degree of coronary calcification and HRP features. Conclusion CCTA is a valuable non-invasive modality for detecting and characterizing coronary plaques in high-risk patients with stable chest pain. The high prevalence of HRP features, particularly in individuals with multiple cardiometabolic risk factors, underscores the role of CCTA in coronary risk stratification and guiding early preventive management.