High-Risk Plaque Characteristics in Patients with Suspected Stable Coronary Artery Disease and Impaired Glucose Tolerance: A Coronary Computed Tomography Angiography Study

Impaired glucose tolerance (IGT), a prediabetic state, is a known risk factor for coronary artery disease (CAD). Low-attenuation plaque (LAP) lesions are associated with a high risk of coronary events. We aimed to evaluate high-risk plaque characteristics in LAP lesions between patients with IGT and normal glucose tolerance (NGT) in patients suspected for stable CAD. Coronary computed tomography angiography (CCTA) identified LAP lesions and assessed plaque volumes, burdens, and high-risk plaque features. Glycemic tolerance was stratified using oral glucose tolerance tests. Among 148 patients, 202 LAP lesions were identified, with 93 patients classified as NGT and 55 as IGT. Patients with IGT had a significantly higher prevalence of LAP lesions compared with NGT (<i>p</i> = 0.007). LAP volume was higher in IGT (16.46 ± 12.52 mm³) compared with NGT (12.66 ± 9.72 mm³, <i>p</i> = 0.01), but this association did not persist in multivariate analysis. The LAP burden was greater in IGT (10.79 ± 6.84%) than NGT (8.62 ± 5.93%, <i>p</i> = 0.02), and the napkin-ring sign was more frequent in IGT (12%) versus NGT (5%, <i>p</i> = 0.02); these associations remained significant in multivariate analysis. Patients with IGT had a higher LAP burden and higher frequency of napkin-ring signs. These findings may help explain the common occurrence of prediabetes in patients with acute myocardial infarction.