Coronary atherosclerosis on coronary CT angiography in individuals with and without type 2 diabetes

We aimed to evaluate the associations of type 2 diabetes, glycemic control, and diabetes duration with coronary artery disease (CAD) and the extent of coronary atherosclerosis on computed tomography angiography (CCTA). This retrospective cohort study included 4,211 consecutive individuals undergoing CCTA for suspected CAD between January 2022 and December 2023; 341 (8.1%) had type 2 diabetes. The extent of coronary atherosclerosis was assessed using the segment involvement score (SIS), defined as the number of coronary segments containing plaque, as well as the number of segments containing non-calcified and calcified plaque. Multivariable regression models evaluated associations with type 2 diabetes. Among individuals with type 2 diabetes, exploratory analyses evaluated the associations of glycated hemoglobin A1c (HbA1c) and diabetes duration with CCTA outcomes. Individuals with type 2 diabetes more frequently had CAD (86% vs. 68%, p < 0.001) and obstructive CAD (36% vs. 20%, p < 0.001). Type 2 diabetes was independently associated with CAD (odds ratio [OR] 2.03, 95% confidence interval [CI] 1.42–2.91), obstructive CAD (OR 1.72, 95%CI 1.31–2.26), SIS (rate ratio [RR] 1.25, 95% CI 1.13–1.40), the number of segments containing non-calcified plaque (RR 1.25, 95% CI 1.09–1.42) and calcified plaque (RR 1.34, 95% CI 1.17–1.53). At the median age of 59 years, the higher SIS associated with type 2 diabetes corresponded to an age-equivalent difference of 9.9 years (95% simulation interval 6.2–15.1). In exploratory analyses, higher HbA1c was associated with a greater number of segments containing non-calcified plaque (RR 1.08, 95% CI 1.00–1.15 per 1% increase), while longer diabetes duration was associated with obstructive CAD (OR 1.21, 95% CI 1.02–1.44 per 5-year increase). Type 2 diabetes was associated with a greater extent of coronary atherosclerosis among individuals referred for CCTA, with the higher SIS corresponding to an age-equivalent difference of almost a decade at the median age of 59 years. In exploratory analyses, HbA1c was associated with greater non-calcified plaque involvement. What is currently known about the topic? Individuals with type 2 diabetes have an increased burden of coronary artery disease and a higher risk of cardiovascular events. Coronary plaque burden and composition assessed by coronary CT angiography provide important prognostic information. What is the key research question? How are type 2 diabetes, glycemic control and diabetes duration associated with coronary artery disease, and the extent of calcified and non-calcified plaque on coronary CT angiography? What is new? Type 2 diabetes was independently associated with more extensive coronary artery disease and a greater number of segments containing calcified and non-calcified plaque. In an exploratory analysis, HbA1c was independently associated with a greater number of segments containing non-calcified plaque. Our findings provide a comprehensive characterization of the coronary atherosclerotic phenotype associated with type 2 diabetes. How might this study influence clinical practice? These findings provide further insight into the coronary atherosclerotic phenotype of type 2 diabetes.