Aspirin use for primary prevention in patients at high risk with diabetes mellitus (DM) is often recommended under the assumption that most patients with DM have coronary artery disease (CAD). However, not all patients may have CAD. The present study evaluated, in 425 patients at high risk with DM (without chest pain syndrome or a history of cardiac disease), the prevalence of CAD on coronary computed tomography angiography (CTA). Moreover, the association between the presence and number of traditional cardiovascular (CV) risk factors and CAD (on coronary CTA) was evaluated. The median coronary artery calcium score was 29 (interquartile range 0 to 298). On coronary CTA, 116 patients (27%) had no CAD (defined as <30% stenosis). Of the 309 patients (73%) with any CAD (>= 30% stenosis), 35% had obstructive CAD (>= 50% stenosis). The number of traditional CV risk factors was not associated with the presence of any CAD (>= 30% stenosis; p = 0.18) or obstructive CAD (>= 50% stenosis; p = 0.13). Hypertension was the only traditional CV risk factor associated with a higher frequency of any CAD (>= 30% stenosis; odds ratio = 2.21, 95% CI 1.43 to 3.41, p <0.001) and obstructive CAD (>= 50% stenosis; odds ratio 2.03, 95% CI 1.33 to 3.11, p = 0.001). In conclusion, in patients at high risk with DM without chest pain syndrome, any CAD was ruled out by coronary CTA in 27%, whereas 65% of the patients did not have obstructive CAD. The number of CV risk factors was not associated with the presence of CAD. Hypertension was the only traditional CV risk factor that was associated with a higher frequency of CAD. These observations support potential use of coronary CTA to tailor aspirin therapy in patients at high risk with DM. (c) 2016 Elsevier Inc. All rights reserved.