Abstract 17791: Yield of Different Approaches for Screening for Cardiovascular Disease in Asymptomatic Diabetics

Abstract

Introduction: While diabetes has long been considered a coronary heart disease equivalent, there is increasing evidence to suggest that not all individuals with diabetes have cardiovascular disease, and it is unclear how best to risk stratify this population. We sought to compare the yield of testing for pre-clinical atherosclerosis with various approaches. Methods: A group of 98 asymptomatic subjects with type 2 diabetes mellitus (T2DM) without known coronary artery disease (CAD) were enrolled in a prospective study and underwent carotid ultrasound, exercise treadmill testing (ETT), coronary artery calcium (CAC) scoring, and coronary computed tomography angiography (CTA). CTA was used as the reference standard for CAD. Results: Of 98 subjects (average age 55±6, 64% female, 22 on insulin, mean A1c 7.3%), 43 (44%) had coronary plaque detectable on CTA, and 38 (39%) had CAC score > 0. By CTA, 16 (16%) had coronary stenosis ≥ 50%, including 3 subjects with CAC=0. Subjects with coronary plaque had greater prevalence of carotid plaque (58% vs. 38%, p=0.01) and greater carotid intima media thickness (0.80±0.20 mm vs. 0.70±0.11mm, p=0.02). However, 18 of the 55 subjects (33%) with normal CTA had carotid plaque. Eight subjects had a positive ETT, of whom 5 had ≥ 50% coronary stenosis and 2 had <50% stenosis, but there was no difference in METS achieved between subjects with and without plaque (8.2 vs. 8.7, p=0.19). Test characteristics of different imaging modalities for prediction of coronary plaque are shown in Figure 1. Conclusion: Among asymptomatic subjects with T2DM, a majority (56%) had no CAD by CTA. CAC was the most accurate screening modality for detection of CAD while ETT and carotid ultrasound had a limited sensitivity. Interestingly, 33% of subjects with normal CTA had carotid plaque. Further studies are needed to better characterize stroke risk in such patients and whether there is a role for screening for carotid plaque in diabetics without CAC or with normal CTA.