Assessment of coronary plaque characteristics by optical coherence tomography in patients with diabetes mellitus complicated with unstable angina pectoris

Abstract

Background Diabetic patients are characterised by poorer prognosis and more cardiovascular complications compared with non-diabetic patients, which may be due to metabolic abnormalities and atherosclerotic plaque characteristics. Methods Patients with unstable angina pectoris were enrolled in the study and divided into diabetes mellitus (DM) (patients, n = 25; plaques, n = 42) and non-DM (patients, n = 53; plaques, n = 65) groups according to their DM history. Optical coherence tomography (OCT) examinations were performed on all patients, and images were analysed by two independent investigators. Fibrous cap thickness was measured at the thinnest point of each plaque. The presence of plaque disruption, dissection, erosion, thrombosis and calcification were also noted. Results Calcified plaques in the DM group were significantly greater than those in the non-DM group (42.9% vs. 23.1%; p = 0.03). Thin-cap fibroatheroma (TCFA) were detected, and no significant difference was found in the frequencies (42.9% vs. 52.3%; p = 0.34) and fibrous cap thickness (57.08 ± 6.20 μm vs. 56.11 ± 9.23 μm, p = 0.74) between the DM and non-DM groups. Thrombus and plaque erosion were similar in the two groups, but the frequency of dissection in the DM group was greater than that in the non-DM group (21.4% vs. 7.7%, p = 0.04). The high sensitivity C-reactive protein between the two groups was similar (0.44 ± 0.20 mg/dl vs. 0.46 ± 0.15 mg/dl, p = 0.83). Conclusion Higher calcification and dissection were detected in diabetic patients with unstable angina pectoris, and the difference in coronary plaque characteristics can explain the difference in clinical prognoses between DM and non-DM patients.