Abstract 2507: Serial Changes in Plaque Characteristics in Patients with Type 2 Diabetes Mellitus Using Integrated Backscatter Intravascular Ultrasound
Background: Several studies have demonstrated type 2 diabetes is associated with accelerated atherosclerosis, which results in an increased risk of coronary vascular events. However, serial changes in plaque characteristics have not been well defined. Recently, assessment of plaque composition has become possible using an integrated backscatter intravascular ultrasound system (IB-IVUS). Accordingly, we evaluated the progression of coronary atherosclerosis in patients with type 2 diabetes using IB-IVUS, focusing on changes in the lipid-rich component.
Methods: Fifteen patients with type 2 diabetes and 19 non-diabetic patients were enrolled in the study. Non-culprit coronary lesions with mild to moderate stenosis were measured by conventional and IB-IVUS parameters using a 40-MHz (motorized pullback 0.5 mm/s) intravascular catheter. A total of 40 IB-IVUS images were recorded at 0.5 mm intervals along a 20 mm length of each target plaque. Six months later a follow up IVUS examination was performed of the same coronary segment imaged at the baseline examination.
Results: Mean HbA1c level decreased from 7.6% to 6.8% in the patients with diabetes. A total of 46 plaques were examined (18 diabetic vs. 28 non-diabetic). At baseline, there were no significant differences in conventional IVUS parameters such as vessel, lumen or plaque volumes between the diabetic and non-diabetic patients. The percentage lipid volume (% LV) analyzed by IB-IVUS at baseline was also not significantly different between the two groups (diabetic: 45.0 ± 9.4 %, non-diabetic: 41.2 ± 13.5 %; P=N.S.). However, % LV at the follow up examination was significantly greater in patients with diabetes (diabetic: 50.1 ± 11.5%; non-diabetic: 39.9 ± 13.2%; P=0.01). Moreover, the change in % LV from baseline was significantly greater in diabetic patients compared to non-diabetic patients (P<0.05). In contrast, there were no significant differences in conventional IVUS parameters even at the follow up examination.
Conclusions: This is the first report clarifying serial changes in non-culprit plaque characteristics in patients with diabetes. The lipid-rich component of non-culprit plaque in patients with type 2 diabetes was increased, indicating an increase in plaque vulnerability.